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City and County of Denver storm drainage master plan, 2014

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Title:
City and County of Denver storm drainage master plan, 2014
Creator:
Enginuity
Icon Engineering, In.
Matrix Design Group
Olsson Associates
San Engineering, LLC
Zoeller Consulting, LLC
Place of Publication:
City and County of Denver
Publisher:
Department of Public Works, City and County of Denver
Publication Date:
Language:
English

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Subjects / Keywords:
Storm sewers
Master plans

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DENVER
PUBLIC WORKS


FILE; G;^is_prajects\DenverDrainaga_2Dl4\active\apps\Mapbook'.StudY_Area.mxd, 6/21/2014, chris_martin
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Denver Storm Drainage Master Plan
September 2014
DENVER STORM DRAINAGE MASTER PLAN
2014
PROJECT ID PC70812 908
Prepared for:
The City and County of Denver
Department of Public Works
DENVER
PUBLIC WORKS
Prepared by:
Enginuitf
WGlNEtkSNG
SOLUTIONS
icon Matrix in:;
EMGIflEERIMG, IMC. *
OLSSON
ASSOCIATES
San Engineering llc
ZOELLER
CONSUiTINS UC___
ccmMunmn


Denver Storm Drainage Master Plan
Corrections
Cost revised for projects (09/29/2014):
o 3900-04-B
o 5100-01-N
o 5200-03-DD
September 2014


Denver Storm Drainage Master Plan
Table of Contents
ACKNOWLEDGMENTS...............................................................2
1.0 BACKGROUND..............................................................3
1.1 Executive Summary.................................................... 3
1.2 Introduction....................................................... 5
1.3 Goals of the Storm Drainage Master Plan...............................6
1.3.1 Management Interviews...............................................6
1.3.2 Additional Studies.............................................. 6
1.4 Plan Formulation.................................................. 7
1.4.1 Geology.............................................................7
1.4.2 Climate.............................................................7
1.4.3 Topography..........................................................8
1.4 4 Flood History.......................................................8
1.4 5 Existing Conditions................................................14
1.4.6 Future Development.................................................14
2.0 MAJOR DRAINAGEWAYS.....................................................14
2.1 South Platte River (Basin 0000)......................................14
2.2 Second Creek (Basin 3500)............................................14
2.3 First Creek (Basin 3700).............................................15
2.4 Irondale Gulch (Basin 3900)......................................... 15
2.5 Clear Creek (Basin 4300)............................................ 15
2.6 Sand Creek (Basin 4400)..............................................15
2.7 Westerly Creek (Basin 4401)..........................................15
2.8 Montclair (Basin 4500).,, ,, ..................,, .................16
2.9 Cherry Creek (Basin 4600)............................................16
2.10 Goldsmith Gulch (Basin 4601).........................................16
2,1! Sloan's Lake (Basin 4700)............................................17
2.12 Lakewood Gulch (Basin 4800)...........................................17
2 13 Dry Gulch (Basin 4801). .............................................17
2.14 Weir Gulch (Basin 4900)............................................ 17
2.15 Sanderson Gulch (Basin 5100).........................................17
2.16 Harvard Gulch (Basin 5200)....................................... 17
2.17 West Harvard Gulch (Basin 5300)......................................18
2.18 Bear Creek (Basin 5500)..............................................18
2.19 Marston Lake North (Basin 5501).................................... 18
3.0 CAPITAL IMPROVEMENTS PROGRAM...........................................19
3.1 Cost Modeling...................................................... 19
3.2 Summary of Capital Costs.............................................19
4.0 STUDY REFERENCES.......................................................26
September 20/4
MAPPING
Study Area Map
Index Map
Areas of Change Map
Collection System Maps
TECHNICAL APPENDICES for each collection system
(under separate cover)
Imperviousness Computations
Routing Schematics
CUHP Model Input/Output
UDSWM Model Input/Output
Work Maps (Color l-inch= 400 Aerial)
Detailed Project Costs
Page 1


Denver Storm Drainage Master Plan
ACKNOWLEDGMENTS
The project team wishes to acknowledge the various individuals in the City and County of Denver
who assisted in the preparation of this update to the Storm Drainage Master Plan study for the City
and County of Denver:
Michael Anderson, Denver Public Works
Walt Hi me, Development Services
Saeed Farahmandi, Denver Public Works
Lupe Martinez, Denver Public Works
Bruce Uhemik, Denver Public Works
Kimberly Watanabe, Denver Public Works
The following members of the consultant project team contributed significant time and effort to the
preparation of this updated master plan report:
Enginuity Engineering Solutions, LLC Team:
Don Jacobs, Project Manager
Beck Anderson
Jeff Sickles
ICON Engineering, Inc. Team:
Craig Jacobson, Project Manager
Eben Dennis
Brian LeDoux
Matrix Design Group, Inc. Team:
Robert Krehbiel, Project Manager
Hung Teng Ho
Jeff Clonts
Chris Martin
Wilson Wheeler
Olsson Associates Team:
Deb Ohlinger, Project Manager
Amy Gabor
David Krickbaum
Jason Messamer
San Engineering, LLC
John Dinkel
Eduardo San
Zoeller Consulting, LLC
Lisa Zoeller
September 2014
Cover Photo Credits:
Cover design by Janae Newman, Graphic Design-Olsson Associates
Cover Image: Copyright Thinkstock 2014, downloaded using Olsson Associates
subscription license, May not be used in other materials.
Other Images:
Historic: date and source unknown
Fire Trucks: date and source unknown
August 2002: source unknown
August 18, 2004: source unknown
September 12, 2013: Tony Ryan
Page 2


Denver Storm Drainage Master Plan
1.0 BACKGROUND
1.1 Executive Summary
In accordance with Denver Revised Municipal Code, Division 4, Section 56-110, Denvers Storm
Drainage Master Plan is updated every 5 years in order to identify and alleviate present and future
drainage problems of the city. Consequently, the plan is subject to regular modifications and
holders of the plan are therefore encouraged to contact the City and County of Denver Department
of Public Works Engineering Division, Capital Projects Management Group for the most currently
available information
Drainage basins at Denver International Airport (D1A) have been excluded from this update in
accordance with DI As independent implementation of its own storm drainage and water quality
infrastructure.
Urban stormwater management within the City and County of Denver has increasingly become a
critical infrastructure element as major improvement programs and asset re-development efforts are
implemented across the City, The improvements identified herein form the basis for identifying
needed storm drainage capital projects throughout the City in its Capital Improvement Program.
The total project cost to upgrade the Citys storm drainage infrastructure, to meet minimum current
drainage criteria in the Recommended Plan for the entire City, is estimated to be $1,478,025,513 in
2013 dollars.
This Master Plan updates and refines the previous Storm Drainage Master Plan to incorporate
recently-constructed storm drainage facilities and the findings and recommendations of various
studies conducted in the years following publication of the last Storm Drainage Master Plan,
In addition, this update identifies topographic drainage basin boundaries and thalwegs, Potential
Inundation Areas where localized flooding in excess of street drainage criteria is possible and
Significant Flooding Locations reported since the year 2000, This update also identifies locations of
flood control improvements needed along drainageways in studies conducted by the Urban Drainage
and Flood Control District (UDFCD) in partnership with the City and County of Denver
Drainage Basins and Thalwegs
Hydrologic modeling of the existing storm drainage system reveals that two distinct drainage basins
exist: 1) Storm Drainage Collection System Basins defined by the existing storm drainage
collection system catchments for minor storm conveyance designs, and 2) Topographic Drainage
Basins defined by overland flow paths related to larger storm events. Both are shown in the Master
Plan in order to clearly illustrate where storm drain systems direct storm runoff for the minor storm
event and where larger storm events will produce surface runoff crossing collection system
boundaries.
In addition, thalwegs, or natural drainage paths, are shown in order to identify the major overland
flow paths that storm runoff would follow in storm events that produce runoff in excess of the
existing storm drainage collection system capacities. Not all thalwegs are shown, only the most
significant for each drainage basin,
September 2014
Potential Inundation Areas
Potential Inundation Areas (PIAs) shown in the Storm Drainage Master Plan are areas where
stormwater has been reported to collect in depths exceeding 12 during storm events and where
various studies have identified the potential for water depths greater than 12 in a major storm
event. The areas depicted represent current best-available information of these hazards. PI As are
shown so that the information is accessible to Denver residents and property owners, PlAs are not
to be confused with floodplains mapped in accordance with Federal Emergency Management
Agency (FEMA) guidelines for the National Flood Insurance Program (NFtP),
PlAs are identified due to more localized flooding issues and are not shown on the NFIP Flood
Insurance Rate Maps and therefore flood insurance is not federally-mandated and most floodplain-
specific regulations do not apply. However, it is important to note that in the absence of better-
available information, the flood depths defined in PlAs may be used to determine the Finished Floor
Elevations (FFE) and Minimum Lowest Opening Elevations (MLOE) for new development and re-
development.
Property owners in PlAs are encouraged to implement floodproofing measures (see the City and
County of Denver Flood Protection Handbook at www.denvergov.ora/tabid/391460/Default.aspx )
and explore the need for flood insurance since flood damages are not covered by a typical
homeowner policy. A separate flood insurance policy is required to cover contents that may be
damaged due to flooding. Property owners can insure their buildings and contents, and renters can
insure only their contents, Additional flood insurance information is available at
www.floodsmart.eov.
These areas do not reflect all such hazards throughout the City and County of Denver but represent
the best available information based on flooding reports and drainage studies. Other areas may be
identified in the course of additional more detailed studies and storm events.
Significant Flooding Locations
Significant Flooding Locations shown with red stars are locations where significant flooding
and/or property damage have been reported since the year 2000 to the City and County Department
of Public Works-Storm Drainage Planning, and have not yet been mitigated with storm drainage
improvements. They do not reflect all reports received, only the most severe.
UDFCD Study Recommendations
The location of flood control improvements identified in Major Drainageway Planning studies and
Outfall Systems Planning studies conducted by the UDFCD are identified in order to better
coordinate work efforts by the Public Works storm drainage Capital Improvement Program, the
Public Works bridge Capital Projects Program, Department of Parks and Recreation improvements
and the UDFCD
Hydrologic Modeling for the existing storm drainage network was conducted using the Colorado
Urban Hydrograph Procedures (CLIHP 2000) and the Urban Drainage Storm Water Management
Model (UDSWMM) version i .4 6 developed by the UDFCD. Modeling from more recent studies
was conducted using CUHP 2005 and EPA Storm Water Management Model (EPASWMM)
version 5.0.022. Results have been incorporated into this update in some drainage basins in order to
retain the updated modeling from those studies. The results were then used to identify areas where
Page 3


Denver Storm Drainage Master Plan
existing storm drainage systems needed to be enlarged to meet the current level of service and
where new storm drainage systems were needed,
Land-Use impervious values are based on Blueprint Denver: An Integrated Land Use and
Transportation Plan adopted in 2002 as a supplement to the Denver Comprehensive Plan 2000
(herein referred to as Blueprint Denver'), which prepares the City for continued urbanization and
redevelopment by identifying Areas of Stability and Areas of Change. This information is
supplemented with surface area impervious data available in Denvers G1S database.
Also, the City has implemented a myriad of stormwater management programs to comply with the
Municipal NPDES permit, including inventorying the stormwater systems and construction of local
and regional Best Management Practices (BMPs). One of the major goals of this updated plan is
the integration of these documents and programs into a comprehensive Public Works management
program
Adaptive Urban Stormwater Management and Level of Service
Traditionally drainage in the Denver Metropolitan Area has been managed with a combination of
underground storm drains, overland flow conveyance elements (e.g. roads and channels) and
regional detention facilities. Currently, it is Denvers policy to require drainage systems design to
conform with the Level of Service goal of fully conveying, at a minimum, the minor or initial
storm event within pipes or channels. Minor or initial storm is defined by the Denver Drainage
Criteria as a 2-year storm event for residential properties and the 5-year storm event for commercial
and industrial districts, Runoff from storm events exceeding the minor storm up to the 100-year
storm is conveyed in streets up to 1 foot deep in the gutter or in surface drainageways. Open
channels, gulches, streams, rivers and creeks are designed to convey the 100-year storm event As
the City and County of Denver continues to densify, land values have increased resulting in higher
easement and right-of-way costs for open channels. Also, parks and other open space areas continue
to be improved to provide a more active and urban setting that limits the availability of storage for
stormwater detention. The City will continue to evaluate redevelopment areas for land acquisition
for regional detention facilities to reduce peak flows. The conveyance system must accommodate
and improve the Level of Service provided by City drainage infrastructure.
Overview of Current System Deficiencies
The Storm Drainage Master Plan evaluates the capacity of the Citys existing storm drainage system
compared to predicted storm runoff rates for the minor storm event Within a majority of the older
sections of the City and County of Denver the existing storm drains provides flood protection for
between a L and 5 year storm event. Runoff generated from larger storm events is temporarily
stored in streets and ultimately conveyed to gulches and streams via the combination of roads and
storm drains when capacity becomes available, Complaints records maintained by the City since
2000 indicate a number of locations where surface storm runoff exceeds the Citys street depth
criteria of 12-inchse of flow in the gutter and significant flooding and/or property damage have been
reported. For this Master Plan, only the most significant flooding locations have been identified,
Initial hydrologic models show that localized storage which exists within the City provides
important flood flow attenuation and, as a result, it is important to phase improvements from
downstream to upstream to avoid eliminating storage that would increase peak discharges upon
downstream existing systems.
September 2014
Existing storm drainage infrastructure was considered deficient if the minor-event flow was greater
than 100% capacity of the infrastructure, Proposed infrastructure was designed to be 80% full when
conveying the minor-event flow.
Approaches to Providing an Upgraded Drainage System
The following criteria are used to evaluate storm drainage improvements:
Maximize level of public safety and property protection
En sure compati b i 1 i ty with Blueprint Denver
Ensure compatibility with projected year 2020 land uses and needs
Minimize negative environmental impacts such as 404 Permitting, NPDES Permitting, and
other Clean Water Acts implications
Maximize opportunities for water quality enhancement
Minimize life cycle costs
Support and be compatible with current capital improvement program for drainage and other
Public Works programs
Encourage and enable development participation
Provide flexibility in phasing
Minimize drainage impacts to transportation facilities, especially intersections, and high
capacity roadway systems
Minimize construction impacts to already developed properties
Provide multi-means and multi-use facilities to the maximum extent possible, and
Provide a document that is rational and likely to foster public and political support for
drainage improvements.
Cost effective implementation of a City-wide 100-year drainage system is not practical because of
the significant capital cost of retrofit construction and limited annualized flood hazard reduction.
Consequently, a phased program is recommended that prioritizes improvements to address current
hazards while improving the minor storm system.
This Storm Drainage Master Plan identifies capital improvements based upon the hydrologic
modeling and the Level of Service goal. In many cases, meeting this goal requires upsizing an
existing pipe by one or two pipe sizes. This master plan shows the capital improvement as a basis
for evaluating, prioritizing and designing capital improvements. It is not intended in all cases to
recommend removing the existing pipe and replacement with a larger pipe. Value engineering
(beyond the scope of this Master Plan) will evaluate the condition of the existing pipe, potentially
propose a parallel pipe, determine whether additional flow can be carried in the street, identify a
new outfall and/or accept existing conditions where the cost/benefit ratio is less than one.
The proposed capital improvements, in general, are shown as complete replacement with a round
pipe with conveyance capacity for the appropriate level of service based upon existing land use.
Conflicting utilities and other constraints will necessitate drainage infrastructure equivalents such as
box culverts, elliptical pipe or open channels, The assumed slope of the proposed pipe is either the
same as an existing pipe, street grade or at 0.50%. Proposed pipe 48-inch or greater has been
profiled as part of this Master Plan update and are included in the Technical Appendices, Slopes are
chosen to avoid utility conflicts. Shallower slopes, determined during preliminary design, may
necessitate larger pipes/box culverts.
Page 4


Denver Storm Drainage Master Plan
Denvers drainage criteria require all storm pipes to be reinforced concrete pipe (RCP), Many of the
older existing drain pipes were constructed with brick or other materials such as vitrified clay pipe
(VCP). Evaluating the material or age of existing pipes is beyond the scope of this project, and
replacement is based upon capacity rather than condition. Denver maintenance forces will need to
compile a separate inventory of capital improvements based upon pipe degradation
All existing collector storm pipes must be 18-inch diameter or larger according to Denver Drainage
Criteria. (15-inch pipe is allowed only if no more than one inlet is connected to the pipe.)
Therefore, all storm pipes less than 18-inch diameter and longer than 100-feet (assumed to represent
collector pipes rather than laterals) have been queried in the GIS and shown in this capital
improvement program as replacement with new 18-inch RCP
1.2 Introduction
This publication is prepared in compliance with Denver Revised Municipal Code, Division 4, Storm
Drainage, Section 56-110 Master Drainage Plan The document incorporates the practices and
principles of Volumes I and II of the Urban Drainage and Flood Control District (UDFCD)
Drainage Criteria Manual and City and County of Denver Storm Drainage Design and Technical
Manual.
This Stonn Master Plan updates the previous publication with new information, including:
2008 LiDAR topography
Additional As-Built storm drain infrastructure data for recently constructed projects
Topographic drainage basin boundaries and thalwegs
Potential Inundation Areas
Significant flooding locations
UDFCD study recommendations
This update process includes all of the City and County of Denver, except DIA, and provides a
detailed evaluation of hydrologic conditions and conceptual-level design of drainage improvements
within the following basins:
ID OUTFALL NAME/LOCATION AREA (mi-'l FUTURE LAND USE COMPOSITE IMPERVIOUSNESS
0058-01 South Platte River Prairie Gateway 1.58 40.65%
0059-01 South Platte River Globeville Utah I unction 4.07 64.50%
0060-01 South Platte River 1-70 & Colorado Boulevard 2.14 64.42%
0060-02 South Platte River 1-70 & York 1.46 64.53%
0061-01 South Platte River 27th & Federal 2.23 56.44%
0061-02 South Platte River Highland 2.98 57.87%
0062-01 South Platte River Lower Platte Valley 2.73 74.04%
0063-01 South Platte River Central Platte Valley 2.03 73.75%
0064-01 South Platte River 1 st & Federal 0.44 64.70%
0064-02 South Platte River Valverde 2.65 61.14%
0065-01 South Platte River Ruby Hill 1.25 55.45%
0065-02 South Platte River Dartmouth 0.76 86.86%
0067-01 South Platte River College View 1.29 55.17%
September 2014
ID OUTFALL NAME/LOCATION AREA (miU FUTURE LAND USE COMPOSITE IMPERVIOUSNESS
0067-02 South Platte River West Belleview 4.21 49.65%
0067-03 No Outfall Mar st on Lake 1.06 93.76%
3501-01 Second Creek West Fork Second Creek 3.45 41.05%
3700-01 First Creek First Creek & Pena Corridor 2.23 52.09%
3700-02 First Creek First Creek Green Valley Ranch 2.12 48.92%
3700-03 First Creek First Creek Doawood & Blue Grama Tribs. 2.61 61.13%
3702-01 First Creek First Creek Tributary T" 0.91 68,56%
3900-01 Irondale Gulch Irondale Gulch Stapleton 0.22 48.00%
3900-02 Irondale Gulch Irondale Gulch East Montbello 1.91 47.55%
3900-03 Irondale Gulch Irondale Gulch Parkfield 2.93 61.83%
3900-04 Irondale Gulch Irondale Gulch Majestic Commerce Center 1.85 76.52%
3901-01 Irondale Gulch Irondale Gulch West Montbello 3.27 66.50%
3901-02 Irondale Gulch Irondale Gulch Gateway 0.97 60.25%
4000-01 Rocky Mountain Arsenal Stapleton West Section 10 0.74 34.02%
4300-03 Clear Creek Clear Creek North of 1-70 1.81 50.39%
4309-01 Clear Creek Berkeley Lake 1.83 46.59%
4400-01 Sand Creek North Stapleton 3.86 62.74%
4400-02 Sand Creek Quebec Corridor 4.41 62.55%
4400-03 Sand Creek Stapleton 1,51 66.79%
4400-04 Sand Creek East Stapleton 1.90 66.10%
4401-01 Westerly Creek Westerly Creek South Stapleton 3.01 49.09%
4401-02 Westerly Creek Westerly Creek -11th Avenue to Montview 1.06 59.36%
4401-03 Westerly Creek Westerly Creek Lowrv 3.98 41.74%
4401-04 Westerly Creek Westerly Creek South of Alameda 2.85 65.09%
4500-01 Montclair City Park 4.26 46.52%
4500-02 South Platte 36th & Downinq 1.74 56.39%
4500-03 Montclair Park Hill Colfax 1.52 52.20%
4500-04 Montclair Park Hill 6"' Avenue 3.65 45,44%
4600-01 Cherry Creek Central Business District 2.23 72.56%
4600-02 Cherry Creek Cherry Creek Mall 4.57 52.40%
4600-03 Cheriy Creek Upper Cherry Creek 5.60 65.27%
4600-04 Cheriy Creek Cherry Creek Reservoir 5.74 49,99%
4601-01 Goldsmith Gulch Lower Goldsmith Gulch 4.04 51.13%
4601-02 Goldsmith Gulch Middle Goldsmith Gulch 1.34 64.43%
4700-01 Sloan's Lake Sloan's Lake 1.58 57.88%
4800-01 Lakewood Gulch 1 2th & Federal 1.18 51.58%
4801-01 Dry Gulch 1 2th & Sheridan 0.39 62.00%
4900-01 Weir Gulch Weir Gulch 2.38 50.39%
5000-01 1-25 & South Platte West Washington Park 1.23 63.66%
5000-02 1-25 University & Mexico North 2.81 54.35%
5000-03 Florida University & Mexico South 2.29 51.24%
5100-01 Sanderson Gulch Sanderson Gulch 5.56 49.45%
5200-01 Harvard Gulch Harvard Gulch Lower Basin 0.85 54.72%
5200-02 Harvard Gulch Harvard Gulch Middle Basin 2.75 47.38%
5200-03 Harvard Gulch Harvard Gulch Upper Basin 3.84 51.11%
5300-01 West Harvard Gulch West Harvard Gulch 1.44 52.34%
5401-01 Greenwood Gulch Greenwood Gulch 0.17 73.66%
Page 5


Denver Storm Drainage Master Plan
ID OUTFALL NAME/LOCATION AREA (mb') FUTURE LAND USE COMPOSITE IMPERVIOUSNESS
5500-01 Bear Creek Bear Creek Fort Loci an 3.11 53.57%
5500-02 Bear Creek Upper Bear Creek 1.86 44.34%
5500-03 Bear Creek Academy Park 0.60 62.66%
5500-04 Bear Creek Bear Creek Marston Lake North 2,23 43.98%
5500-05 Bear Creek Pinehurst Tributary 0.71 42.08%
5501-01 Bear Creek Henry's Lake 1.36 35.03%
5901-01 Dutch Creek Coon Creek 3,10 53.67%
TOTAL 154.41
AVERAGE 56.88%
1.3 Goals of the Storm Drainage Master Plan
1.3.1 Management Interviews
To provide direction to the planning process and capitalize on the extensive experience and
knowledge of staff, selected members of the City Public Works and Planning Departments were
interviewed in 2002 and 2003, The following issues, goals, obstacles and measures for success
were identified:
Primary Drainage Issues Confronting the City
In many areas, the existing City drainage system does not meet current drainage criteria,
whereby the initial storm (2-year recurrence for residential areas and 5-year recurrence for
commercial/industria! areas) cannot be fully conveyed within pipes or dedicated drainage
channels. In other words, the current drainage system is generally undersized except for the
major drainageways, which have been improved over the years (e.g, South Platte River,
Goldsmith Gulch, Harvard Gulch),
It is impractical and prohibitively expensive to upsize the storm drain system on a City-wide
basis to provide for a 100-year storm,
The Master Plan needs to understand the implications of redevelopment. Major projects
such as Stapleton or Lowry benefited from scale economies and private-sector developer
investments to construct new improvements to outfall to major drainageways. Smaller
redevelopment projects such as those within North Cherry Creek basin or lower downtown
lack the financing and cohesion to build regional drainage systems, and
Because the existing drainage system consisting of a combination of storm drains and
surface street flow does not strictly satisfy 100-year standards, City staff must review waiver
requests on a regular basis and need a decision-making tool for evaluating the
reasonableness of proposals.
Goals for the Master Plan Update Process
Provide a regularly updated guidance document to identify storm drainage capital projects
needed to mitigate flood risks and losses
Create optimal value with the master plan to capitalize on available revenues from the
drainage enterprise fund while providing the greatest reduction in flood hazards,
Ensure that facilities are designed to be maintainable, and that a commensurate budget for
on-going maintenance and new storm drain construction is anticipated and provided for,
September 2014
Encourage the use of multi-purpose facilities such as incorporating linear parks within
riparian corridors and co-locating detention facilities within other municipally owned
properties or parks,
Provide a framework document that informs developers of potential drainage deficiencies
within project areas so that property values reflect the risk of flooding or level of capital
investment required to address stormwater management issues,
Provide a toolbox1 for reviewing development proposals, including access to background
information used in the plan and hydrologic models that may be modified by staff as more
specific development proposals are made within each, and
Provide a framework for continued urbanization of the City and County of Denver and
implementation of the concepts and tenets of Blueprint Denver: An Integrated Land Use
and Transportation Plan.
Threats or Obstacles Prey entitle Denver From Obtaining This Goal
The relatively short timeframe and broad expanse of the study area poses a major challenge
to evaluation of the basins in a street-by-street detail. Hydrologic modeling should be
developed in sufficient detail to support the conceptual design and sizing of infrastructure.
There should not be an effort to develop new technology or precisely define urban
floodplains,
Because the City has limited enterprise funds for construction of new facilities, a i 00-year
storm drain system will likely be unachievable in most drainage basins. The plan needs to
establish a rationale for appropriation of funds based upon current level of service drainage
criteria.
Appropriate Measure for Success of the Update Process
Completion of the Master Plan with enough detail to validate or justify modification of the
Citys current Capital Improvement Program (CIP),
Establishment of a framework for screening options and supporting a preferred plan for
implementation, and
Creation of a document that is usable and provides for continued update by the Citys GIS
and storm drainage master plan update processes.
1.3.2 A dditional Studies
In accordance with Denver Revised Municipal Code (DRMC) Section 56-110(c), the City and
County of Denver as a matter of course conducts additional studies as may be necessary to
determine the most cost-effective approach and the estimated costs of constructing the drainage
facilities shown on the master plan which do not presently exist.
Page 6


Denver Storm Drainage Master Plan
1.4 Plan Formulation
1.4.1 Geology
The City and County of Denver is built across the deepest part of the asymmetrical Denver basin.
Most bedrock outcrops in Denver consist of the Denver formation of Paieocene Age, although the
Arapahoe Formation of Cretaceous Age outcrops in the low areas near the South Platte River.
These two formations are similar in lithology and were deposited as a result of alluvial action,
torrential floods, and dilation in quiet lakes. Overlying the bedrock surface at most places is a
relatively thin covering of unconsolidated surficial materials composed of boulders, cobbles, gravel,
sand, silt and clay. The surficial alluvial material making up the floodplain and terraces of the South
Platte River is predominantly sand and gravel with some silt and clay beds. Geologic maps clearly
identify ancient and historic alluvial stream beds prior to these drain ageway s being filled in by
development. Figure 1 illustrates the bedrock topography for the downtown area of the South Platte
River, Cherry Creek, and Sand Creek. This map identifies a paleo-channel alignment of Cherry
Creek primarily through what now has been defined as Basin 4400-02.
1.4.2 Climate
The Lower South Platte drainage area experiences a climate commonly known as a semiarid
continental type. The area is characterized as a zone of transition from a plains to a foothills
climate. The area has cold, dry winters and cool, relatively dry summers. Typically, there are low
precipitation rates and humidity, pronounced variations in diurnal and seasonal temperatures, and
periods of high winds.
Average annual temperature is around 49 F with a recorded high on June 25, 2012 of 105 F and a
low of -30 F recorded in 1936. Diurnal temperature fluctuations usually range from 26 to 29 F
for most months; however, around July daily fluctuations can be much greater. A wide average
range in daily temperatures is typical of the high plains. Extremely hot weather in summer or
extremely cold weather in winter generally does not last long and is followed by more moderate
temperatures.
Annual precipitation averages about 15.8 inches. More than two-thirds of the precipitation falls
from April to September, which is the average annual growing season. On average, Denver
experiences about 75 storm events annually. Of these 75 events, about 46 on an average annual
basis produce less than 0.1 inch of precipitation. About 22 of the remaining 29 runoff-producing
average annual events total between 0.1 inches and 0.5 inches of precipitation. Typically, Denver
experiences only 7 large storm events (greater than 0.5 inches) annually. These significant storm
events are characterized by short duration, high-intensity rain showers that overwhelm the existing
drainage system for several hours.
September 2014
mtfm l



Figure 1: Geohydrology Map (Robinson 1996) of Downtown
Denver showing bedrock contours and evidence of historic
channel alignments. The map shows Cherry Creek once flowed
through Basin 4400-02 between Quebec and Colorado Boulevard,
; ,Vrfjrf Approldmeu align menldf principal
wUejfc in bedrock urine*'-
Une pattern fndtatei pateovaley,
BfdroefcjarfKf contour
Stowf approximate altitude
ol bedrock surface underlying
oncoititildflted nR
Dashed harf btfrmd.
Hachurei Indicate depression
tatim Contour bitetval
20 feel Index contour
interval 100 feel Datum
issea level
* A' Una trf genktolc ucikn
Page 7


Denver Storm Drainage Master Plan
The driest months are December through January Average annual snowfall at Denver is about 59
inches. Humidity averages about 39% during the day and 62% during the night. Humidity is
slightly higher in winter than in summer. The sun shines approximately 69% of the possible
sunlight hours annually.
Wind speed averages about 5.9 mph, and upslope winds predominate from the south and west An
average wind speed is not adequate to describe conditions in the area. Low wind conditions have
been experienced and often contribute to air pollution problems. High velocity winds often destroy
trees, crops, and structures, and winds in excess of 90 mph have been recorded
1.4.3 Topography
The South Platte River Drainage Basin can be divided into a plains region and a mountain region.
The plains exhibit a trellis drainage pattern; streams flowing in alluvial channels. The mountain
regions are characterized by a dendritic drainage pattern.
The Lower South Platte drainage area topography represents flat to gentle undulating plains with
elevations ranging from 5,650 feet in the southeast to 4,950 feet in the floodplain of the South Platte
River. Drainage from the west flows easterly from the foothills into tributaries of the South Platte
River On the east side of the South Platte River in the Denver area, major drainage flows lead from
southeast to northwest by way of Cherry Creek, Sand Creek and Harvard Gulch.
1.4.4 Flood History
The City and County of Denver and surrounding metropolitan areas lie within the watershed of the
South Platte River. Development has occurred within the geomorphic floodplain and has taken
place in areas previously devoted to gardening and farming. Residential areas within the historic
floodplain include Globeville, Valverde and scattered smaller developmental areas.
Numerous flood control and mitigation measures have been implemented throughout the years to
reduce the flood hazards. In 1901 Mayor Speer suggested constructing walls along Cherry Creek,
the first ordinance was passed in 1908, and construction was completed in November 1915. A
Cherry Creek Flood Commission was appointed in 1912 and recommended a dam with reservoir
capacity of 12,000 acre-feet. However, the Castlewood Dam built on Cherry Creek in 1890 failed in
August 1933 After the 1933 flood, City officials decided to build a flood control dam at Kenwood.
Also during this time, Works Progress Administration (WPA) workers straightened and riprapped
the Cherry Creek banks. In 1950, the U.S. Army Corps of Engineers completed Cherry Creek Dam
1,000 feet upstream from Kenwood Dam.
June 1965 was a notable period of severe flooding around Denver. Following the flood, several
steps were taken to mitigate the effects of flooding from such an event. Congressional support was
sought to build Chatfield Dam as a flood control structure for the South Platte River, The Mayor of
Denver constituted a South Platte River Development study group to develop a plan for the Platte
River Valley that would incorporate various flood control measures. Several private groups in the
community organized themselves to provide support for the planning effort. The preliminary report
for Chatfield Dam was issued in December of 1965 and construction was completed in 1973.
The following is a summary of the major storm and flood events in the Denver metro area:
September 2014
May-June 1844 The earliest flood for which circumstantial evidence is available occurred in
1844. The bottomlands in the vicinity of Denver were covered in water extending from the bluff
on Cherry Creek to the extreme bluff on the South Platte River according to Major James Bridger
in a June 22, 1864 article in the Denver Commonwealth,
May 19-20, 1864 Heavy rain over the upper basin of Cherry Creek caused 19 deaths along Cherry
Creek and the South Platte River in Denver, The flood from May 18 combined with this flood and
covered the lower sections of the City with 1 to 5 feet of water. The flood washed out several
bridges and swept large buildings off their foundations. Property damage from the flood was
estimated at approximately one million dollars,
July 14,1912 A thunderstorm with heavy rain in the late afternoon combined with a similar storm
south of the City to produce widespread flooding on Cherry Creek in downtown Denver and
resulted in two deaths. The flooding in Denver was the worst since 1864 and covered
approximately 3 square miles of lower downtown. Bridges along Cherry Creek were washed out
and water lapped at the floor of the Broadway Bridge over the South Platte. The flood water caused
great damage to the drainage system, parkways, bridges and to residences and commercial
warehouses near Cherry Creek. Flood damage was estimated at several million dollars.
May 21, 1914 A severe thunderstorm produced heavy rainfall of 0.83 inches in 15 minutes.
Flooding caused considerable damage to bottomlands in eastern and southern parts of Denver.
June 2-7,1921 During April the snowfall had been unusually heavy, approximately three times its
normal depth for that month. Rainfall measurements in the foothills ranged from 3 to 5.5 inches
from June 2 through 7. The South Platte River in the canyon reached a stage of 9 feet and washed
out the tracks of the Colorado and Southern Railroad. The bottomlands in the valley below Denver
were flooded, with the overflow being as much as 4 miles wide near Sterling. The overflow
reportedly stretched the 43 miles from the mouth of the canyon to Denver
August 2-3, 1933 3 to 9 inches of rain in 9 hours caused Castlewood Dam on Cherry Creek to fail.
Seven people died in Denver. Damage was estimated at 1 million dollars.
September 10, 1933 A cloudburst occurred over the South Platte River between Denver and the
foothills, with the center over Plum Creek, Little Dry and Big Dry Creek basins. Although
information on tributary flows is limited, it was estimated that the Plum Creek discharge
downstream from the confluence of the East and West branches was about 30,000 cubic feet per
second attenuating to about 5,500 cubic feet per second at the mouth, On Cherry Creek a peak
value of about 15,000 cubic feet per second was estimated to have occurred near the mouth while
upstream near the site of the Cherry Creek Dam, a peak of 34,000 cubic feet per second was
estimated, The peak values on Cherry Creek were partially the result of failure of a small dam
located in the upper reaches of the basin On the South Platte at the U.S.G.S. stream gaging station
at Denver, the peak discharge was 22,000 cubic feet per second, which was the largest flood on
record prior to the 1965 event (gaging station established in 1895).
May 1942 Heavy rains caused extensive damages along the South Platte River. The high water
destroyed five bridges including those at West Evans and West Mississippi.
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Denver Storm Drainage Master Plan
August 2-3,1951 Almost VA inches of rain fell on the Denver Metro area.
July 9, 1953 Heavy rains caused estimated 2 million dollars damage from flooded stores and
basements across metro Denver, The floodwaters reached a depth of 3 feet on streets in some
sections of the City, damaging streets and automobiles. The heavy rainfall at Lowry Air Force Base
totaled 3.9 inches.
July 30-August 3, 1956 Up to 12-inches of rain fell in five days in the Denver area and on the
western slope, causing $5 million in damage.
June 16, 1965 Black Wednesday, the day Denver was hit by the worst natural disaster in the City's
history. After a cloudburst that dumped i 5 inches of water on mountain slopes southwest of
Denver, a devastating flood struck 20 counties, including Denver along the South Platte River.
Twenty-five people were killed, and property damage was estimated at more than $500 million.
Since that time, Chatfield and Bear Creek Dams have been constructed greatly reducing the flood
threat to Denver from precipitation over major sub-drainage basins.
July 23, 1965 Heavy rains in Aurora washed out earthen bridges over Sand Creek. Several
highways were washed out to the east and southeast of Denver.
July 24, 1965 Heavy rain fell over all of the Denver and Aurora areas, causing some flooding of
roads, streets, and bridges.
July 7, 1967-A storm caused flood damage in southwest and south Denver. Unofficial reports
indicated rainfall of 2 inches in 30 minutes and more than 3 inches total from the storm. Streets and
buildings were flooded by the heavy runoff. Hail in some areas contributed to flooding by blocking
storm drains, Water reached a depth of 5 feet in the street. Police rescued numerous stranded
motorists. In southwest metro Denver, 100 to 150 homes were flooded, and there was one fatality.
May 4-12, 1969 Heavy rains caused flooding on the South Platte River in Denver,
June 8, 1969 Heavy rain flooded streets and underpasses throughout metro Denver The heaviest
amounts of rain fell in south Denver and Englewood, where unofficial totals of 5 to 6 inches were
reported. Mud, debris, and hail carried by the heavy runoff clogged drains and increased the amount
of flooding. Approximately 40 cars and a large truck were inundated at an underpass on 1-25, and
several more were inundated or buried in mud in other areas A large number of basements were
flooded and streets and highways were heavily damaged in some areas.
June 11, 1970 Over 3 inches of heavy rain flooded streets and underpasses throughout metro
Denver.
May 5-18, 1973 Prolonged rains of up to 6 inches on May 5,l] and 61'1 in the South Platte Basin,
along with melting of a large snow pack, produced major flooding during the next two weeks along
Clear Creek, Sand Creek, and the South Platte River in the Denver metro area. One person died and
damages were estimated at around 120 million dollars.
September 2014
July 20, 1975 Heavy rains caused flash flooding across metro Denver, resulting in the closing of
several streets and damage to numerous homes and businesses,
June 13, 1984 One of the worst hailstorms ever experienced in metro Denver occurred, Torrential
rains with as much as 4.75 inches in Lakewood clogged drains and caused widespread damage from
flooding. There was one fatality.
May 16-17, 1995 Significant moisture and upslope flow caused flooding across metro Denver.
Moderate to heavy rains which began on the evening of the I6lh developed in the foothills and
spread eastward over metro Denver throughout the night After the spring floodwaters receded, the
Colorado Water Conservation Board (CWCB) and the Colorado Office of Emergency Management
reported i 5 flood-related deaths statewide and damage estimates approached $20 million.
June 4, 1995 The heaviest measured rainfall was from a gauge operated by the Pinehurst Golf and
Country Club located in southwest Denver where a reported 3.2 inches fell in less than one hour
Residential flooding and storm drainage problems were reported along a small south-bank tributary
to Bear Creek. The June 41'1 storm also caused flood problems in other parts of Denver, Englewood
and Sheridan. This single thunderstorm produced the highest peak flows for the year along lower
Bear Creek and the South Platte River through Denver,
July 19, 1997 At approximately 4:00 p.m., a severe thunderstorm in NE Denver and NW Aurora
produced 3.83 inches of rain in less than an hour, exceeding the official Denver one-hour record of
2.2 inches set on August 13, 1921. This storm was accompanied by copious amounts of hail with
stone diameters reaching 1,25 inches. Westerly Creek, a tributary to Sand Creek that enters the old
Stapleton International Airport property from the south, flowed out of its banks and nearly
overtopped Montview Boulevard, The Montview culverts are designed to safely pass a 10-year
flood, a project completed by Denver, Aurora and UDFCD in 1980
July 27, 1997 Between 3:00 and 4:00 p.m., Goldsmith Gulch in Denver was hit by heavy rains
with 1.66 inches falling at the Denver Tech Center (DTC). Downstream floodwaters approached
10-year levels causing the recently completed side-channel detention facility near 11 iff Avenue to
function. This flood control facility, constructed by Denver and UDFCD in 1996 was credited with
preventing damages downstream. Local residents were pleased with its performance. A minor
glitch did occur, however, when the pump that drains the facility failed to start. Denver Wastewater
Management Division officials corrected the problem the next day.
The Eastman Avenue ALERT gage peaked at 4 p.m. at a depth of 7.4 feet with an estimated
discharge of 1,670 cfs, exceeding its prior record of 1,470 cfs (8/2/9!). The Temple Pond gage at
the DTC had a maximum water depth of 8.2 feet and a peak outflow of 470 cfs
Page 9


Denver Storm Drainage Master Plan
I tiff Stormwater Detention Basin on Goldsmith Gulch
July 28, 1997 Some significant flooding occurred in Denver with Goldsmith Gulch being hit hard
for the second consecutive day, exceeding the prior days peak at Eastman Avenue by one foot and
setting a new record of 2,040 cfs at 6:30 p in, Upstream at Temple Pond, Goldsmith floodwaters
pooled to a depth of 9,5 feet releasing 500 cfs. Downstream of Eastman at Yale Avenue the peak
flow was estimated at 1,850 cfs and classified as a 10-year event. According to the Goldsmith
Gulch design hydrology model, the discharge at Eastman approached the 50-year mark. As with the
previous days storm, the 11 iff detention facility and improved channel reaches performed as
designed, preventing significant damages. By 9:00 p.m., Goldsmith Gulch floodwaters had
combined with Cherry Creek flows causing the Market Street gage in lower downtown Denver to
measure its new record peak of 3,200 cfs. The Cherry Creek gage at Steele Street also set a new
record at 2,350 cfs. Heavy rains in other parts of Denver and Aurora caused localized flooding of
many roads, parking lots and basements.
July 29, 1997 Late evening rainfall on July 28 caused the Sand Creek ALERT gage to measure a
new record flow of 4,200 cfs at 2:47 a.m. (see July 19 discussion). At Sand Creek Park near its
crossing with 1-225, the pedestrian trail crossing was overtopped by 4.4 feet, and the discharge was
September 2014
estimated at 3,480 cfs, another ALERT gage record, A parking lot flooded at Quebec Street and
Leetsdale Drive in Denver to the point that a car was found floating in it.
August 11, 1997 Hail depths of up to 2 feet, driving rains and high winds caused an estimated
$150-mil!ion in damage in Lakewood and Denver. A rainfall amount of 1 inch in 10-minutes was
measured by the Cherry Creek gage in downtown Denver, and after the hail melted, the total
measured precipitation exceeded 2 inches. Cherry Creek flowed wall-to-wall at a depth of
approximately 5 feet with a peak discharge of 2,640 cfs. This was the second highest measurement
for Cherry Creek for the year, exceeded only by the July 28 event.
September 4, 1997 Cherry Creek flowed wall-to-wall. Five rain gages had alarmed (1 inch in less
than 1-hour) by 9:45 p.m. The locations and amounts were accurately reported to the public at the
start of the 10 p.m. broadcast.
July 25, 1998 Heavy rains that occurred during the evening caused problems in Denver with
flooded basements, stranded drivers and downed power lines. A forecaster for the NWS measured 3
inches in 30 minutes at his home near W. 38th Avenue and Federal Boulevard The railroad viaduct
near 38th and Fox (Basin 0061-01) trapped motorists in water 4 to 5 feet deep. This notorious flood
area has been less of a problem in recent years due to drainage improvements completed by Denver
and UDFCD, but this storm clearly exceeded the design rainfall amounts.
July JO, 1998 Denver streets flooded, zodiac boats were needed for rescues at "Lake Logan"
(Logan Street underpass of 1-25) and a kayaker was rescued from the South Platte at Santa Fe,
July 31,1998 A flash flood watch was issued by the NWS shortly after 2 p.m. for the entire Front
Range from Colorado Springs to Fort Collins. In Denver, street flooding damaged private property
in the vicinity of Evans Avenue and Lipan Street.
April 29-May 1, 1999 On April 30 and May 1, the NWS issued flood watches for the South Platte
River and other large Denver area streams. Gradual rises in river stage were observed due to
relatively high rainfall accumulations over the prior week, Englewood Dam recorded a record high
water depth of 16.2 feet on April 30, Spillway flows begin at a depth of 40 feet. Flood control
improvements to this District-owned, normally dry detention dam were completed in 1976.
July 31, 1999 Martin Luther King Boulevard in the Park Hill area of Denver was barricaded due to
flooding between Colorado Boulevard and Quebec Street. However, this measure did not stop six
motorists from driving into the flooded area and stalling. Sand Creek recorded its annual peak while
the Havana Park detention facility in the Westerly Creek basin overflowed into neighborhood
streets, Thunderstorm rain in Denver and Aurora exceeded one inch at 8 gaging stations with 1.69
inches occurring at Horseshoe Park in Aurora.
August 10, 1999 In the Denver area, more than 3 inches were reported to have fallen in less than
an hour. The highest ALERT rain measurement was 2.52 inches, near 1-225 and Sand Creek in
Aurora. In addition to the wind and rain, hail and lightning caused problems for many areas
including DIA.
Page 10


Denver Storm Drainage Master Plan
August 17,2000 Denver Fire Fighter, Bob Crump, died in the line of duty after rescuing a woman
from floodwaters in the vicinity of E. 49th Avenue and Colorado Boulevard (Basin 0060-01). Mr.
Crump lost his life after being pulled into a submerged open 36 inches stormdrain. The storm at this
location was estimated to be a 75-year event. The flooding that was realized this day was somewhat
unexpected. Morning analysis indicated minimum flood potential, but weather conditions changed
substantially by mid-afternoon. Within 10 to 15 minutes, heavy rainfall was occurring over
northern Douglas County and the Littleton area. By 4 p.m,, the NWS had issued an urban and small
stream flood advisory for this storm and at 4:37 p.m. the advisory was upgraded to a flash flood
wanting for a large portion of the Denver metropolitan area.
May 3-5, 2001 Three days of steady upslope rain saturated soils along the Front Range. Rainfall
amounts totaled 2 to 3 inches over much of Denver causing some minor street flooding while larger
streams like Cherry Creek and the South Platte River rose above normal. Two reservoirs monitored
by the ALERT system recorded their annual peaks on May 5.
June 20, 2001 At 7:20 p.m., heavy rain and damaging hail struck DIA causing major damage.
Between 40 and 50 mobile homes were also damaged in the Watkins area.
July 8, 2001 Serious street and stream flooding hit Denver between 4 and 6 p.m. The storms were
accompanied by high winds and small hail, Flash flooding was observed on Harvard Gulch,
Goldsmith Gulch, Cherry Creek, the South Platte River, and along 1-25 where the infamous "Lake
Logan" (Logan Street/I-25 underpass) once again stopped traffic. The Harvard Gulch at Jackson
Street rain gage measured the heaviest rainfall of 0.67 inches in 5 minutes and 2,48 inches in an
hour
Goldsmith Gulch upstream of Mexico Avenue on.July 8, 2001.
July 23, 2001 A highly localized storm impacted rush hour traffic around the Denver Tech Center.
Hail, wind and rainfall amounts exceeding 1.2 inches in 30 minutes slowed travel on 1-25 and 1-225.
Funnel clouds were also reported. The South Platte River gage at Union Avenue recorded its record
flow for the year.
September 2014
August 5, 2002 A heavy thunderstorm near DIA set a record high water level for the 2-year-old
ALERT stream gage on Third Creek, The rain gage at that station measured 2,36 inches and
prompted the NWS to issue a flash flood warning. Most of the metro area received less than an inch
of rain while two gages in the Bear Creek basin measured over an inch.
September 13, 2002 Once again the I-25/Logan Street underpass was inundated by stormwater -
this time disrupting traffic for over 3 hours during evening rush hour. A number of motorists were
rescued from their vehicles. Rainfall totals 1.06 inches to 1.18 inches were measured near the 1-25
corridor between the Denver Tech Center and Broadway. The Transportation Expansion Project (T-
REX) construction vastly improved this historic drainage problem,
August 18, 2004 It was a deluge that produced standing water across the entire region and an
average of 1.62 inches of precipitation fell on Denver. The South Platte River swelled to 10,000 cfs
from 300 cfs earlier in the day. The Denver Fire Department responded to nearly 180 calls between
4:30 and 6:30 pm, 10 times the normal volume. Many of those calls requested water rescues, City
and State crews used snowplows to clear water from clogged drains in Denver. About 5 inches fell
on the Denver Zoo. A car was swept over a 6-foot embankment about 1:00 ant, Two lanes of
northbound 1-25 at West Alameda Avenue were closed under 8 inches of standing water. The worst
flooding spots were: 1-25 at Alameda and 1-70 in the area of Vasquez, Steele and York streets,
Manna Pro grain elevators at 44th and Madison, and the Union Pacific Railroad bed was washed out
at the BNSF crossing between Madison and Monroe Streets leaving 100 of track hanging in midair
June 3, 2005 A heavy thunderstorm swept through southeast Denver flooding 9 homes in the
Hamden Heights neighborhood to varying degrees as well as flooding East Girard west of Havana,
damaging numerous parked cars, This storm was estimated to be between a 50 and 100-year rainfall
event. Surcharging on storm drain manholes in Five Points was recorded.
Flooding on E Eastman A venue on June 3, 2005.
Page 11


Denver Storm Drainage Master Plan
July 4,2006 Independence Day was a weather-producer in 2006 with nature contributing its own
fireworks. Denver and Arvada were the primary targets for heavy rainfall with many gages
reporting more than an inch of rain. The Cherry Creek gage at Steele Street measured the greatest
amount of 1.73 inches. The rainfall did not, however, prevent the anticipated celebrations from
taking place. Five stream gages recorded annual peaks
August 13,2006 Multiple storms occurred during the evening hours causing the ALERT system to
generate 11 rainfall alarms from 7 stations in Denver, Aurora and Golden between 8:15 and 10:40
pm. Annual peaks occurred at 8 stream gages on Harvard Gulch, Goldsmith Gulch, Westerly Creek
and the South Platte River This was a busy day for the ALERT system, but fortunately, no major
damages were reportedjust some nuisance flooding during the late evening. Consequently, this
event attracted little media attention.
August 14, 2006 Heavy rainfall was recorded in the Capitol Hill area, causing flooding on East
Colfax at Clarkson, Williams and Colorado Boulevard. Businesses and subterranean condominiums
along 17111 Avenue from Lafayette to Humboldt were also flooded.
August 19,2006 Northwest Denver experienced an intense localized storm cell resulting in
flooding at the W. 3811' Avenue underpass of the railroad tracks between Inca and Fox,
IVlay 14,2007 A thunderstorm developed rapidly due to multiple thunderstorm outflow boundaries
that were initiated by weak and moderate thunderstorms across western Jefferson and western
Boulder Counties The thunderstorm produced heavy rainfall of 0 75-inch to 1.50-inch in 10-30
minutes across eastern Jefferson, Denver, western Arapahoe and southwest Adams Counties. Short
lead Red Flood Alerts were issued for these 4 counties. Two-year-old Jose Matthew Jauregui Jr.
was swept away by rapidly rising water along a bike path in Lakewood Gulch at Decatur Street, His
body was later recovered downstream in the South Platte River.
Flooding in southern Denver on July 27, 2007.
(Photo Courtesy Denver Post)
July 27, 2007 A Flash Flood Watch was issued for the entire Denver area due to the threat of very
heavy rainfall that could initiate flash flooding and urban flooding. Strong thunderstorms developed
late in the afternoon across the southern portion of Denver. The storms moved very slowly to the
September 2014
north producing heavy rainfall of 1.50-inches to 2.50-inches in 30-60 minutes prompting a Flash
Flood Warning for Denver, Arapahoe and Adams Counties,
August 8, 2008 A severe thunderstorm cell moved through central, east central and southeast
Denver causing flooding in the Country Club neighborhood, Cherry Creek North, Hale Parkway,
Severn Place between Jersey and Jasmine, S. Holly and Pacific Place and E. Mississippi and
Leetsdale/Parker Road. In some areas 2-inch to 2,5-inch of rain was recorded in a 1 hour period
equivalent to a 100-year storm. Several homes, business and apartments were flooded in each of
these areas.
April 16-18, 2009 A big precipitation event arrived by way of a winter storm. Many streams
were flowing well above normal and four stormwater detention basins recorded annual peaks,
including Kelly Road Dam in Denver Denver Fire Department rescued at least one person that
became trapped between the channel walls of Cherry Creek.
May 24-25, 2009 Heavy intense rain dropped 2-inch plus rains over central Denver, Minor
flooding occurred along Lakewood Gulch through Denver, with a peak flow of 600 cfs at 10th
Avenue
June 23-25,2009 This storm impacted DIA and caused street flooding during rush-hour with hail
that hit the northwest metro area. These storms produced strong east moving thunderstorms over
Denver that caused a downpour of 1.5 to 2,4 inches in 20-45 minutes and prompted a NWS flash
flood warning in this 3-day period. Four east Denver condominiums were flooded by 4 feet of
water and a dog died at 5300 East Cherry Creek Drive South, Several homes flooded along East
Missouri Avenue and the sump at East Tennessee Avenue and Oneida Street flooded Rainfall totals
exceeded 2 inches at some locations.
July 3, 2009 This day was the second in a 5-day series of stormy days. The National Weather
Service reported that severe thunderstorms produced large hail north and east of Denver. Localized
flooding was reported in central and southeast Denver including S. Glencoe south of E Yale
Avenue
Flooding on Howard Gulch on July 3, 2009.
(Photo Courtesy Ed Done)
Page 12


Denver Storm Drainage Master Plan
July 10, 2009 Storms triggered many rainfall rate alarms between 8:30 and 10 p.m. in Denver,
causing some minor street flooding and flooded several properties in central and east Denver,
July 20, 2009 A supercell thunderstorm moved quickly to the south producing very intense
rainfall, large hail and powerful straight line winds. Property damages from the wind and hail were
high, and localized flooding was reported in east Denver, The storm duration was short but the
rainfall intensities were very high.
April 21-23, 2010 A system of strong thunderstorms produced large hail and heavy rainfall. The
stormy period lasted about 48 hours, changing over to a widespread rain and snow storm with
precipitation totals exceeding 2 inches at many locations. Runoff from the storms caused annual
flood peaks affecting Kelly Road Dam on Westerly Creek in Denver, and Sand Creek and Cherry
Creek through Denver. No serious damages occurred; however, this storm caused the largest
widespread flooding event of the 2010 flood season,
August 4, 2010 Heavy rains impacted Westerly Creek in Denver. Annual flood peaks were
recorded in this drainage basin. While rainfall totals only approached 1.4 inches in this area,
stations measured very high intensities.
July 7,2011- This was the biggest rain day of 2011. Rainstorms appeared with flash flood and
severe thunderstorm warnings being issued for Denver County. The heaviest total rainfall occurred
in the area bounded between Alameda Avenue and 1-70 from 1-25 on the west to 1-225 on the east.
The largest storm totals exceeded 3 inches in the Westerly Creek basin located in Denver. Denver
officials reported that storm sewer manholes popped their covers at over 50 locations. Numerous
streets, intersections and underpasses were flooded, and dozens of properties reported flood damage
across a wide swath in central and east Denver, Ferril Lake as City Park which had been modified
in 2007-2008 to provide stormwater detention rose nearly 3 feet during the storm as intended.
Annual peak flows were recorded for Westerly Creek in Denver,
Total Rainfall on July 7, 2011. Reel Shades Indicate 2- and 3-Inches of Total Precipitation.
(Courtesy of NOAA)
September 2014
July 12,2011 Annual peaks were measured in Denver on Cheriy Creek, Lakewood Gulch,
Sanderson Gulch, and the South Platte River. The Sanderson Gulch and Lakewood Gulch stream
gages set new records. Rain totals were mostly less than 2 inches.
July 13, 2011 Storms caused an annual stream flow peak on Goldsmith Gulch in Denver. Damage
was reported at the Boys and Girls Club in Denvers Westwood neighborhood and flooding was
reported at one home in west Denver.
July 14, 2011 Heavy rainfall occurred to the west in Denver County where annual peaks were
recorded for Harvard Gulch and Goldsmith Gulch at Uiff Avenue in Denver. Flooding was reported
again in Glencoe Street south of Yale Avenue.
July 7, 2012 A late evening storm arrived the evening before and remained until the morning of
July 7, affecting Denver County,
September 12, 2012 Denver was issued a special Cherry Creek Trail Flood Advisory for low
impact flooding due to a general wide-spread low-intensity rainfall over the region.
July 13, 2013 Multiple thunderstorms moved through Denver during afternoon hours with rainfall
totals exceeding 3 inches. The storm caused Lakewood Gulch in Denver to rise over 6 feet in a
short period setting a new record for the USGS gage that has operated continuously since 1981.
Localized flooding was reported at Martin Luther King Boulevard and Eudora Street.
September 9-15,2013 Waves of rainfall during mid-September caused significant flooding and
related damage outside of Denver, especially in Aurora, Commerce City, Boulder, Jamestown,
Lyons and Estes Park, Denver experienced significant rainfall and peak flows, Rainfall intensities
exceeded 3 inches per hour for periods of time on September 9, 10, 12, and 15. Overall, total
precipitation exceeded 12 inches in some parts of Denver. More than 5 inches fell over the
Westerly Creek basin and activated the spillway at Kelly Road Dam at Ell"1 Avenue & S Willow
Street. Floodwaters on Sand Creek caused considerable bank erosion that threatened the Metro
Wastewater Treatment Plant near its confluence with the South Platte River.
Page 13


Denver Storm Drainage Master Plan
/. 4.5 Existing Conditions
The associated Technical Appendix notebooks are organized by basin and include all CUHP and
SWMM hydrologic and FLO-2D models- Existing drainage conditions have been evaluated through
field reconnaissance, research of complaint records, and detailed hydrologic modeling using the
Colorado Urban Hydrograph Procedure (CUHP 2000) and Urban Drainage Stormwater
Management Model (UD-SWMM) software developed by UDFCD, Modeling of the fully
urbanized basins within the City and County of Denver poses a significant challenge because of the
high degree of impervious area and complex basin routing inherent in the system. To ensure that a
reasonable model was developed to simulate these conditions, there has been extensive coordination
among the consultant team, City and County of Denver staff, and UDFCD The participation of this
team of experts has resulted in the development of sophisticated models which are linked with GIS-
based capital budgeting tools. This approach will enable the models to be incorporated in
subsequent versions of CUHP and UDSWM, including the incorporation of future GIS
advancements.
Parameters for Stornnvater Runoff
Volume l of the UDFCD Storm Drainage Criteria Manual provides the basis for input data for
CUHP. In order to more accurately simulate the potential for runoff under future conditions, the
Denver GIS database has been used to evaluate existing land uses and densities within commercial
and residential areas. These have been compared with the permitted densities (and corresponding
imperviousness) for current zoning and have been overlain with Blueprint Denver to ensure that a
reasonable upper limit is used Generally, the imperviousness for residential areas was set at 52%,
commercial/retail from 80 to 90% and industrial 90 to 95%,
One-hour rainfall depths for the CUHP model were obtained from the Urban Storm Drainage
Criteria Manual, Volume 1 for the following recurrence intervals:
2-year 0.95 inches
5-year 1.34 inches
100-year 2.57 inches
Evaluation of Split Flow Conditions
Hydrologic modeling of drainage conditions within Denver is further complicated by split flow
conditions in major storm events, whereby the direction of storm drains contravenes the surface
gradient. Many of the existing storm drain systems have little more than 1-year capacity, and will
have 2 to 5-year capacity under proposed improvement conditions Delineation of the basins is
important to ensure proper sizing of proposed improvements and also to evaluate overland flood
flow conditions. As a result, two models have been developed: 1) a low flow model for the minor
storm event, and 2) a split flow model which extracts the low flow and accounts for trans-basin
diversions of flow to enable mapping of potential hazard areas under 100-year storm event
conditions. Potential inundation areas are shown as shaded zones on the full-size work maps (see
Technical Appendices or GIS database) to facilitate planning staff review of development
applications and to advise potential landowners or developers of inherent localized Hood hazards.
These are areas where ponding or flow depths could exceed 18-inch; however, they have not been
mapped using regulatory criteria or modeling techniques and are therefore considered only a rough
guide of potential inundation.
September 2014
1,4.6 Future Development
The Denver Storm Drainage Master Plan is one of several documents that will feed information into
the Citys Comprehensive Plan Blueprint Denver is another essential framework document that
both identifies major transportation network improvements and establishes the basis for future land
use planning. To assist with future planning, Areas of Change and Areas of Stability have been
delineated in Blueprint Denver. The Areas of Change map is included for reference to show the
potential for changing hydrology and highlight the areas where capital investment in infrastructure
is expected,
2.0 MAJOR DRAINAGEWAYS
The following is a description of each of the major drainageways within the City and County of
Denver, beginning furthest downstream and continuing upstream.
2.1 South Platte River (Basin 0000)
The South Platte River is the largest receiving waterway in the Denver Metropolitan area and flows
from south to north along the 1-25 corridor through the City and County of Denver. Within the City
limits of Denver, the South Platte River meanders along a path some 11.7 miles in length from
Dartmouth Avenue to Franklin Street The drainage basin covers approximately 4,850 square miles
extending from the Continental Divide in the Rocky Mountain Front Range to the high plains and
foothills of eastern Colorado. The mountainous portion of this basin is generally unsuited for dense
development, while the foothills and high plains areas are actively being developed. The intense
urbanization in the metropolitan area consists primarily of residential and commercial areas and
some industrial regions along the river valley.
The South Platte River flood potential is mitigated by Chatfield Reservoir (constructed in 1973 )
located on the South Platte River, along with Cherry Creek Reservoir (constructed 1950) and Bear
Creek Reservoir (constructed 1977) located on major tributaries. Short duration flooding will
continue to occur from extremely heavy precipitation in those areas below the dam-sites. Peak 00-
year flows of the South Platte vary from 5,000 cfs near Chatfield to 38,000 cfs at the confluence
with Sand Creek. Dry weather discharges in the South Platte River through Denver generally range
from 150 cfs upward to over 1,000 cfs during the spring runoff period. Average daily flows
downstream of Denver are highly affected by treated effluent discharges from the Metro Wastewater
Reclamation District treatment plant
2.2 Second Creek (Basin 3500)
Second Creek drains about 27 square miles of area to the South Platte River. The basin is about 15
miles long and 3,4 miles wide at its widest point. The drainage basin ranges in elevation from 4,
990 at the South Platte River to 5,650 feet at the basin divide. Second Creek has a natural irregular
channel section in the upper reaches above the OBrian Canal. The Second Creek Basin is crossed
by US Hwy 85, U-76, the Union Pacific and Burlington Northern Railroads, the OBrian Canal,
Fulton Ditch and the Burlington Ditch. Second Creek has a natural irregular channel section above
the OBrian Canal and a small, poorly defined channel section between the OBrian Canal and the
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Denver Storm Drainage Master Plan
South Platte River. Existing development within the Second Creek basin is mainly agricultural,
with irrigated farmland located in the South Platte River Valley and dryland farming and pasture in
the upstream areas.
The southern land area of the Second Creek drainage basin within the Denver city limits drains via a
tributary known as the West Fork of Second Creek. This tributary drains about 3 square miles of
area to Second Creek. The High Line Canal terminates at the West Fork. The sustained unused
flow in the High Line Canal has been wasted to the West Fork downstream of 64llj Avenue, and the
flows have eroded the channel on the West Fork. At Tower Road, the West Fork channel is about
15 feet deep with vertical and very steep, unstable banks. The confluence of Second Creek and the
West Fork of Second Creek is a wide, relatively flat area supporting a stand of cottonwood trees.
Some wetland areas are present in the upper reaches of the West Fork, but, as the channel has
eroded, the channel banks have become incised and support only a narrow band of wetland or
riparian vegetation. The floodplain is contained within the channel except at road crossings, where
overtopping may occur. The banks are unstable and some lateral channel migration may occur
during large flows.
2.3 First Creek (Basin 3700)
The First Creek basin drains an area of 47.2 square miles. The headwaters of First Creek are located
in Arapahoe County, south of 1-70 and east of E-470. Runoff from the basin flows in a
northwesterly direction, First Creek crosses Pena Boulevard just north of SO1'1 Avenue and flows
through the northeastern portion of the Rocky Mountain Arsenal. First Creek is an east bank
tributary to the South Platte River, and outfalls at approximately 128th Avenue, The basin shape is
long and narrow, approximately 26 miles long and 2 to 4 miles wide. The average stream slope
above Rocky Mountain Arsenal is about 31 feet per mile, and flattens to about 23 feet per mile
below Rocky Mountain Arsenal
The upper reaches of First Creek are primarily undeveloped irrigated cropland with wide swales and
channels for drainageways, Toward the center of the basin, First Creek bisects Green Valley Ranch,
which consists of medium density, single-family residences. First Creek then enters Rocky
Mountain Arsenal with a more incised, low flow channel and wider floodplain areas.
The lower First Creek basin is located downstream from 5611 Avenue and Pena Boulevard and
continues to the South Platte River. The lower First Creek basin consists of irrigated farmland with
pockets of light industrial and residential properties. Conveyance within the lower First Creek
drainage consists of broad undefined channels with little or no defined thalweg. Between US-85
and Brighton Boulevard, the channel is incised with a well-defined thalweg The OBrian Canal and
the Burlington Ditch which intercept runoff in First Creek cross the reach of First Creek below
Rocky Mountain Arsenal
2.4 Irondale Gulch (Basin 3900)
lrondale Gulch, which contains approximately 26.7 square miles, lies immediately southwest of
First Creek and drains the general area near the intersection of 1-70 and Picadilly Road and the
September 20/4
Adams County line, through the Montbello area, the Arsenal and Commerce City with an eventual
outfall to the South Platte River at approximately East 96Ul Avenue The southwest boundary of the
basin is primarily the north side of 1-70 until reaching the former Stapleton International Airport,
where the basin boundary lies just west of Havana Street. This basin is long and narrow, with a total
length of 28 miles to the South Platte River and VA to 2 miles wide. The average slope of the basin
is about 26 feet per mile, which remains fairly constant throughout the drainageway The
drainageways through the Arsenal contain several lakes and detention areas. The drainage below
the Arsenal is primarily storm drains or roadside ditches, with capacity for only minor floods.
2.5 Clear Creek (Basin 4300)
Clear Creek is a west bank tributary to the South Platte River, and has its source in the Rocky
Mountains west of Denver. Flowing in a generally easterly direction from the Continental Divide,
Clear Creek enters the high plains in Golden. Within this lower reach, Clear Creek passes through
unincorporated areas of Adams and Jefferson Counties, and the cities of Golden, Wheatridge,
Arvada and Denver, Clear Creek crosses the northwest comer of Denver for a distance of 0.2 miles
in the vicinity of 52lld Avenue and Gray Street.
The drainage area at the mouth is 575 square miles, of which 400 square miles are in the mountain
region above Golden, There are 11 major reservoirs in the lower Clear Creek basin, three of which
are on-stream and provide some residual flood control effects downstream from each site. Ralston
Reseivoir was built in 1938 by Denver and receives water from Ralston and South Boulder Creeks.
Although Ralston Reservoir is not operated for flood control purposes, there are approximately
2,400 acre-feet of storage available. Maple Grove Reservoir is located on Lena Gulch at West 27th
Avenue and has approximately 452 acre-feet of available storage. Leyden Lake is an irrigation
water storage reservoir on Leyden Creek upstream from Indiana Street, and has approximately 550
acre-feet of uncontrolled storage.
2.6 Sand Creek (Basin 4400)
Sand Creek is an east bank plains tributary of the South Platte River. The Sand Creek basin lies in
north-central Colorado, to the east and northeast of Denver's Central Business District The Sand
Creek basin encompasses an area of 189 square miles. The basin is long and narrow, with a length
of 32 miles and an average width of 6 miles. Portions of Elbert, Douglas, Arapahoe, Denver and
Adams Counties are included in the drainage area. Sand Creek originates at the confluence of Coal
Creek and Murphy Creek. Sand Creek joins the South Platte River in the vicinity of 1-270 in
Commerce City, north of Denver city limits. The reach of Sand Creek within Denver is located
along 1-70 near the Stapleton Redevelopment area Principle tributaries of Sand Creek are Toll Gate
Creek and Westerly Creek.
2.7 Westerly Creek (Basin 4401)
The Westerly Creek tributary area consists of approximately 18 square miles of highly developed
area from the low rolling divide between Cherry Creek and West Toll Gate Creek to the confluence
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Denver Storm Drainage Master Plan
with Sand Creek. The basin is about 8.5 miles long, 3 miles wide at its widest point. The crescent
shaped area drains in a northwest-to-north direction with an average slope of 0.9 percent.
Development in the Westerly Creek drainage basin is at a state of full development consisting of
townhouses, condominiums, apartments, single family homes, motels, large shopping complexes,
streets, parking areas and highways, This development and the basin slope contribute to the rapid
response time for storm runoff and increased stormwater runoff.
The upper reaches of Westerly Creek begin in the City of Aurora, Runoff of peak events is captured
in Westerly Creek Dam, built in 1989 on the former Lowry Air Force Base at Alameda and Havana
Westerly Creek fully contains the 500-year flood event and outlets via a 48-inch pipe. Flows from
the Lowry Redevelopment area enter Westerly Creek and then are detained in Kelly Road Dam at
1 ll1' Avenue. The channel and culverts from Kelly Road Dam to Montview at the Stapleton
Redevelopment area have been improved to the 10-year storm design. The Westerly Creek channel
through the Stapleton site has been improved to 100-year capacity. All storm outfalls to Westerly
Creek within the Stapleton site have regional water quality treatment at the end of pipe.
2.8 Montclair (Basin 4500)
The Montclair Drainage basin consists of approximately 9.44 square miles (6,040 acres) and is the
largest storm drainage basin in Denver which does not have a surface drainageway. A survey in
I 861 shows two watercourses converging at present-day East Colfax and Colorado Boulevard, then
continuing northwest through present-day City Park (Ferril Lake) and onward to the South Platte
River. A 1979 Geologic Map of Denver, prepared by the USGS, shows an identical pattern of
alluvial soils as depicted in Figure 2. The Capitol Hill Storm District Number 1 created in the early
1900s financed construction of a large storm drain following this drainageway to convey storm
flows to the South Platte River. In larger storms, runoff in excess of the drain capacity follows the
original drainageway path and causes flooding at numerous locations and intersections.
2.9 Cherry Creek (Basin 4600)
The Cherry Creek tributary area consists of 410 square miles of which 385 square miles drain into
Cherry Creek Reservoir. The dam is designed to release a maximum of 300 cfs during the 100-year
event and 5,000 cfs in the Probable Maximum Reservoir Release (PMF) to the lower Cherry Creek
channel, which has a current capacity of between 4,000 and 11,000 cfs.
The lower Cherry Creek basin covers 25.2 square miles, with Goldsmith Gulch contributing 7.7
square miles of the total area. The lower channel of Cherry Creek flows 11.5 miles from the
reservoir to the South Platte River confluence in the vicinity of Speer Boulevard.
The lower channel has been improved to contain the 100-year storm from Ist Avenue to the
confluence. These improvements generally consist of cleaning, shaping, and landscaping the
channel bottom.
September 2014
2.10 Goldsmith Gulch (Basin 4601)
The Goldsmith Gulch basin encompasses an area of 7 8 square miles from Arapahoe Road
northwest to the confluence with Cherry Creek. Through Denver, the tributary area is primarily
urbanized or in the process of development from a mix of commercial and residential construction.
Many channel improvements have been completed along Goldsmith Gulch to reduce the potential of
flood damage. The channel has been stabilized and regional parks have been constructed in the
floodplain. Detention facilities have also been constructed along the channel at Bible Park, Wallace
Park, Rosamond Park and at IIiff and Monaco. Channel slopes are generally mild with several
newer drop structures along the reach.
The High Line Canal bisects Goldsmith Gulch at East Cornell Avenue Goldsmith Gulch passes
underneath the High Line Canal and East Cornell Avenue through a concrete box culvert.
The upper portion of Goldsmith Gulch includes the recent 1-25 TREX construction site. New storm
and detention facilities drain the 1-225 and 1-25 interchange to Goldsmith Gulch.
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Denver Storm Drainage Master Plan
2.11 Sloans Lake (Basin 4700)
The Sloans Lake drainage basin flows eastward from a high point near 261h Avenue and Garrison
Street in Lakewood and outfalls into the South Platte River near Colfax Avenue and Invesco Field
The drainage basin lies within Denver s jurisdiction east of Sheridan Boulevard and is bounded by
West 32nd Avenue on the north, Colfax Avenue on the south, Garrison Street on the west, and the
South Platte River on the east. The basin totals almost 5.5 square miles within Denver, Lakewood,
Edgewater, and Wheatridge. Since the basin is fully developed and heavily urbanized, the major
drainageways are not clearly identifiable. Most of the historic drainage channels have either been
filled in or built over to the point of obliteration.
The most prominent geographic feature within the basin is Sloans Lake. The lake, which occupies
176.5 acres of a 290-acre Denver park, has been and continues to be a valuable recreational resource
for the metropolitan area. In addition to its scenic and recreational significance, the lake provides
the important function of regulating and controlling downstream flows that otherwise would be
allowed to run uninhibited through West Denver. The lake reduces peak flow rates from about
2,904 cfs to 166 cfs during the 100-year event,
2.12 Lakewood Gulch (Basin 4800)
Lakewood Gulch is a major drainageway that originates in Lakewood and flows easterly toward the
South Platte River between 6th Avenue and Colfax Avenue. The Lakewood Gulch basin consists of
approximately 16 square miles beginning in the foothills and extending easterly 10 miles to the
South Platte River in the vicinity of Colfax Avenue. The tributary area is essentially fully
developed in Denver and in the eastern portion of Lakewood. The basin is also developed in the
western portion of Lakewood and Jefferson County-
2.13 Dry Gulch (Basin 4801)
The Dry Gulch basin consists of approximately 3.7 square miles lying predominantly in Lakewood,
Dry Gulch is tributary to Lakewood Gulch in the vicinity of 10th Avenue and Perry Street in
Denver, and extends westward a length of 5 7 miles along the general alignment of Colfax Avenue
to Simms Street. The basin is essentially fully developed, with commercial establishments along
Colfax Avenue and residential development comprising the remainder of the basin.
2.14 Weir Gulch (Basin 4900)
Weir Gulch meanders eastward from Green Mountain for approximately 8.3 miles to the confluence
with the South Platte River in the vicinity of West 9th Avenue. The 7.2 square mile drainage basin
is fully urbanized in Denver and mostly developed west of Sheridan Boulevard in Lakewood. Much
of Weir Gulch is lacking natural stream character and riparian vegetation Many sections of the
gulch are underground in a concrete box culvert or open on the top in a 3-sided concrete box.
There are two defined major drainageways tributary to Weir Gulch within the City and County of
Denver. The 1st Avenue Tributary to Weir Gulch is located just north of li,t Avenue and flows in an
September 20 J4
easterly direction. The drainage basin is bounded by 6th Avenue on the north, West Alameda
Avenue on the south, Raleigh Street on the east, and Wadsworth Boulevard on the west. This
tributary of the Weir Gulch system is approximately 2 miles long and about 0 8 mile wide, with an
average slope of 1.5 percent.
The Dakota Avenue Tributary to Weir Gulch lies within Denvers jurisdiction east of Sheridan
Boulevard and is located just south of Dakota Avenue flowing in an easterly direction. It is
bounded by West Alameda Avenue on the north, West Alaska Avenue on the south, Sheridan
Boulevard on the west, and Xavier Street on the east. This tributary is about 'A-miles wide and has
an average slope of 1 Vi percent.
Strip parks have been developed by the Denver Parks and Recreation Department from 1s1 Avenue
to Alameda Avenue along the gulch. This development consists mainly of grassed channels and the
installation of asphalt bike paths. Bamum Park is located on both sides of 6"' Avenue on the west
side of Federal Boulevard. Barnum Lake, located south of 6rt' Avenue has been improved to contain
the 100-year storm within the Weir Gulch channel, The open park area north of 61'1 Avenue, known
as the Federal Boulevard Detention Reservoir, is designed to reduce the 25-year flow to a 10-year
flow or less. The lower Weir Gulch channel from Federal to the South Platte River outfall has
capacity for the 10-year storm.
2.15 Sanderson Gulch (Basin 5100)
Sanderson Gulch flows 8.63 miles in an easterly direction from South Union Boulevard above
Smith Reservoir to the South Platte River in the vicinity of West Florida Avenue, This drainage
basin, which encompasses approximately 9 square miles, is fully developed in Denver and is being
rapidly urbanized west of Sheridan Boulevard. The entire basins drainage area extends west to the
top of Green Mountain, and channel slopes are generally mild.
Green belts and parks have been located along the Sanderson Gulch floodplain. Drainageway
improvements have been constructed to contain the 100-year event within open channels; however,
roadway culverts were designed for the 10-year frequency discharge.
2.16 Harvard Gulch (Basin 5200)
Harvard Gulch flows west through the southern part of Denver for a length of 5.6 miles to its
confluence with the South Platte River at Wesley Avenue. The total drainage basin area is
approximately 7.4 square miles. The High Line Canal meanders through the southeast portion of
the basin and does intercept storm flow. Single-family residences primarily urbanize the basin.
Commercial development is generally located along Colorado Boulevard, Broadway and Santa Fe
Drive. The residential portion of the basin is very dense with small lots having an estimated 52
percent average imperviousness.
The Harvard Gulch Flood Control project, completed in 1966, contains the 10-year flood
underground in a box culvert from Logan Street to the South Platte River. A grass-lined open
channel was designed though Harvard Gulch Park, with an off-line detention basin in the park.
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Denver Storm Drainage Master Plan
Highway 1-25 and the TREX construction project bisect the upper portion of Harvard Gulch
Drainage improvements for TREX through the Holly Hills area include several detention/water
quality basins as well as a new storm drain system. The TREX storm drain is connected to Denvers
existing storm drain system at two locations along the west side of 1-25: 1) the TREX storm drain
system to the south outfalls to the High Line Canal, and 2) the storm drain system to the north
outfalls to the existing 36-inch storm drain within Yale Avenue.
2.17 West Harvard Gulch {Basin 5300)
West Harvard Gulch flows east 2.8 miles through Denver to its confluence with the South Platte
River in the vicinity of Yale Avenue. The total area of the drainage basin is approximately 1.4
square miles. The average width of the basin is 0.66 mile, and the channel slopes range from 1.3 to
2,4 percent. The basin elevations range from approximately 5,525 feet to 5,250 feet,
The West Harvard Gulch Basin is primarily in residential development. Commercial areas are
situated along Federal Boulevard, and a light industrial park is located in the Basins lower reaches.
Loretto Heights College sits on the ridge that forms the southern boundary of the basin.
In the West Harvard Gulch Basin, the main drainageway was piped in an underground conduit that
extended from just above the Colorado and Southern Railroad to Zuni Street. This reach has been
restored and an improved grass lined and concrete trickle channel carries the flood events. Channel
slopes within this reach are stabilized with grouted sloping boulder drops.
During the i 00-year flood event, most of the flood flow will be contained in the channel. At the
confluence of the South Platte River, the main channel flows through an 84-inch diameter concrete
pipe. This pipe has inadequate capacity to carry the 100-year flow resulting in shallow flooding
around the Arapahoe Power Plant. Some ponding and overtopping will occur at Zuni, Clay and
Decatur Street crossings during the 100-year flood event.
2.18 Bear Creek (Basin 5500)
Bear Creek generally flows eastward from its headwaters at Mount Evans through the towns of
Evergreen and Morrison until it reaches the metropolitan area of Denver where it is tributary to the
South Platte. The basin drainage basin is approximately 36 miles long and has an average width of
about 9 miles. This encompasses approximately 261 square miles of drainage area. Elevations in
the basin range from approximately 14,260 feet at Mount Evans to 5,260 feet at the mouth. Turkey
Creek, a major tributary, drains about 52 square miles and enters into Bear Creek approximately 2
miles downstream of Morrison. A majority of the basin is in the mountains, with the remainder
draining the foothills and high plains region, The drainage basin area inside the Denvers city limits
is about 12 square miles in size.
The completion of Bear Creek Dam in 1977 just downstream of Morrison has a great effect on the
peak discharges of the 8.2-mile Bear Creek reach below the Dam. The Dam acts as a flood control
reservoir that intercepts flows from areas in the upper and middle parts of the basin. At the Bear
September 2014
Creek Dam, peak flows from the 100-year event have been reduced from 30,000 cubic feet per
second (cfs) to approximately 1,000 cfs through storage in the reservoir,
2.19 Marston Lake North (Basin 5501)
The Marston Lake drainage basin consists of approximately 2,2 square miles of limited developed
area, in the southwest comer of Denver. Various areas within the basin are subject to flooding
which could increase in severity and frequency with continued urbanization of the basin without
drainageway improvements. The basin originates approximately VS mile west of Kipling Street
between Belleview and Quincy Avenues, and extends approximately 4.4 miles in a northeasterly
direction to its confluence with Bear Creek. Continued development in these areas, planned for
mostly residential with some light commercial business, is expected to increase runoff rates.
Marston Lake is owned and operated by the Denver Water Board and serves as a major link in the
water supply system for Denver and much of the metropolitan area. The Lake acts as a sump and is
isolated from receiving or discharging stormwater.
The drainage basin traverses various jurisdictions and ownerships including Jefferson County,
Denver, Denver Water Board, Marston Water Treatment Plant grounds, Pinehurst Country Club
Golf Course, and United Sates Government properties to the south of Fort Logan National
Cemetery.
Improvements to the drainageway have been accomplished by the Denver Water and by the
UDFCD. The north side of the Marston Lake Dam was reconstructed to allow room for an open
channel, which, along with an improvement completed by the UDFCD provides improved 100-year
capacity channel from Old Wadsworth Boulevard to West Quincy Avenue.
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Denver Storm Drainage Master Plan
3.0 CAPITAL IMPROVEMENTS PROGRAM
3.1 Cost Modeling
Development of cost estimates is an important component of the master planning process. Costs
have been compiled to assist in the evaluation of drainage alternatives and to provide for systematic
capital budgeting for future improvement programs. Bid data has been obtained from the City and
County of Denver for the period 1999 to 2013 and statistically analyzed to derive regression
equations that reflect typical construction practices within the City and County of Denver, A
detailed tabulation of all unit costs and a listing by project is shown in the GIS Appendix and
linked to the GIS database for project cost analysis, General unit costs (in 2013 dollars) are
summarized below:
Storm Drain (18 in. and < 72 in,):
Storm Drain (> 72 in-120 in.):
Elliptical Storm Drain
Jack and Bore Pipe (< 48 in ):
Jack and Bore Pipe (> 48 in.):
Box Culverts:
Headwalls:
Manholes:
Manhole Cone floe Box Culverts
Inlets:
Inlet laterals:
Stormwater Detention:
Asphalt Patch (assumed 8-ft
wider than the pipe diameter)*
Wet Utility Relocation Cost:
$ 4.27 to $5.67 per inch diameter per lineal foot
$ 5.95 to $8.89 per inch diameter per lineal foot
! */2 times the equivalent round pipe
$ 27.36 per inch diameter per iineal foot
$ 100,00 per inch diameter per lineal foot
$ 600 per cy concrete, plus $0.85 per lb. steel
$ 600 per cy concrete
$ 3,181 $14,700 each Type A, C, B and P
$1,800 each
$ 4,200 for typical 6-foot Type 14 curb opening
Assumed four inlets constructed per manhole
Assumed 20 feet of 18-inch RCP per inlet
$ 75,000 per acre-foot
$ 8.00 per sy-in ($145.46/ton) for
assumed 9-inch full depth section
$2,740 per crossing for sanitary sewer avoidance
$1,370 to $27,360 for relocation of water, depending
upon size
Indirect costs and contingency have been expressed as a percentage of direct construction costs.
These include the following:
Traffic Control: 3%
Mobilization / Demobilization: 10%
Design & Engineering: 15%
Materials Management (Limited Envi. Remediation and Disposal)* 7%
Contract Administration / Construction Management: 10%
Contingency: 25%
Environmental Compliance (Erosion Control, etc.)________________________3%
INDIRECT COST TOTAL
73%
Note: Property acquisition is specific to final design and not included in the project costs.
September 2014
3,2 Summary of Capital Costs
Cost by Project
A summary of costs for ail basins and all projects within those basins is presented on the following
pages, sorted first by basin, and then sorted by project. Costs are tabulated through automated GIS
electronic master planning routines and are based upon unit prices developed in 2013. In some
cases, the automated costing may not match exactly hand calculated project costs shown in the
individual Technical Appendix notebooks. However, great care has been taken to ensure these
differences are within 5% or less.
This Drainage Master Plan does not distinguish between Developer cost and City cost. In particular,
capital improvements have been shown for new developing areas (i.e., Stapleton), although their
funding will certainly be borne by different entities and budgets than for retro-fit improvements of
existing development.
Cost by Basin
For purposes of developing an overall construction cost by basin, costs are summarized on the
following pages to show the total cost of the Recommended Plan. This consists of all the projects
shown, excluding those with an asterisk (*).
Projects shown with an asterisk have been excluded from the Recommended Plan in favor of an
alternative evaluated in the same drainage basin in order to provide a level of service necessary to
drain or protect sump locations (0060-01, 0061-02); meet street depth criteria (4400-02, 4600-02);
removing floodplain (4700-01) and other drainage considerations (0061-02, 5100-01).
The total project cost to upgrade the Citys storm drainage infrastructure, to meet minimum current
drainage criteria in the Recommended Pian for the entire City, is estimated to be $1,478,025,513 in
2013 dollars.
Page 19


Denver Storm Drainage Master P!an
September 2014
RECOMMENDED PLAN
SUMMARY OF PROJECT COSTS
BY COLLECTION SYSTEM
ID OUTFALL NAME/LOCATION RECOMMENDED PLAN NOTES CIPCOST (2013 Dollars)
0058-01 South Platte River Prairie Gateway SO
0059-01 South Piatte River Globeville Utah Junction S62,253.21 4
0060-01 South Platte River 1-70& Colorado Boulevard Excludes Projects F and FI & uses 100-year Alternative 514,280.053
0060-01-100YR South Platte River 1-70& Colorado Boulevard 56,834,404
0060-02 South Platte River 1-70 & York 550,044,259
0061-01 South Platte River 27th & Federal 569,285,056
0061-02 South Platte River Highland Excludes Projects B, H andj & uses 100-year Alternative 570,145,923
0061-02-1OOYR South Platte Rivet Highland 525,199,832
0062-01 South Piatte River Lower Platte Valley 534,581,126
0063-01 South Platte River Central Platte Valley 568,436.129
0064-01 South Platte River 1 st & Federal 510,284,557
0064-02 South Platte River Valve rde 529,296,233
0065-01 South Platte River Ruby Hill 516,013,182
0065-02 South Platte Rivet Dartmouth 5492,604
0067-01 Soutit Platte Rivet College View 33,441,705
0067-02 South Platte River West Belleview S2,311,003
0067-03 No Outfall Marston Lake SO
3501-01 Second Creek West Fork Second Creek 51 7,838,865
3700-01 First Creek First Creeks Pena Corridor SO
3 700-02 First Creek First Creek-Green Valley Ranch SO
3700-03 First Creek First Creek Dogwood & Blue Gamma Trlbs. 518,999.763
3702-01 First Creek First Creek-Tributary T" SO
3900-01 Irondale Gulch Irondale Gulch Stapleton SI,271,550
3900-02 Irondale Gulch Irondale Gulch East Mantbello 52,509,053
3900-03 Irondale Gulch Irondale Gulch Parkfield SO
3900-04 Irondale Gulch Irondale Gulch Majestic Commerce Center 518,094,707
3901-01 Irondale Gulch Irondale Gulch West Montbello 543,779,847
3901-02 Irondale Gulch Irondale Gulch Gateway SO
4000-01 Rocky Mountain Arsenal Stapleton West Section 10 S6.61 7,250
4300-03 Clear Creek Clear Creek North of 1-70 57,681,489
4309-01 Clear Creek Berkeley Lake SO
4400-01 Sand Creek North Stapleton SO
4400-02-1 OOYR Sand Creek Quebec Corridor Recommended Street Depth Criteria Alternative 576,510,599
4400-03 Sand Creek Stapleton 58,926,694
4400-04 Sand Creek East Stapleton S26,8S8,165
4401-01 Westerly Creek Westerly Creek South Stapleton SI,962.249
4401-02 Westerly Creek Westerly Creek i 1th Avenue to Montview 54,681,400
ID OUTFALL NAME/LOCATION RECOMMENDED PLAN NOTES CIP COST (2013 Dollars)
4401-03 Westerly Creek Westerly Creek Lowry SO
4401-04 Westerly Creek Westerly Creek South of Alameda 314,046,203
4500-01 Montclair City Park 367.090,422
4500-02 South Platte 36th & Downing 350,339,294
4500-03 Montclair Park Hill Colfax 343.363,416
4500-04 Montclair Park Hill 6"1 Avenue 381,571,195
4600-01 Cherry Creek Central Business District 363,347,951
4600-02 Cherry Creek Cherry Creek Mall 368.015,612
4600-02-100YR Cherry Creek Cherry Creek Mall Recommended Street Depth Criteria Alternative 315,488,679
4600-03 Cherry Creek Upper Cherry Creek 337.029,014
4600-03-1 OOYR Cherry Creek Upper Cherry Creek 311.790,690
4600-04 Cherry Creek Cherry Creek Reservoir 34.961,467
4601-01 Goldsmith Gulch Lower Goldsmith Gulch 312,141,664
4601-02 Goldsmith Gulch Middle Goldsmith Gulch SO
4700-01 Sloan's Lake Sloan's Lake Excludes Projects Cl and D& uses 100-year Alternative 33,640,712
4700-01-1 OOYR Sloan's Lake Sloan's Lake 314,830,043
4800-01 Lakewood Gulch 12th & Federal 38,595,513
4801-01 Dry Gulch 12th & Sheridan SO
4900-01 Weir Gulch Weir Gulch 34,948,695
5000-01 1-25 & South Platte West Washington Park 318,439,886
5000-02 1-2 S University & Mexico North 317,570,255
5000-03 1-25 University & Mexico South 310,387,265
5100-01 Sanderson Gulch Sanderson Gulch Excludes Project 0 & uses 100- year Alternative 554,928,579
5100-01-100YR Sanderson Gulch Sanderson Gulch Uses Project O only 36,630,258
5200-01 Harvard Gulch Harvard Gulch Lower Basin 335,644,580
5200-02 Harvard Gulch Harvard Gulch Middle Basin S 39,004,01 6
5200-03 Harvard Gulch Harvard Gulch Upper Basin 359,028,108
5300-01 West Harvard Gulch West Harvard Gulch 38,1 55,827
5401-01 Greenwood Gulch Greenwood Gulch SO
5500-01 Bear Creek Bear Creek Fort Logan 5 7,407,582
5SOO-02 Bear Creek Upper Bear Creek 513.346,391
5500-03 Bear Creek Academy Park 50
5500-04 Bear Creek Beat Creek Marston Lake North 34,172,61 5
5500-OS Bear Creek Pinehurst Tributary 33,478,670
5501-01 Bear Creek Henrys Lake SO
5901 -01 Dutch Creek Coon Creek SO
RECOMMENDED PLAN TOTAL 51,478,025,513
Page 20


Denver Storm Drainage Master Plan
September 2014
ST A TEMEHT OF PROBABLE COSTS IN 2013 DOLLARS
PROJECT HARD COSTS INDIRECT COSTS TOTALS
COLLECTOR SYSTEM ID PROJECT PIPE MANHOLE INLETS ASPHALT PATCH WET UTILITY RELOCATE DETENTION TOTAL CONSTRUCTION COSTS TRAFFIC CONTROL (3%) MOB ILEA TION/ DEMOBILIZATION (10%) DESIGN & ENGINEERS G (15%) MATERIALS MANAGEMENT (7%) CONTRACT ADMINISTRATION / CONSTRUCTION MANAGEMENT (10%) CONTINGENCY (25%) ENVIRONMENTAL COMPLIANCE (3%) TOTAL TOTAL BY COLLECTION SYSTEM
0059-01 A 40TH AVF OUTFALL (A} S13.613.353 $468,928 S1.1S5.0OO $1,303,220 $310,720 $17,091,821 $512,755 $1,709,132 52,563,773 S1.19S.427 $1,709,102 S4,27Z955 $512,753 $29,568,850 932 253 214
B 40TH AVE OUTFALL fB) S6S5.224 $7,811 $73,200 $176,332 59,590 $952,657 $28,580 ^5 266 $142,899 $66,636 $95,266 $230,164 $28,500 St 648.098
c 4STH AVE OUTFALL (C) $5,220,660 319,600 $268,400 $42,470 £5,551,330 £166,540 $555,133 $832,700 £388,593 £555,133 $1.387,832 3155,540 S5.603.001
E 51 ST AVENUE COLLECTION SYSTEM 55,931,743 $432,514 S75S 400 S1 057,232 $109,540 $8,287,429 $240,623 $823,743 $1,243,114 $500 120 $828 743 $2,071 857 3240,623 $14,337,252
J INTERSTATE 70 OUTFALL S2.521.9T1 572,026 S536 800 $690,752 $39,730 S3,861,279 S115,830 S386.120 $579,192 $270,290 $386126 S9G5.320 3115,030 $6,680,013
L 4STH AVE AND GRANT ST POND 5240,000 $240,000 £7,200 $24,000 $36,000 $16,800 $24,000 560.000 57.200 £415,200
0060-01 F ' PARK HILL PHASE VI* $1,313,468 S180666 $317 200 S632 604 $58,870 $2,502,828 £75,085 £250,283 $375,424 S175 19$ S250 283 S625.707 $75,085 $4,329,833 £20,016,218
F1 * PARK HILL PHASE VII * $395,922 $63.766 $97,600 $199,272 $57,470 S814.0GG $24,421 S81.403 $122,104 $56 932 $31,403 2203,500 $24,421 St408,272 *
G 50TH AVE INTERCEPTOR $1,090,449 $137,996 $195,200 $315,540 $17,810 $1,756,997 £52.710 £175,700 $263,550 $122,900 5175700 £439,249 $52,710 $3,033,606
H COLUMBINE AND YORK UPGRADES $748,110 $135,068 $368,000 $614,740 $87,600 $1,952,518 $58,576 $195,252 £292.878 £136,676 £195.252 £488,130 $58,575 £3,377,858
I RIVERSIDE OUTFALL 52,609.959 $30,265 3317.200 33.740 $2,960,164 $88,305 $296,016 S444.Q25 $'207.211 $296,016 $740,041 $88,005 £5.121 0B3
L N COLORADO BLVD IMPROVEMENTS $419,219 S67.587 $512,400 $285820 £9.580 $1,294,606 £38,838 $129,461 5194,191 $90,622 5129.461 £323.652 $33,838 £2,233,663
M MILWAUKEE ST IMPROVEMENTS $97,750 310,329 $73.200 $108, S00 S290.079 58.702 $29,003 $43,512 S2Q.306 S29.0D8 £72.520 53.702 $501,837
0060-01-100YR F PARK HILL PHASE VI 51.640,688 5130,666 3317.200 $657,144 $60,240 32,855,930 $85,673 3265.594 $423,391 $199,916 S285.5&4 $713,934 $85,678 $4,940,773 $6.634 404
F1 PARK HILL PHASE VII S655.5DG 363756 $97 600 $220,246 $57,470 $1,094,584 £32,330 $109,450 $104,103 £76,621 S109 458 $273.646 $32,038 $1 893.631
0060-02 A E 45TH AVE SYSTEM $4,109,680 S611.777 $1,317,600 $2301.564 £220.450 £8,555,071 £256,652 $855,507 $1,283,261 £598.855 £655.507 $2,138,768 £256,652 S14. SOD. 273 S50.044.2SI
B N BRIGHTON BLVD OUTFALL 55,068,859 £423 602 $732,000 $1 223 524 £93,120 30,341,395 5250,242 5834 140 51,251.209 £583,898 EB34.140 S2.O05.34& £250,242 514.430,615
c N RACE ST OUTFALL $3,917,511 $439 062 $1 049 200 £1 524.592 £133,030 $7,123,395 £213,702 S712.340 $1,068,509 $498,63$ $712,340 S1 7 60.843 £213,702 $12,323,475
D NATIONAL WESTERN IMPROVEMENTS $3,182,133 £236.431 $732,000 £664.340 372,550 £4,907,454 $147,224 £490,745 £736,118 £343,522 £490,745 31.226,864 £147,224 £8.489,896
Q0S1-01 A 1STH AND 23RD AVENUE OUTFALLS $1,329,434 565,652 $219,600 £350.696 £24,560 31.990,242 £59,707 5199,024 5290,533 S139,017 £199,024 £497.560 355,707 £3,443,117 369,285.056
B 20TH AVENUE COLLECTION SYSTEM $1,051,395 $182,993 $780 600 £1 077 652 £152,010 S3.244,850 $37,346 $324,485 $466,723 $227 140 $324,465 $611,212 $07,346 £5,613.592
c 20TH AVENUE OUTFALL 53,712,239 $261,537 3610,000 S1,130.420 S116,410 S5.830.606 $174,913 $503,061 3074,591 $408,142 $503,061 51,457,652 $174,910 $10,006,949
24TH AVENUE COLLECTION SYSTEM 52,392,764 $309,496 $1,244 400 £2.011.488 $300,000 36.266.140 5107,904 5626,615 S93&.G22 $438,630 £626,615 51,566.537 3107,964 £10,840,435
E 2STH AVENUE COLLECTION SYSTEM $3,191,622 5484.309 31,122.400 $2 094 612 £294,310 £7 187,253 £215,618 £718,725 51,078,088 $503.108 £718,725 S1.796.S13 £215,618 $12,433,948
F 7TH STREET OUTFALL 54.374.029 $219,553 3658.800 St 168.672 $188,920 $6,609,974 $103,299 $660,097 S9S1.496 $462,693 $660,397 51,652,494 $190,205 $11,435,254
G central street collection and OUTFALL SYSTEM 51,555,050 $239,252 £029.600 St050296 $266,090 S3.959,096 $110,797 5395,990 5593,904 $277,193 S395.S90 £989.974 3110,797 £6,850,621
H UPPER 29TH AVENUE AND UPPER ZUNI COLLECTION SYSTEM $1,772,437 S2T1.191 31,024 800 S1.661.768 £230,000 £4.960,196 £148,806 S4S6.020 £744,029 $347,214 £495,020 £1,240049 £148,806 S8.5B1.140
0051-02 A W 34TH/35TH AVENUE COLLECTION SYSTEM 51,849.381 $216.147 SS27.2Q0 St597.152 $282,000 S4.871.880 $146,156 $407,100 $730,782 $341,032 $407,108 51,217.970 $146,156 S3.423,352 $95,009,390
6 * W 34TH AVE AND LIP AN ST OUTFALL * 54,432,880 $87,522 3292.800 $511,732 $15,070 $5,340,004 $160,200 $534,000 $001,001 $373,600 S534.000 S1 335,001 3160,20C $9,238,206 *
G 40TH AVENUE AND FEDERAL COLLECTION SYSTEM $3,363,017 $475,309 $1,317 600 $2 375,028 £273,860 £7,804.814 $234,144 £780,481 51,170,722 £546,337 £780.461 $1 951 204 £234,144 $13,502,327
D 42ND AVENUE AND FEDERAL COLLECTION SYSTEM $1,255,075 $110,438 £760,600 $1,211,028 $99,970 $3,458,111 £103,743 S345.811 5513,717 £242,063 £345,811 £864.528 £103,743 £5,982,532
E W 46TH AVENUE COLLECTION SYSTEM $1,116,206 $172,696 3536.800 SB93.134 S67.110 £2.705.996 $83,560 $278,600 $417,099 S105,020 $278,600 S696.4S9 S83.58C $4,819,774
F W 47TH AVENUE COLLECTION SYSTEM $2,303,855 $370773 $902,800 $1,280,020 £116,390 £4.973.848 £149,215 $497,385 $746,077 £348,169 £497.365 $1,243,462 S140.215 SB.604.756
G CHAFFEE PARK INTERCEPTOR $1,793,065 $596,512 £1,073,600 $1,395 496 £153.360 $5,012,033 £150,361 $501,203 £751,805 £350,842 £501,203 $1,253,008 £150,361 £8.670,016
H ' FOX STREET OUTFALL * $3,706,424 $143,003 S268.400 $547 696 £13,700 £4.759.223 £142,777 $475,922 £713,383 £333,146 $475,922 S1 139.806 £142,777 £Bl233,456 *
1 LOWER W 38TH AVENUE COLLECTION SYSTEM 53.344.033 $278,844 S758.400 $1,519,308 $165,650 $6,064,235 $181,927 3006,424 $909,635 $424,496 $606,424 $1,516,059 $1B1,&27 $10,401 127
J* LOWER INCA STREET COLLECTION SYSTEM UPGRADES - $2,362,074 3281,089 3683.200 $1,273,808 £134,180 $4,735,151 S142,055 $473,515 £710,273 5331,461 $473,515 $1.163788 £142,05? £8,191,613'
K UPPER W 38TH AVENUE COLLECTION SYSTEM $2156,533 $490,036 $1,098,000 £1,631,572 £191,720 $5,575,861 £167,276 $557,586 £836,379 £390,310 $557,536 $1,393 965 £167,276 £9.646.239
ooeuoa-tooyR L NORTHWEST SUBAREA INTERCEPTOR STORM SEWER 511,921,236 $377,461 3683.200 $1,499,560 $84,920 $14,566,377 $436,991 $1 456,630 $2,184,957 $1,019,646 $1,456,638 $3,641,594 $436,991 S25.19S.S32 $25,199,332
0062-01 F 27TH ST INTERCEPTOR PHASE 1 $3,976,740 S130,598 $195,200 S349.SBS $21,920 S4.674.354 £140,231 $467,435 £701,153 £327,205 £467,435 SI 168.588 £140,231 $0,006,632 S34.581.126
G 27TH ST INTERCEPTOR PHASE 7 $3,298,360 $202.298 3292,800 S6B0.248 £106,810 £4.580,516 £137,415 £456,052 £887,077 £320,636 £458,052 £1,145.129 3137,415 £7.924,292
H 27TH ST INTERCEPTOR PHASE 3 51.077,213 $-237,757 S463.600 $733,432 361,630 $2,573,672 $77,210 $257,367 $386,051 $180,167 $257,367 $643,418 $77,210 S4 452.452
1 27TFI ST INTERCEPTOR WALNUT/MARKET LATERAL $566,694 $97,465 $122,000 $350,072 £10,960 $1,149,191 534,476 $114 919 £172,379 $80,443 £114,919 $207 298 $34,476 $1,980,101
J 27TH ST INTERCEPTOR CHAMPA LATERAL $1,334,621 $112,747 3365.000 $727,880 £46,560 £2,586,008 $77,640 $258,801 £388,201 £181,161 £258,801 £647.002 £77.646 £4,477,254
M GRANT ST STORM CRAIN 52.370,375 $306,259 S610.000 $888,978 S247.740 $4,423,350 S132.700 $442,335 $663,502 $300,635 $442,335 $1,105,038 $132,700 S7,652,395
0063-01 A W I3TH AVE OUTFALL $1,514,623 $299,223 $683,200 $952,245 $136,860 £3,506.154 £107,585 $358,615 5537,923 £251.031 £350,615 $096,538 $107,585 $6 204.046 sea 436 129
0 W 7TH AVE OUTFALL ST. 397.296 $374,685 $683,200 5955,884 £36,980 29 448,045 £283,441 £944,804 51,417,207 $661,353 $944.00.4 S2.362.011 £283,441 £16,345.116
C W BAYAUD AVE OUTFALL 57,106,703 $592,293 £2.2^.200 S3,179,736 S395.62Q 513,523.552 $400,707 £1.362.355 52,043,533 5953,649 £1,362.355 $3405.888 5400.707 £23,568,746
D W ELLSWORTH AVE OUTFALL $1,193,450 $43,769 $73,200 $78,440 $13,320 $1 401 179 $42,035 $140,118 £210,177 £90,003 $140,110 $350,295 $42,035 $2 424.040
E W MULBERRY PL OUTFALL 32,535.319 $78,176 S536;0OG $683,124 $94,430 $3,927,849 $117,335 $392,785 3589,177 $274,949 $392,785 $901,962 $117,835 $6,795,177
F W 3RD AVE OUTFALL 53.059,150 $253,045 $585,600 S672.546 369,040 £5,450,183 $163,505 5545,010 5017.527 5301,513 S545.O10 SI, 352,545 5163.50? £9,428,815
G W COLFAX AVE IMPROVEMENTS $707,881 $146,075 S610.000 $607,620 $47,920 £2 121 4S6 S63.S45 $212,150 $318,224 $148,505 $212,150 $530,374 $63,645 $3 670.1S9
0064-01 A W 3RD AVE OUTFALL 535.595 S9.543 373,200 Si 11,724 50,220 $260,282 $0,640 $23,828 $43,242 $20,180 $28,028 572,070 30,648 $498,726 S1O204.557
B WSTH AVE OUTFALL $099,996 $21,905 SI 70,000 3293,460 310,960 £1,197.121 535,914 5119,712 5179,565 $83,798 5119,712 £299,280 £35.914 52,071.016
G W 5TH AVE OUTFALL $2639.959 $141,194 3610.000 $938,216 £130,060 £4.459,429 £133,783 £445.943 S66B.914 £312,160 £445.943 31,114,857 £133,783 £7714,812
DC54-02 A 16" UPGRADES $140,960 S29.415 $219,600 $194,432 52,740 $595,147 $17,354 S5&.515 $89,272 $41,660 $59,515 $148,707 $17,854 $1,029,604 $29,296,233
B S HURON ST OUTFALL 3168,103 $16,684 $97,600 $166,144 $26,010 $474,541 $14,236 $47,454 $71,181 £33,218 £47,454 $118,635 $14 286 $820,955
G W ALAMEDA AVE OUTFALL $8,197,851 $338,220 $1,073,600 £2.192.220 £308,010 £12.109.901 £363,297 £1,210.990 51,816,485 £847,699 £1,210,990 33,027,475 3363,297 £20,950,128
D W ARIZONA AVE OUTFALL S1,506.925 $46,969 $148,400 $270,100 S34.230 $2,004,624 $80,139 $200,462 $300,394 $140,324 $200,462 $501,156 $60,130 $3,468,000
E W TENNESSEE AVE OUTFALL S949 938 $104,338 $219,600 £450.120 526,030 $1 750 026 $52,501 $175 003 £262,504 £122,502 £175,003 $437,506 $52 501 £3 027.546
0055-01 A 18" UPGRADES $32,490 329,447 $48,300 £42,408 £153.145 S4.594 315.314 £22,972 £10.720 $15,314 £38,286 £4.594 £264,939 S16.013.182
B SLIPANST OUTFALL $2,374,808 313,454 £122,000 £344,032 538,320 S2.892,694 $86,781 S289.269 £433,904 £202,489 $289,259 £723,174 SB6.781 £5,004.361
c S PECOS ST AND W ILIFF IMPROVEMENTS 51 192,639 $176,367 $390,400 £443,876 $21,900 £2,230.182 $66,905 S223.018 £334,527 S156.113 £223,018 $557,546 $66,905 £3,853,214
D1 W EVANS AVE IMPROVEMENTS $876,100 $133,158 5195,200 $390 780 323,290 $1,620,520 $48,016 $162,053 $243,079 S113,437 S162,053 $405,132 340,616 $2 003,514
D2 W EVANS AVE EXTENSION S1.146,559 $218,203 $317,200 $611,944 $65,720 32,359,626 $70,789 $235.963 £353,944 5165,174 £235,963 £589,906 $70.78$ $4,002,154
Page 21


Denver Storm Drainage Master Plan
Stpltunbcr 2014
STATEMENT OF PROBABLE COSTS IN 2013 DOLLARS
PROJECT HARD COSTS INDIRECT COSTS TOTALS
COLLECTION SYSTEM ID PROJECT PIPE MANHOLE INLETS ASPHALT PATCH Wet UTILITY RELOCATE DETENTION TOTAL CONSTRUCTION COSTS TRAFFIC OONTROL (3%) MOBILISATION 1 DEMOBILIZATION (10%) DESIGN £ ENGINEERS G (15%) MATERIALS MANAGEMENT (7%) contfsact ADMINISTRATION / CONSTRUCTION MANAGEMENT (10%) CONTINGENCY (25%) ENVIRONMENTAL COMPLIANCE (3%) TOTAL TOTAL BY COLLECTION SYSTEM
0065-02 A S BRYANT ST IMPROVEMENTS 294,300 S9.543 $73,700 S104.960 $2,740 5234,743 $8,542 $28,474 £42.7*1 S19,932 528,474 $71,186 $8,542 £492,604 $492,004
ooerr-oi A S QUITMAN ST IMPROVEMENTS 5250.530 531,810 $244,000 S334.040 £31,510 £931.860 £27,956 393,106 $139,779 £65,230 $93,185 $232,965 £27,956 $1 612.110 $3,441,705
B W UNION AVE IMPROVEMENTS $345.185 330.006 5292. BOO 5308,064 531.510 £1.057 565 £31,727 $105,756 £158,635 S74.030 £105,756 £264,391 $31,727 $1.829587
0067-02 A W GRAND AVE IMPROVEMENTS $514,559 $102,943 $258400 5406,108 $43,830 $1,335,840 S40.075 £133,584 £200,376 $03,509 $133,584 £333,960 £40.075 52,311,003 £2,311,003
3501-01 A HIGEPOINT OPEN CHANNEL S4,2.16,000 521,334 $36,664 £30,100 £4,306,340 £129,190 £430,635 $545,952 £301,444 £430,635 $1,076,587 $129,190 S7 449,981 $17,-$38,865
c SECOND CREEK GRADE CONTROL $5.704.591 $147,136 5153,408 £6,005.135 S1S0.154 3600.514 £900.770 S420.35S $600,514 S1.501.2S4 $180,154 SI0,308,884
370003 A IRONDALE GULCH DETENTION 01 $975 000 S975.000 S29.250 £97,500 $146,250 550,250 $97,500 £243,750 £29.250 $1,585,750 31 & 999.763
E POND 802 DETENTION 32.744.592 S11.074 $24,400 £27.456 $2,475,000 $5,202,522 $158,476 $528,252 $792,378 $369,777 $528,252 $1,320,630 3158.476 £9,138,703
G IRONDALE GULCH DETENTION 06 S3.000.000 £3.000.000 $90,000 £300,000 £450.000 £210,000 £300,000 £750,000 $90,000 55.190,000
H IRONDALE GULCH DETENTION 07 81 725 000 $1 725 000 £51 750 £172.500 $250 750 S120.75D £172,500 £431,250 £51 750 $2,984,250
3900-01 A STAPLETON 10 $735,000 S735.000 322,050 $73,500 $110,250 551,450 $73,500 3183,750 $22,050 51,271,550 $1,271,550
3900-02 A E 53RDAVE IMPROVEMENTS $259,960 $27,222 5146.400 5256,080 S20.550 S710.212 521,306 £71,021 $106.53? £49,715 £71,021 £177,553 $21,306 S1.22S.56S £2.509.053
B E MAXWELL PL IMPROVEMENTS $283,054 $27,312 5170 BOO 5238392 £20,550 3740 108 S22.203 £74 011 £111,016 £51,008 £74,011 5135,027 322.203 $1,200,367
3900-04 B E BOLLING DR IMPROVEMENTS S5.434.368 55,025,000 510,459,368 S313.781 $1,045,937 $1,563,905 $732,156 51,045,937 $2,614,842 $313,781 Si 8,094,707 S1 a, 0,94.707
3901-01 A 16" UPGRADES 5201.595 528,629 $219,600 5231,012 $0,220 3639,046 £20,671 568,905 £103,357 £48,233 $65,905 2172,262 £20.571 $1,192,050 $43,779,847
B E 45TH AVE IMPROVEMENTS $6,533,270 $402,532 £780 800 51,732.480 £197,140 £11.695 232 £350,887 £1.169623 $1,754,435 £818,736 £1,169,623 £2,924,058 $350,807 $20,234,401
C E 47TH AVE IMPROVEMENTS S3.407,680 5217/943 $354,000 51,517.336 $281,930 $6,270,809 $188,367 $627,889 $341,833 $439,522 $627,880 $1,563,722 $188,367 310,862,478
E 53RP AVE IMPROVEMENTS 52,794,394 $224,752 5365,000 £700,994 S50.550 £4.136,700 $124,103 3413,670 £520.517 $289,575 S413.678 51,034.195 $124.10? 57.156.629
E E ALBROOK DR IMPROVEMENTS $765,939 $218,231 $341,600 5465,656 550,670 £1.862,096 355,863 $186,210 £279314 £120,347 £186,210 $465,524 355,883 $3,221,427
F E ANDREWS DR IMPROVEMENTS $230.851 S23.S43 S170.000 $203,512 50,220 SS43.226 S19.297 $64,323 £96,484 $45,026 $64,323 $160,806 S19.297 $1,112,732
403001 A POND ZD £3.825.000 $3,825,000 5114.750 £382.500 S573.750 $267,750 $352,500 $956,250 $114,750 $6,617,250 56.617,250
430003 A N FEDERAL BLVD OUTFALL 31,150,444 $179,823 5463,600 5638,280 841.060 £2.723 207 $81,696 $272,321 £408,481 £190,624 £272,32* £680,002 381.896 $4711,148 £7.661.483
B CLEAR CREEK OUTFALL S1.145,000 S62.500 $122,000 $334,720 $2,740 S1.716,060 551,505 S171.6S6 $257,544 $120,187 $171,696 $429,240 £51.509 S3.970.341
440002* A ' 39TH AVENUE/ELM STREET IMPROVEMENTS * 51,327,564 $213,665 S366.0Q0 5630,320 $80,770 £2.626,319 £76,790 £262.632 £383,940 £103,042 $262,632 $656,580 S78.790 S4 543 533 $45633,319
B1 * 33TH AVENUE S HOLLY STREET COLLECTOR * 53.257,603 $350,859 £610.000 31,114,084 £110,900 £5,454 276 £163.528 $545 428 £818 141 £381,799 £545,428 $1,363,569 $163,628 .59.435.897 *
B2 * 3BTH AVENUE & HOLLY1 STREET COLLECTOR EXTENSION * S3.470,174 $390,736 $1,171,200 .171,764 $312,110 37.526,034 $225,781 £752,603 $1,128,905 $526,822 $752,603 51,88-1,500 $225,781 $13,020,037 *
O' IVANHOE/WY STREET COLLECTOR LATERALS* S416.657 $112,143 £292,000 5395,760 £42,470 51.261.838 £37,055 £126,104 $189,276 S00.32S $126,184 $315,460 537,055 £2,162,931 *
D" 3STH AVENUE INTERCEPTOR * S1.480,164 $136,238 £244.000 5514,704 £121,810 £2,496,916 $74,907 $249,692 £374.537 £174,784 £249,692 £624,229 £74,907 £4,319664*
E * 33TH AVENUE INTERCEPTOR * 51.050,008 $166,298 £244,000 5455,772 515,070 $1.919.16B 557.575 £191,917 $207,375 £134,342 £191,917 £479,792 £57,575 £3 320.161 *
F2 * UPPER PARK HILL OUTFALL * 52,109,556 $317,336 $875,400 31,616,004 S169J90 £5,093 090 £152,793 £509,309 $763,964 £356,516 $503,309 S1,273,272 £152,793 $8,811 046'
J 40CMP-100 VR (street depth critena) A 39TH AVEMUE/ELM STREET IMPROVEMENTS 32.253,963 $357,664 £610,000 $1,171,636 £124,600 £4,518 063 £135,542 $451,806 £677 709 £316,264 £451,806 $1,129,516 $135,542 $7,015,248 £76,510,593
B1 35TH AVENUE & HOLLY STREET COLLECTOR 55,325,517 $377,244 $610,000 $1,256,008 $143770 SB.212.539 $240,376 £821,254 £1 231.881 £574,076 £821.254 £2,053,135 £246,376 £14,207,693
B2 3BTH AVENUE 8 HOLLY STREET COLLECTOR EXTENSION S5,517,000 £572,765 $1,171,200 £2,319,072 £338,100 59,910.137 £297,544 $951,014 $1,487 721 $694,270 £991,014 S3,479,534 5297.544 £17,158,370
c IVANHOBIVY STREET COLLECTOR 55.169.214 $445,096 5707,600 31,611,296 393,530 £8,031 836 S240.B55 $803,184 $1,204,775 £562,229 £803,104 $2,007,959 $240,955 313,895,077
D 33TH AVENUE INTERCEPTOR S3.457.792 $129169 $317,200 5595948 $294,190 $4,794,299 $143,929 £479,430 $719,145 $335,601 £479,430 £1,190,575 $143,829 S8.294.138
E 39TH AVENUE INTERCEPTOR 51,119,909 £166,298 $244,000 S4G4.624 £15,070 £2.009,901 S60.297 $200,990 $301,405 $140,693 $200,990 $50.2,475 £60 297 $3,477,128
F'2 UPPER PARK HILL OUTFALL 53.506.906 $428,267 5878,400 51,756 272 £171,160 £6.741 005 £202,230 $874,100 $1,011,151 £471,070 £874,100 $1,605,251 $202,230 311,661,537
4400-03 A STAPLETON-04 $190,000 $37,500 S73.200 5140,000 S440.700 $13,221 $44,070 £66,105 £30,849 £44,070 £110,175 $13,221 S762.411 $8,926,694
c Quebec st outfall $3,066,234 £309,520 $512,400 $746,244 £84,350 £4.719,236 £141,577 £471,924 $707 686 $330,347 $471,924 £1,179,010 $141,577 $8,164,283
4400-04 A STAPLETON OS S3,701.832 S20.798 3146,400 $506,544 £20,530 S4.476.104 $134,283 $447,610 $671,416 $313,327 $447,610 $1,119,026 $134,283 $7,743,659 $26,858,165
C STAPLETON 06 37.195,165 $431,679 $1,171,200 $2,110,984 $139,620 £11,046,048 $331,465 $1,104,885 $1,657,327 £773,419 £1,104,885 £2,762,212 '3331.465 £19,114,506
4401-01 A STAPLETON-09 5234,076 £95,425 S536.600 £262,460 S5.480 £1 134,249 £34,027 $113,425 $170 137 $79,397 £113.425 $203,562 $34,027 Si .902,249 SI 902.249
4401-02 A E COLFAX AVE OUTFALL $182,726 S17.470 $97,600 $173,772 $23,270 $494,830 $14,845 $49,484 S74,226 334,639 $49,484 $123,710 $14,845 S850.O71 £4681.400
B E 17TH AVE OUTFALL $035,630 $129,069 $244,000 5494,616 $46,560 $1,799,875 $53,996 S1799B8 $269 901 £125,991 £179908 £449,968 £53.996 S3, H3.704
c E RICHTHOFEN PL OUTFALL 5142,044 £13,701 S97.600 $140,712 $16,440 £411.207 £12,339 S41.130 £61,695 £20,791 £41,130 S103,024 512,339 $711,545
440104 A S ALTON ST IMPROVEMENTS $175,440 S51 266 $73,200 $00,496 $10,950 $391,352 £11.741 $35 135 $58,703 327,395 $39,135 [7,833 $11,741 $677,040 £14 046.203
B E MISSISSIPPI AVE DETENTION $975 000 $975,000 £29,250 $97,500 £146250 368,250 £97,500 $243,750 £29.250 51,686,750
C S HAVANA ST OUTFALL 54,612,557 $332,029 $505,600 51,177,444 £45,210 £6,752.840 £202 505 £675,204 £1.012 926 £472,6 £675.204 S1,606,210 £202,565 511.682,413
450001 A E 33RD AVENUE SYSTEM $6,603,596 $677,159 $1,561,600 $2,649,996 £233,250 $11,730,601 £351.313 $1,173,060 $1,759,590 $821,142 $1,173,060 3^,932,650 $351,918 $20,293,939 S67 090.422
B 36TH STREET SYSTEM $670,326 $151,729 3244,000 5422,604 836,970 51.525.625 $45,759 £152,563 £225.844 £106,794 £152,563 £331,407 S45.769 52.639.33S
C 40TH AVENUE SYSTEM 53,776,509 $668,028 $1,506,000 £2,202,252 £349,030 56,601.819 £256,055 £060.102 S1.2S0 273 £602,127 £860,102 £2,150,455 £250,055 514,381.148
D CITY PARK SYSTEM $1,707,771 $336 425 £005,200 $1,154,000 £121,070 $1,425,000 $5,550,266 $106,508 $555,027 $832,540 $388,519 $555,027 $1,387,586 $166,508 $9,601,961
E HIGH STREET SYSTEM 33,560,135 $182,462 $683,200 $1,080,340 $95,860 $5,602,047 $168,061 £560,205 $840307 $392,143 5560.205 £1,400,512 £168,051 59,691.541
F JACKSON STREET SYSTEM $460,854 £111,476 £266.400 S365.248 $88,970 $1,294,958 £36.849 $129,496 £194.244 $90,647 £129,496 £323.740 £39.349 £2,240.279
G 26TH AVENUE SYSTEM $690,371 $106,496 £390.400 $667,440 $115,000 SI .977 707 S59.331 $197 771 $296,656 $138,439 $197,771 $404,427 359,331 $3,421,433
H E 19TH AVENUE SYSTEM S939.332 $159,671 $536,800 $774,040 $87,670 $2,497,563 $74,927 £249,756 3374,534 $174,629 £249,756 SK24.391 S74.927 $4,320,703
4500-02 A MARION STREET SYSTEM PHASE 1 51,276,377 $116,407 £195.200 $320,732 817.810 £1,928.525 £57.856 £192.853 £209 279 £134,997 £192.053 £482,132 £57.856 $3,336,352 £50,339294
B MARION STREET SYSTEM PHASE 2 33.413.279 $268 204 £463.000 $921,933 $60,250 S5.132.265 $153,908 $513.226 $769,840 S359.259 $513,226 31,283,086 $153,968 $8,878,318
c E 24TH AVE SYSTEM 51,333,195 $350,522 $878,400 81,091,804 $135,550 $4,289,471 $128,684 -$428,947 $043,421 $300,25? £428,947 £1,072,360 $120,684 S7.420 705
D CITY PARK WEST DRAINAGE IMPOVEMENTS 53,604,406 $606,682 $1,586,000 52,137,228 £294.310 £8.228,828 £246.865 £822.883 S 1.234.324 £576,018 £822.003 £2,057.207 $246,865 £14,235,873
E E 12TH AVE IMPROVEMENTS $541,395 SE5.887 £050,800 $642,444 $258,620 S2.187 146 $65,614 $218,715 $328,072 $153,100 $218,715 3546 786 S65.614 $3,783,702
K N MARION ST LATERALS $409,035 S52.460 $390,400 $436,940 £61.610 £1.400 511 £42.015 £140,051 £210,077 £90,036 £140,051 £350,120 $42,015 £2,422,004
L E33RDAVE LATERALS 52,136,526 $416,446 $1,342,000 51.745 268 3288.870 $5,931,110 £177.933 £593,111 5989.666 £415,178 £593,111 £1.482.778 $177,933 £10,260,820
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Denver Storm Drainage Master Plan
September 2014
STATEMENT OF PROBABLE COSTS IN 2013 DOLLARS
PROJECT HARD COSTS INDIRECT COSTS TOTALS
COLLECTOR SYSTEM ID PROJECT PIPE MANHOLE INLETS ASPHALT PATCH WET UTILITY RELOCATE DETENTION TOTAL CONSTRUCTION COSTS TRAFFIC CONTROL (3%) MOBILIZATION / DEMOBILIZATION (10%) DESIGN & ENG IN EE RIM G (15%) materials MANAGEMENT (7%) CONTRACT ADMINISTRATION t CONSTRUCTION MANAGEMENT (10%) CONTINGENCY (25%) environmental compliance (3%) TOTAL TOTAL BY COLLECTION SYSTEM
4500-03 A 16TH AVENUE SYSTEM S5.21D.444 5174.033 $707,600 SI. 200.616 395,870 S7 388,563 £221,657 £738,856 £1,100,284 £517.109 $738,856 £1.847,141 3221,657 £12,782,213 $43 363.416
B GLENCOE STREET SYSTEM 36,098,457 $347 566 £976.000 £1.839,756 S239.610 S9,501.309 S265.042 £950.139 $1,425,200 $865,097 $950,139 £2 375.347 £285,042 S16.437.403
C MONACO STREET SYSTEM $4,397,399 $609,792 £1.122 400 $1 824 196 $221,020 $8,175,607 $245,268 $817 561 $1,226,341 $572,292 $817,561 $2,043,902 3245,263 $14,143,800
4500-04 A JACKSON STREET SYSTEM S3,283,045 5199,330 $463,600 $704,712 £79,430 $4,736,117 £142,004 £473,612 £710,418 £331,528 £473,612 £1,184.029 3142,084 S3.193,484 $01,571,195
B HALE PARKWAY SYSTEM 35,238,017 3196.732 $629,600 S1.561.312 S317.520 $8,163,131 5244,095 £016,318 $1,224,477 $571,423 $016,313 £2.040.795 £244,895 S14 122,302
C 8TH AVENUE SYSTEM -$4,108,167 $596,465 $1,024,600 S1.533,346 $167,080 $7,429,880 S22Z8&5 $742 986 $1,114,402 $520,092 $742,968 $1.857.470 $222,096 $12,853,692
D KRAMER IA STREET SYSTEM 34,010,347 S6B8.232 $1,317,600 $2,040,592 $193,050 $0,249,021 3247.495 £024,902 $1,237,473 $577,437 SB24.902 $2,062,455 $247,495 $14,272,190
E GRAPE STREET SYSTEM 33,096,322 3432,379 S8QS.2Q0 S1.369.6S0 S268.240 $5,991,031 5179,755 £599,103 £890,775 £419.428 $599 103 S1 497 968 5179,755 510,365,600
F JACKSON STREET SYSTEM LATERALS S1.SS4.260 $410,43B '$1,024,800 £1,548,728 £306,610 35,254,845 £157,645 £525 484 £700,227 £367.839 $525,484 £1,313,711 S157,645 £9.090.880
G COLORADO BOULEVARD SYSTEM 33,275,566 $619,926 $1,171,200 $1,037,004 £321,610 $7,325,306 £219,759 $732,531 51,093,796 $512,771 $732,531 $1,831,326 5219,759 $12,672,779
4*00-01 A STOUT ST OUTFALL 52,049,040 3246.875 31.317.600 S1 425,492 5106,210 $5,225,217 5156,757 $522,522 £783,703 $365 765 $522 522 S 1.306,304 £156,757 59,039.627 £63,347.951
B CHERRY CREEK OUTFALLS 34,353.892 $496,419 £1.537,200 £2 079,532 £407,820 $8,874,913 £266,247 5887.491 £1,331,237 £S21,244 £887 491 £2,218,728 £266,247 £15.353.598
c W 14TH AVE EXTENSION 3350,954 835.145 5244, QUO S347.112 331,490 31,000,701 $30,251 51D0.B70 5151,305 $70,609 SI00,070 5252,175 S3D.261 £1,745,052
D W8THAVE OUTFALL $406,554 £78,731 $244,000 8369,576 $31,510 $1,132,371 S33.371 S113.237 $169,056 £79.266 $113,237 $203,093 S33.971 $1,959,002
E W9TH AVE OUTFALL $507,677 £76.229 $366,000 $491,130 £43,840 31.884.926 £56,548 £108.493 S202.739 £131.945 £138.493 £471,232 £56,548 33,280.924
F WEST COLFAX AVE OUTFALL 82.456,051 $334.167 51.049 200 SI 705.704 £191,690 $5,736,812 £172,104 $573,681 5&G0.522 $401,577 $573,601 S1.434.203 £172,104 $9,924,684
G CURTIS ST OUTFALL 82.757,458 $424,743 £1.653,200 $1,889,715 $305,250 $7,036,356 $211,001 $703,637 $1,055,455 $492 546 $703,537 $1,759,092 $211,091 $12,172,915
H N BANNOCK ST IMPROVEMENTS £454 341 $103,391 3414.800 SdS9,196 £43,830 $1,505,558 £45,167 £150 556 £225.834 £105.389 £150.556 5376,390 £45,167 32,604.617
i N SPEER BLVD IMPROVEMENTS $73,910 $15,086 S146 400 396.472 535,500 5371,440 £11,143 S37,145 555,717 526,001 $37 145 $92 862 £11,143 £642,604
J W 13THAVE EXTENSION 81,133.556 $213,075 8438200 8554.696 $80,770 $2422107 $72,663 S242.211 $363,316 $169,547 $242,211 5605.527 $72,653 $4,190,245
L W 11TH AVE IMPROVEMENTS 8546,392 £104,614 8292,800 £414.216 $58,070 $1,410,092 $42,567 £141.009 $212,034 $99,322 $141,659 $354,723 $42,567 52,454,603
4600-02 A DOWNING ST OUTFALL 31,781,347 $371 053 31.266 800 51.742.800 $164,200 $5,320,200 S159.040 5332,020 S7S9 242 $372,900 $532,028 51.332,070 3155.648 S9,217,924 £68,015.612
B LAFAYETTE ST OUTFALL LATERALS $336,916 $68,405 $341,600 8361,782 549,280 $1,157,983 $34,739 $115,790 $173,607 $81.053 $115,790 5289.496 $34,739 $2,003,309
c E 5TH AVE OUTFALL 81.952.770 $313,905 $1.073 600 £1 1S2.746 $09,050 £4,622,073 5135,662 $462,207 5593,311 $323,545 $462,207 51.155,516 £135,662 $7,996,185
D E 6TH AVE OUTFALL 51,015,562 3168122 $406 000 $623,152 S58.8B0 $2,353,716 570 611 5235,372 $353 057 $164 760 $235,372 S560.429 570,611 $4,071,920
E E CEDAR AVE $274,955 $49,691 $202,800 5344 476 $39,690 $1,001,612 $30,048 $100,161 S150.242 $70.113 $100,161 5250.403 $30,04S $1,732,780
G E EXPOSITION IMPROVEMENTS SI, 545.4TQ $323,000 S054.OOO £1 237,650 $202,640 54,163,670 £124,910 $416,367 3624,550 $291,457 5415,367 SI .040.916 £124,910 $7,203,149
H COLORADO BLVD 31,160,273 3136.169 £610 000 $806,260 S69.B30 $2,702,532 583,476 5270 253 $417 300 $194 777 $278,253 $695. S33 S33.476 $4,813,780
1 N UNIVERSITY BLVD OUTFALL £416,457 $148,519 $512,400 $446,528 £39,710 $1,563,014 £40,508 £156,361 £234,542 £109.453 £156.361 £390,904 £46,906 32,705.051
J 5TH AVE IMPROVEMENTS $354,548 $115,324 5317,200 £343.900 £23,290 $1,154,270 $34,628 $115427 $173,140 $60,799 $115,427 5286.566 £34,620 51,906,007
K 8AYAUD OUTFALL S6.945.416 $254,933 $2,025 200 S2 365.820 $353,280 $12,444,649 $373,339 $1,244,465 $1,066,697 $071,125 $1,244,465 S3.111.162 3373,339 $21,529,241
L Iff- UPGRADES £717,290 $120,678 $927 200 SS77.0SG £150,540 £2.742.988 £82;2S0 £274,299 £411.448 £152.009 £274,299 £685,747 £82:2M 34,745,370
40OCKJ2-1OOYR (street depth ntena) A E 4TH AVE OUTFALL 86,205,903 SKG.193 8707,600 $7299786 £209.510 $0,952,994 £265.590 $895,299 S1.342.349 $626,710 3895,299 S2.230.240 3258,590 £15.400,679 S15.408.S79
4000-03 A E EXPOSITION AVE OUTFALL 81,662,581 £431.294 $1.439600 $1 710.216 £294,320 $5,530,011 $166,140 $553,601 £030,702 5387.661 $553,801 £1.304.503 £165,140 59,530,759 $37.029 014
B S HOLLY ST OUTFALL £335,446 £43.711 5317 200 S436 676 $27,400 51,210,433 £35.313 $121,043 $161,565 $04,730 5121,043 £302.606 $36,313 S2.094,048
D S HONEY WAY OUTFALL £235,481 £32.767 $244,000 $270,348 £12,330 £794.946 £23,848 £79.495 £119,242 £55.646 £79 495 £198,736 £23,648 31,375.256
E E FLORIDA AVE OUTFALL 33,418,940 $101 164 3512 400 $1 140,552 $97,190 $5,350,246 $160,507 $535.025 $802,537 $374,517 $535,025 $1.337.562 3160.507 $9,255,926
F S ONEIDA ST OUTFALL $51,380 $11,090 $73,200 $84350 84,110 3214,130 56.424 521.413 S32.120 S14.9B9 $21,413 $53,532 56,424 $370,445
G S VALE DR OUTFALL 897,945 $15,905 £122.000 S127 844 $9,590 5373,204 £11.199 $37 320 £55,993 £26 130 S37 32B £93.321 £11,199 S645.702
H JEWELL AVE OUTFALL $294,589 564.354 8268.400 $257,272 $10,960 $895,585 $26,853 £39.558 5134.333 $62,691 $09,553 $223,896 $26,858 $1,549,362
i S NIAGARA ST OUTFALL 84.320.139 $221,306 8029,600 $1,554,904 £101,310 $7,027,419 £210.823 $702,742 $1,054,113 $491,919 $702,742 $1,756,855 3210,823 $12,157,436
40CM3-1GDYR C TENNESSEE & ONEIDA STORM DRAIN 34,070,222 5100,027 3610.000 S1 154.386 £80,790 $6,015,427 £204,463 S6B1.543 $1,022,314 £477.080 56B1 543 S1.703.657 3204,463 311 790,690 £11 790 690
46OD-04 A iff* UPGRADES £264.385 $64,406 $468,000 $345,092 £20,550 $1.182.433 £35,473 £118.243 £177 365 £32.770 $118,243 £295,608 £35,473 £2.045,603 $4,961,467
E DARTMOUTH AVENUE OUTFALL $074,209 $170,698 8244.000 $305,600 $10,960 $1,685,467 $50,564 $160,547 5252,620 $117,903 3168,547 S421.367 $50,564 52,915,059
4601-01 A 1BT UPGRADES S707.590 3106.674 3634 400 3750,200 S119.070 S3,317,934 569.530 5231.793 $347,090 $162,255 £231.793 S579 484 S69.538 $4,010,025 S12.141.S64
B E ILIFF AVE IMPROVEMENTS £758.851 $142,495 £317.200 £568.036 £23,290 S1.B0S.B72 £54,256 £180,987 $271431 £126,601 $180,987 £452,468 £54,256 £3,131.078
C S MONACO STREET PKWY IMPROVEMENTS $229,274 $23002 8145 400 £225.852 $2,740 $620,060 $18,042 $62,607 £94,210 $43,965 $62,807 $157,017 $18,842 $1,086,550
D S TAMARAC DR IMPROVEMENTS $734,661 S111.359 $317 200 5462.304 $90.350 $1,705,874 $52,976 $176,587 $264,001 $123,611 $176,507 5441 463 $52,970 $3,054,960
E E DARTMOUTH AVE IMPROVEMENTS £216,369 $69,101 £73.200 $125,556 £12,330 £496,556 £14,897 £49,656 £74.483 $34,759 £49,656 $124,139 £14,397 £655,043
4700-01 8 N WOLFF ST OUTFALL £29,640 S31B1 $24,400 £30,586 $4,110 $100,019 $3,001 $10,002 $15,003 £7,001 $10,002 525.005 $3,001 $173,034 S16.637. BOO
C1 * W 16THAVE IMPROVEMENTS * 81.761.757 $68,068 $414,800 8772.956 $116,390 $3,133.971 $94,019 $313,397 $470,096 $219,370 $313,397 5783 493 $94,019 $5,421,770*
C2 W 17TH S 16TH AVE IMPROVEMENTS £165.775 $25; 448 £195 200 3216,380 £31,450 £634.293 £19,029 £63,429 £95.144 £44,401 £63.429 $158,573 £19,029 31,097,327
D- W COLFAX AVE IMPROVEMENTS * 33,129,472 363,400 S3416O0 3770.000 553,410 $4,370,682 $131,360 5437,868 £655,802 $306,500 $437,068 S1 094,670 3131.360 $7,575,118
E W LAKESHORE CR IMPROVEMENTS $354,395 $38,172 $292,800 8414.544 $17,810 $1,117,721 $33,532 $111,772 $167,653 S7S.240 $111,772 S27S. 430 $33,532 $1,933,657
F W 26TH AVE IMPROVEMENTS S6S.030 £32.620 S73.200 $75,776 $2,740 £252,424 £7,573 £25.242 $37,064 $17,670 525,242 $63,106 £7.573 £436.694
470001-1O0YR A SLOAN'S LAKE 1Q0-YR OUTFALL 56,635,379 362.232 $408,000 S1.24O.SS0 $125,960 $6,572,279 $257,160 5857,228 £1,205,842 £600,060 $857,228 S2.143.070 3257,168 $14,030,043 £14.630,043
4600-01 A N STUART ST IMPROVEMENTS $640,596 $79092 $122,000 8253.000 $41,060 $1,136,556 $34,097 $113,656 $170,403 $79,559 $113656 5204.139 $34,097 S1.966.243 $8,595 513
c 1ET UPGRADES £478,030 $96,664 5707.600 £559.736 £160,110 52,002,140 £60,054 $200,214 $300,321 £140,150 £200,214 £500.585 £60,054 53,463,702
D N WOLFF ST IMPROVEMENTS SB63.984 3110.056 $317 200 S4G7.36B £71,200 $1,029,600 554,094 5102.901 £274,471 $128,007 $182,901 S457 452 £54,894 $3,165,560
490CHD1 A N YATES ST IMPROVEMENTS £186.195 £45,352 $170,300 $213,324 £13,700 £029.371 £18,801 S62.CG7 £94,406 £44.056 £62.937 £157,343 £13,381 31,088,612 £4,948,095
B S JULIAN ST OUTFALL 3510,568 £103.320 S244.QOO £393.000 £42,450 51,293,346 £30.600 £129,335 5194.002 $90,534 £129,335 £323.336 £30.600 52,237,400
E W EXPOSITION AVE IMPROVEMENTS $110,535 314.109 £97 600 $133,512 516,440 5372,196 511,166 $37,220 £55,029 £26.054 $37,220 £93.049 S11.166 £643,000
F W 1ST AVE OUTFALL £193,206 £19.167 S122.000 5203,032 £27,380 £565,605 316,960 S56.56Q SS4.341 £39.592 356.560 £141.401 S16.&60 £978,405
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Denver Storm Drainage Master Plan
September 2014
STA TEMENTOF PROBABLE COSTS W2011 DOLLARS
PROJECT HARD COSTS INDIRECT COSTS TOTALS
COLLECTION STSTEM ID PROJECT PIPE MANHOLE INLETS ASPHALT PATCH WET UTILITY RELOCATE DETENTION TOTAL CONSTRUCTION COSTS TRAFFIC CONTROL (3%) MOBILIZATION 1 DEMOBILIZATION (10%) DESIGN & ENGINEERS G (15%) MATERIALS MANAGEMENT (7%) CONTRACT ADMINISTRATION / CONSTRUCTION MANAGEMENT (10%) DON TING ENGY (25%) ENVIRONMENTAL COMPLIANCE (3%) TOTAL TOTAL BY COLLECTION SYSTEM
5OD0-Q1 A 16" UPGRACES 51.137 110 $248,274 $1,366,400 $1,349,368 5109.560 £4.210,732 $126,322 £421,073 $631,610 $294 751 $421 073 $1,052,683 $126,322 $7,284,566 $18.439,886
B CENTER AVE COLLECTION $1.978.354 $9,000 S122 000 331.510 £2,140.864 £64.226 £214,086 £321130 £149 860 S214.0B6 3535.216 £54.226 £3,703,694
D ALAMEDA AND SANTA FE OUTFALL S116,279 $23,016 £146,400 $120,640 $2,740 -$409,275 $12,278 £40,928 $61,391 $26,646 £40.928 $102,319 $12,278 £706.045
E S GRANT ST COLLECTION S278.900 S23.802 5146,400 $254,076 S12 33G S725.508 $21,765 S72.551 $1 OB 826 $50,786 $72,551 S1B1.377 $21,765 $1,255,129
F SOUTH BROADWAY IMPROVEMENTS SI 487 074 S215.415 3536,800 $727,056 $56,170 $150,000 S3.172.515 $95,175 3317,252 $475,877 $222,076 $317,252 $793,129 S95.175 35,438,451
5000-02 A DAHLIA ST AND ASBURY AVENUE 8606,333 592,170 £403,600 $614,776 346.500 $1,823,459 $54,704 $182,346 £273.519 £127.642 £182.346 $456,865 354,704 £3,154.565 317,570.255
B MEXICO AVENUE $206,785 S2B.C64 £210500 £242,012 £27.400 £723,831 £21,715 £72,383 S1QB.575 £50.658 £72.383 $160,958 £21,715 $1,252,226
c SOUTH HIGH SCHOOL DETENTION S4.448.351 $182, £G3 $292,000 $435,852 $42,450 $1,125,000 36,527,386 $195,022 $652,739 $979,100 $456,917 $652,739 £1631.046 3195,022 $11,292.379
D 10" UPGRADES $248,900 567,619 S341.600 5324.S0O S98.540 $1,081,539 £32.446 $108,154 £162,231 $75,708 £108.154 £270,385 $32,446 £1,871,063
500003 B E IOWA AVENUE EXTENSION $110,885 $9,543 $73,200 $128,752 $27,380 £349,760 £10,493 $34,976 £52.464 £24 483 £34.976 537,440 $10,493 $605,085 £10,307.235
c E MISSISSIPPI AVENUE S LOGAN STREET LATERAL $446,612 $61.969 S244.000 $403,660 $19,180 $1175,421 $35 263 3117,542 $176,313 $02,279 $117,542 $293,055 335.203 $2,033 476
D 16" UPGRADES S151 145 $39,744 $292,000 $197,284 $47,910 $728,883 £21 666 S72.88B $109,332 $51 022 $72,088 $182 221 £21,866 $1,260,966
E SUB-BASIN 600 IMPROVEMENTS $143,980 $7,369 £151,349 $4,540 £15,135 £22.702 £10,594 £15,135 537,837 £4,540 $261,832
G S WASHINGTON ST DRAIN (100 YEAR ONLY) 52.207.800 $253,798 3414,800 $671,700 £50,693 $3,593,788 £107,904 $359,879 £539.018 £251.915 S359.B79 5899,697 £107.964 $6,225,904
510001 A 16" UPGRADES $616,360 $156,290 $1,073,600 $804,512 $35,620 $2,696,382 £80.691 £263,638 $404,457 $186,747 $269,638 $674,096 $80,891 $4,664,740 $61,558,837
B SCARLANST OUTFALL 3564,866 5166,206 3390,400 $599,968 $46,530 $2,160,100 $65,045 $216,010 $335,215 $151767 $216,010 $542,025 305,043 $3,750,013
C S DECATUR ST OUTFALL $584,537 $46,848 £292,000 $533,464 $58,170 £1,493,919 £44,610 $149,392 £224.008 £104,574 £149.392 £373.480 £44,610 £2,584.481
D S FEDERAL BLVD OUTFALL 5811 132 $122,812 $292,000 $562,168 $86,250 $1,875,162 £56.255 $187,515 $261,274 $131,261 $187 516 $468 790 $56,255 S3 244 029
E W MISSISSIPPI AVE IMPROVEMENTS S3.510.125 3407.250 3805,200 $1,700,204 $197,120 $0,619,899 $190,597 3061,900 S992.985 S463.393 $061,950 31,654,975 3193,597 S11.452.426
F S QUITMAN ST IMPROVEMENTS 5115.920 $23,053 £170,000 £129,024 £23.293 $462,087 £13.663 S4G.209 £69.313 S32.346 S40.209 £115,522 £13,663 £799.412
G S TEJON ST OUTFALL $269,652 $50,326 $97,600 3190.992 $12 330 $620,000 £18,627 362,090 $93,135 $43,463 $62,090 $155,225 $18,627 $1,074,157
H S TENNYSON ST IMPROVEMENTS S3.258.636 $117,970 $1,000,400 $1,656,544 $165,710 $6,199,310 $185,979 3019,931 $929,096 $433,952 $619,931 $1,549,028 3105.979 $10,724,006
I S UTICA OUTFALL SS43.145 $46,076 5219.600 3510,048 $52 020 $1780,839 £53.427 5176,089 $267 133 $124,662 $176,035 $445,222 £53,427 $3 000,938
J S VRAIN ST OUTFALL $608,035 $118,101 £512.400 3721.464 $39 730 $1,099,730 £59,992 £199,973 £269,960 £139.981 $199,973 $439,932 359.S92 S3.45S.533
K S XAVIER ST OUTFALL 3236,814 $25,549 S17O,B0O $279,028 $26,030 $738,221 S22.147 $73,822 $110,733 S51.675 $73,822 $104,555 S22.147 $1,277,122
L W JEWELL AVE IMPROVEMENTS $972,034 £177 157 $244,000 3456.512 $78,010 S1.027 713 £57 631 5192 771 S289.157 $134940 $192,771 $481 928 $57,831 £3,334.942
M W KENTUCKY AVE IMPROVEMENTS $1,131,410 £201.927 £439 200 3828.120 £53,430 $2,654,087 579,623 £255,405 £390,113 £185.785 £265,409 $663,522 £79.623 34.591 572
it HARVEY PARK LAKE OUTFALL $274,144 $226,300 £13.700 $514,224 515.427 $51,422 £77.134 £35996 £51 422 $123,556 $15,427 58 B0.6GB
0* MISSISSIPPI GULCH INTERCEPTOR S3 681.452 $12,626 $122 COO £16.440 $3,832,518 $114,076 5383,252 $574,878 $268276 $363,252 $958 130 £114,976 $6,630,258 *
510001-10UYR A * W MISSISSIPPI AVE LATERALS * SI. 151 182 $290,598 3512.400 $825,880 $113,610 $2,893,670 386.810 S289.3S7 £434 050 $202,557 $289,367 $723,418 $86,810 S5.006.O4S * 321.6S1 382
B * W MISSISSIPPI AVE IMPROVEMENTS * S3.689.526 $247,567 3390.400 31,313,600 $171,000 55,812,183 $174,365 £581.216 £871,827 £406.053 £581.210 31,453,046 3174.365 £10.055,075*
o MISSISSIPPI GULCH INTERCEPTOR S3 681.452 $12,626 S122 000 £16 440 S3.832.518 $114 976 5383,252 $574,678 $268,276 S383 252 S95S.130 5114,976 S6 630.258
5200-01 B E WARREN AVE EXTENSION $354,306 $44,835 3170,800 $258,288 323.290 3851,519 $25,546 $85,152 $127,720 359,006 S85,152 $212.SS0 S25.546 $1473.129 £35 644.500
E BROADWAY RELIEF. WESLEY TO HARVARD (1QOYEAR ONLY) $551,230 S7.200 $97,600 $150,200 $15,070 $830,300 $24,909 $83,030 £124,545 $58,121 503.CG0 S207.575 £24.90S 31.436.41S
F DELAWARE TRIBUTARY (SOUTH OF EVANS) $174,470 $18,263 S122.000 3175.416 £32,860 £523,009 $15,690 £52,301 £78,451 £36.611 $52,301 £130,752 £15,690 S904.S05
G DELAWARE TRIBUTARY (SOUTH OF HARVARD) $300,958 $86,000 $195,200 $229,012 315.070 3820,240 S24.7S7 $82,024 $123,936 $57,837 S82.624 $200,560 $24,707 $1429,395
i EVANS OUTFALL $215,954 $67,392 $97 600 $147,532 $27,360 $555,858 $16 676 $55,586 $83,370 $38,910 $55,586 $138,964 $16,676 $961,835
J EVANS TRIBUTARY (EAST OF BROADWAY) £754.811 $75,785 £366,000 $663,236 $75,330 £1,035.162 £58,055 $193,516 £290.274 £135.461 5193.516 3483,790 $58,055 $3,347,623
K GAL^PAGO TRIBUTARY (SOUTH OF EVANS) $128,653 $11,115 $73,200 $132,016 $15,050 $360,034 $10,801 $36,000 $54,005 $25,202 $36,003 $90,008 310801 £022.857
M GALAFAGO TRIBUTARY (SOUTH OF WESLEYj 3206 795 $14,524 $122,000 $105,856 S3,740 $451,915 $13,557 $45,192 367 787 $31,634 $45192 $112,979 $13,557 $781,813
o HARVARD GULCH OUTFALL PRELIMINARY REPORT S12 220.960 $55,481 £414,800 £47,456 £63.570 312,822,267 $384,666 £1,282,227 31.923,340 S397.559 31,282.227 $3,205,557 $384.6S8 522,102,523
p ROSE DALE PARK DETENTION 31 447,500 $1,447 500 $43,425 £144,750 £217,125 £101325 £144,750 £361.875 $43,425 £2,504,175
520002 A COLUMBINE OUTFALL $22 230 $4,064 $24,400 £29,016 $5,480 S85 190 $2,556 $0,515 S12.778 S5.963 SB.51S $21.208 $2,556 $147,379 $39,004,016
B CORNELL TRIBUTARY (FLOWS TO ENGLEWOOD) $69,635 $12,724 397,600 $109.59(2 58,220 S317.7M 59,533 $31,777 S47 666 $22,244 $31777 $79,443 39.533 5549,744
C DARTMOUTH TRIBUTARY (FLOWS TO ENGLEWOOD) £54.005 S9.543 S73.200 S64.692 $27,360 $229,030 96.872 £22,900 S34.362 S10,030 £22 908 £57.270 36,572 3396,300
D DRY GULCH MAJOR OONDUIT $2 283.166 $23,859 £195,200 3355,568 $30,120 £2.897.915 $86,937 $289,792 S434.687 £202.854 £289 792 S724 479 $86,037 $5,013,393
E FLORA TRIBUTARY (FLOWS TO ENGLEWOOD) $314,102 $42 102 5292,300 3341,59(2 $52,020 51,042.610 S3127S S104,262 $156,392 $72,983 $104,262 $260,654 S31.278 $1003,725
G GAYLORD OUTFALL (NORTH OF HARVARD GULCH) £50,025 £7,747 £48.800 £55,580 $4,110 £166.362 £4.091 £16.636 £24.954 £11,645 S16.636 £41,590 £4,991 $287,805
1 HARVARD GULCH PARK TO RACE $12,275 540 $54,676 £435,200 360,260 312,833.676 S385.010 $1,283,368 31.925.051 S8S8.357 31.283.366 $3.208,41S $385,010 £22.202.259
J CORONA OUTFALL 3178.366 $26,234 3195 200 $210,508 $9,590 5619.950 $18,599 361.996 £92.994 $43,397 $61,996 $154,990 318.599 $1,072,529
K JOSEPHINE OUTFALL 317,290 S4.064 $24,400 $22,568 35,480 £73,802 S2.214 $7,360 SU070 £5.196 37,-300 S10.45O $2,214 $127,676
L LAFAYETTE OUTFALL (NORTH OF HARVARD) $767,824 S233.894 £439.200 3474.440 $62,990 $1,978,348 $59 350 £197.835 £296.752 $133,484 £197 835 3494 587 £59.350 S3.422 541
M LAFAYETTE OUTFALL (SOUTH OF HAFWARD) $60,135 $0,543 $73,200 £78.492 $1.370 $222,740 SO 682 $22,274 333.411 £15.592 £22,274 £55.665 36.0S2 $385,340
N PENNSYLVANIA OUTFAUl $22,310 $1,365 324,832 S4 110 $52,637 $1,579 $5,264 $7 896 £3,695 $5,264 $13,159 $1,579 $91,063
O RACE OUTFALL $71 085 $9,543 $73,200 SS4.672 35,480 $243,980 $7,319 $24,398 $36,597 £17 079 S24.338 £60.995 £7.319 £422,005
p UNIVERSE OUTFALL (NORTH OF HARVARD GULCH) $375,118 $91,602 3292,300 $325,717 $23,290 £1,108,527 $33 256 $110,853 £166.279 £77.597 £110.853 £277.132 £33.255 $1,917,753
s WILLIAMS OUTFALL 362.700 $9,543 S73.200 S01.84C S6 850 £234,133 S7.GG4 $23,413 £35.120 $16,306 $23,413 S58 533 S7.024 $405,049
T YORK OUTFALL $138,032 $19,187 £122.000 $152,872 $6,850 S438.941 31S. 168 $43,394 $65,841 $30,726 $43,894 3109.735 313.100 S759.307
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Denver Storm Drainage Master Plan
September 2014
ST A TEM ENT OF PROBABLE COSTS IN HOT 3 DOLLARS
PROJECT HARD COSTS INDIRECT COSTS TOTALS
COLLECTION SYSTEM ID PROJECT PIPE manhole INLETS ASPHALT PATCH WET UTILITY RELOCATE DETENTION TOTAL CONSTRUCTION COSTS TRAFFIC CONTROL (3%) MOBILIZATION 1 DEMOBILIZATION (10%) DESIGN 8 ENGINEERS G (15%) MATERIALS MANAGEMENT (7%) CONTRACT ADMINISTRATION / CONSTRUCTION MANAGEMENT (10%) CONTINGENCY (25%) ENV TON MENTAL COMPLIANCE (3%) TOTAL TOTAL BY COLLECTION SYSTEM
5230C3 A AMHERST OUTFALL S154.904 $19,035 $122,000 $152,592 $12,330 $461,661 $13,050 $40186 see. 249 S32.316 $46,166 $115,415 $13,850 £798,673 £59,028,108
AA STEELE OUTFALL $147,160 $23,940 $146,400 $149,820 $12,330 $479,650 $14,390 $47,965 $71,948 $33 576 $47,965 £119,912 $14,390 $829,796
B BIRCH OUTFALL 3395.771 $72,417 $292,800 S334.320 S30.14Q 51,125,448 $33,763 $112,545 $168,817 573,731 $112,545 £281.362 S33.703 51,947.024
BB YALE OUTFALL (COLORADO TO BIRCH) $1,169,003 *12,600 $170,000 $201,724 $36,970 $1,591 097 $47 733 $159,110 $238,665 $111 377 $159 110 $397,774 $47,733 £2.752 593
C CLAYTON OUTFALL (SOUTH OF HARVARD GULCH) $634,975 $123,774 $414,800 $513,354 $102,690 $1,849603 $55,480 $184,960 $277,440 $129 472 $164,960 £462.401 $55,488 S3,199.812
cc YALE OUTFALL (BIRCH TO CLERMONT) 3251,241 £1,800 324,400 $46.812 56,850 $331,103 $9,933 $33,110 $49,0 523,177 533,110 582,776 59,933 $572 807
D CLAYTON TRIBUTARY (SOUTH OF AMHERST) 5347.450 $125,390 $292,000 $304,888 $34,240 $1,104,760 $33,143 $110,477 $165,715 $77 334 $110,477 £276,192 $33,143 $1 911.249
DD YALE OUTFALL (CLERMONT TO BROOK) $397,546 574,072 $471,618 $14149 $47,162 £70,743 $33,013 £47,162 S117.904 £14,149 £815,900
E CLERMONT OUTFALL $1.059.516 $216,975 $683,200 $825,084 S64.39Q 32,653,165 505,595 S2B5.316 5427 975 5199,722 5285,316 $713.291 555,595 54,905.975
EE YALE OUTFALL (BROOK TO DENNISON) 5383.420 $3,600 $48,000 $71,440 $8,220 $515,480 $15 464 $51,546 $77 322 $36,084 $51 548 £128 870 $15,454 S391 780
P COLORADO OUTFALL (NORTH OF HARVARD GULCH) S1,700,623 $315,767 $558800 $936.848 $113,630 $3,725,660 $111,770 $372,567 S556.850 $260,797 S372.567 £331.417 £111,770 36.445,406
FF YALE OUTFALL (DENNISON TO QAHLLA) $477,596 $3,600 546,300 $95,312 $5,460 5630,703 $10924 563,079 S94.516 $44,155 S63.079 $157,697 S1B.S24 $1 091,264
G COLORADO OUTFALL (SOUTH OF HARVARD GULCH) $612,094 $62,760 $439,200 $537,160 $83,510 $1,834,744 $55,042 $183,474 $275,212 $128,432 $183,474 S45S.6B6 $55,042 £3.174 106
GG YALE OUTFALL (DAHLIA TO EUDORA) $340,218 $20,066 sas.aoo $81,720 sio,&eo £517,754 £15,533 351,776 £77.665 $36,243 £51,776 £129.441 £10533 $895,731
H COOK OUTFALL $477,395 $130,525 $195,200 $270,904 560,220 $1,134,244 $34 027 $113,424 $170,137 $79,397 $113,424 £283,561 334,027 $1,962,241
i DAHLIA OUTFALL $235,174 $27,769 $170,000 $220,720 $15,070 $669,533 $20,086 $66,953 $100,430 $46,067 $66953 $167 383 $20,006 $1 158,291
II YALE OUTFALL (GLENCOE TO HUDSON) S392.063 580,233 $146,400 S1S3.B52 $10,960 5313,528 524.406 381,353 5122,029 556,947 581 353 5203,382 S24.406 $1,407,404
J DARTMOUTH TRIBUTARY 5611,263 $07,385 $610,000 $^4,724 $69,030 $2,010222 $60,397 $201,322 $301,983 $140926 $201 322 3503,306 £60,397 £3.482.875
K ADAMS WAY IMPROVEMENTS $95,006 $15,868 $97,600 $93,588 $1,370 $303,432 S3 103 530,343 $45,515 $21,240 $30.343 $75 858 $9,103 £524 337
L DENNISON OUTFALL 5124,939 $18,263 $122,000 5130,300 53,220 S403,722 S12.112 540,372 S60,558 S2B.261 540.372 5100,930 312,112 5693,439
M EASTMAN TRIBUTARY (EAST OF FOREST) $1,210,909 $324,171 $707,600 $776,950 $117.820 $3,145,430 $94,363 $314,543 $471,014 $220,180 £314,543 £786.350 594.363 SS. 441.594
N EUDORA OUTFALL $2,051 521 $206,910 $406,000 $838,816 $73,900 33.659.227 $109,777 $365,923 $548884 $256146 $365,923 $914,807 £109,777 S6.330.464
P GLENCOE OUTFALL (SOUTH OF YALE) 5278,478 $35,703 $219,600 5253,416 531,510 5323,707 524.711 582,371 5123.556 S57.659 582.371 5205,927 S24.711 $1,425,013
Q GLENCOE TRIBUTARY (SOUTH OF HIGHLINE CANAL) S033.492 $208,295 $439,200 $620,524 $76,680 $2.170191 $65,346 $217,619 $326,729 $152,473 £217,819 $544,548 £65,346 £3.763,271
u JACKSON OUTFALL (NORTH OF HARVARD GULCH) $109,445 $14 109 $57,600 $120,704 $4,110 $344,968 $10,349 $34,497 $51,745 $24148 £34.497 $86 242 $10,349 S596.795
V JACKSON OUTFALL (SOUTH OF HARVARD GULCH) S68.8S5 S7.747 543,800 $76,672 56.350 5208,954 56.269 520,895 531,343 514,027 $20,895 352,238 $6,20a 5361.490
w MANSFIELD TRIB. (FLOWS TO CHERRY HILLS VILLAGE) $157 664 S32.559 $215,500 $164,632 $23,290 £597,945 517.S36 S59.7&4 $89,692 $41 056 $59,794 $149,486 $17,938 $1 034 443
X MONROE OUTFALL $102,037 $16,006 $97,600 $105 032 $10,960 $331,635 $9,949 $33,164 $49,745 £23.214 £33,164 S82.909 $9,949 S573.729
5300-01 A 18" UPGRADES S24,8S0 $29,447 348,600 532,483 S135,625 $4069 513,562 S20.344 39,494 S13.562 333,906 $4,069 $234,631 SB. 155,027
B S FEDERAL BLVD IMPROVEMENTS $515,287 $157,981 $341,600 $449,000 538320 $1,502,188 545.066 5150,219 $226,328 $105,153 $150,219 $375,547 £45,066 £2.598.786
C S 2LINI ST OUTFALL $1,144,235 $234,102 $534,400 $1,014,480 $49,320 $3,076,537 $92,296 $307,654 $461,481 $215,358 S307 654 $769,134 £92.296 $5 322.410
550M1 A 10" UPGRADES S230.565 $30,172 $292,600 $300,940 $10070 $077,555 $26,327 $87,756 $131,633 $61,429 $07,756 £219,369 826,327 $1,518,172 S7.407 582
B S KNOXCT UPGRADE $110,034 $57 638 $48,800 $55,784 $2 740 $275,796 S8.274 $27,530 $41,369 £19306 $27 580 £68.949 $8,274 $477,128
C S UTICA ST IMPROVEMENTS $415.430 $72,403 373,200 $160,044 532.660 £753,667 £22.913 376,307 $114,580 £53,471 S763B7 $190 967 £22,916 $1,321,491
D W AMHERST AVE IMPROVEMENTS $447,450 $60,439 $463,600 $584,040 $69,850 $1,625,379 $40761 $162,538 $243,807 $113,777 $162,538 $406345 $48,761 $2,811,905
F VRAIN ST IMPROVEMENTS $240330 $106,570 $122,000 $162,900 $79,360 5739,240 522.177 $73,924 $110,886 S51 747 $73,924 5164,810 $22,177 £1.278,385
550CM32 A 18" UPGRADES 5107 730 $28,629 $219,800 5140.616 52.740 5459,315 514.979 $49,902 $74,397 S34.952 S49,932 5124,829 $14,979 ^63.815 £13,346,391
B S NEWLAND ST OUTFALL 5513,691 $53,998 $341,600 $467,596 $46,580 $1,423,463 $42,704 $142,346 $213,519 £99.542 $142,346 £355,866 $42,704 $2,462,500
C S SHERIDAN BLVD OUTFALL $1,115,389 $153,237 $585,600 S949.640 $86,230 $2,891,096 $86,733 $289,110 $433,664 S202 377 $289,110 S722J74 $86,733 $5,001,597
D S WEBSTER ST OUTFALL 51,211,210 $33,548 $386,000 3485.360 S52.020 $2,168,138 S65.044 £216,814 5325 221 $151,770 5216.814 $542,034 $65,044 $3,750,879
E W BATES AVE IMPROVEMENTS $147,935 $48,533 $195,200 $174,382 $9,590 $575,640 $17,269 $57,564 $86,346 S40.295 S57.564 $143,910 £17,269 £095,657
F W DARTMOUTH AVE IMPROVEMENTS $44,965 $6,362 $48,800 $50,048 $6,850 $157,025 $4,711 $15,702 S23.554 £10.992 £15.702 £39,256 $4,711 £271,653
5500*04 A S WADSWORTH WAY IMPROVEMENTS $614,608 $04,506 $146,400 5259 008 531,470 51,035,992 331,000 S10Q.5SS 5155,399 $72,519 $103,595 $253,998 '$31,080 $1792,266 $4,172,615
B GLENBROOK DETENTION BASIN & S GARRISON ST IMPROVEMENTS $402,076 $266,430 3390,400 $272,928 $23,290 31,375,924 $41,278 $137,592 $206,389 $96315 $137,592 $343,981 £41,278 $2,380,349
550005 A FOOTHILLS GC IMPROVEMENTS $1,055.777 $15,905 $122,000 $140,740 $1,370 $1,335,792 $40,074 $133,579 $200,369 $93,505 $133,579 S333.948 $40,074 S2 310.920 S3.478.670
B FOOTHILLS GC IMPROVEMENTS 01 $45,000 $45,000 $1,350 54,500 36,750 $3,150 $4,500 $11250 51,350 $77,850
C FOOTHILLS GC IMPROVEMENTS 02 $90,000 $90 000 S2.70Q $9,000 $13,500 £6,300 S3.000 $22,500 $2,700 £155,700
D S HARLAN ST DETENTION 01 $30,000 $30,000 $900 $3,000 $4,500 $2,100 S3.000 £7,500 S900 $51,900
E S HARLAN ST DETENTION 02 $45,000 $45 000 $1,350 54,500 36,750 33,150 $4,500 $11,250 51.350 $77,850
F S HARLAN ST DETENTION 03 $150,000 $150 000 S4.500 $15,000 $22 500 $10,500 $15,000 $37,500 $4,500 $259,500
G S PIERCE WAY DETENTION 5315 000 £315.000 $9,450 $31,500 $47 250 £22.050 £31,500 £78.750 $9,450 5544,950
Projects shown vuth an asterisk are excluded frown the Recommended Plan m favor a? the Alternative shown for that collection system
Page
[sj


Denver Storm Drainage Master Plan
4.0 STUDY REFERENCES
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Page 26


Denver Storm Drainage Master Plan
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Gingery Associates, Inc. Flood Hazard Area Delineation Sanderson Gulch & North Sanderson
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International Business Center Filing No. 8, August 1999, Revised January 7, 2000.
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Basin, October 5, 1989.
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Platte River Confluence to Sheridan Boulevard, Engineering Assessment and Maintenance Master
Plan, January 2002.
ICON Engineering Inc., Weir Gulch Inventory and Rehabilitation Plan, May 2004.
September 2014
ICON Engineering Inc., Dry Gulch Outfall Systems Plan, May 2013,
J.F. Sato and Associates. Coots Field Phase 2, Offsite Drainage Basins Plan Sheet. March 1994,
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Drainage Report, May 2008.
Kiowa Engineering Corporation, Academy Park Tributary to Bear Creek Outfall Systems
Planning Study, December 1997.
Kiowa Engineering Corporation, Academy Park Tributary to Bear Creek Outfall Systems
Planning Study Preliminary Design Report, July 1999,
Kiowa Engineering Corporation, Upper Weir Gulch Major Drainageway Planning Study -
Alternative Development and Evaluation, October 1992.
Kiowa Engineering Corporation. Second Creek and Direct Flow Area 0053 Outfall Planning Study,
Preliminary Design. May 1990.
Kiowa Engineering Corporation, Pinehurst Tributaiy to Bear Creek Outfall Systems Planning
Study, Preliminary Design Report, December 1999.
Kiowa Engineering Corporation. Globevilie-Utah Junction Watershed Outfall Systems Planning
Study Preliminary Design Report. February, 2000.
Kiowa Engineering Corporation, Westerly Creek (Lower) Drainageway Update, Hydrology Report,
December 2008.
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Drainageway Planning, Phase A Report, June 2009.
Kiowa Engineering Corporation, Westerly Creek (Downstream of Westerly Creek Dam) Major
Drainageway Plan tot the Urban Drainage and Flood Control District & Denver & Aurora, July
2010.
Kirkham, Michael and Associates, Master Storm Drainage Study, Fairlake Development, Revised
March 1994.
Kirkham, Michael and Associates, Quincy Lake Phase III Drainage Report, June 2003,
Landmark Engineering, Ltd., Final Drainage Report on Stormwater Quality Control Plan,
Gravesite Development and Cemetery Improvements, Fort Logan National Cemetery, December
2003.
Love & Associates, Inc., Prairie Gateway Outfall Systems Planning Alternative Evaluation Report.
August 2002,
Love & Associates, Inc., Prairie Gateway Outfall Systems Planning Preliminary Design Report,
April 25. 2003.
Page 27


Denver Storm Drainage Master Plan
Martin/Martin, Inc. Revision to the First Creek and DFA 0055 Outfall Systems Master Plan
(Picadiily Road to Buckley Road). November 18, 1998.
Martin/Martin Consulting Engineers, Denver International Airport Drainage Master Plan Part
Three Analysis of Full Development Plan, Final Report June 2004.
Martin/Martin Consulting Engineers, Union Pacific Realty Company Property, Phase IVand V,
Irondale Gulch Basin Drainage Plan, January 6, 1994.
Martin/Martin Consulting Engineers, Gateway Park Parcel IV West Irondale Gulch Basin Drainage
Pian, October 8, 1996.
Matrix Design Group, Inc., 40h/40h Storm Drain Outfall Report January 2008.
Matrix Design Group, Inc., Federal Boulevard Storm Sewer Improvements Preliminary Drainage
Report, October 2008.
Matrix Design Group, Inc., Gulch Master Plan for the City and County of Denver, October 2009.
Matrix Design Group, Inc., Harvard Gulch Outfall Alternatives Analysis and Feasibility Study
Preliminary Engineering Report fox the City and County of Denver, May 2010.
Matrix Design Group, Inc., North Stapleton Infrastructure Master Plan, Approved December 2006.
Matrix Design Group, Sanderson Gulch Major Drainageway Plan, April 2013.
Matrix Design Group, Sanderson Gulch Major Drainageway Plan and Flood Hazard Area
Delineation, for the Urban Drainage and Flood Control District, September 2013.
MB Consulting, Inc., Single Tree atDIA Filing §2 Master Drainage Plan, December 18, 1998.
McLaughlin Water Engineers, Ltd., Stormwater Outfall Systems Plan Stapleton Area, July 1995.
McLaughlin Water Engineers, Ltd. South Platte River Central Platte Valley: Alternative
Evaluation and Preliminary Design Report. December 1989.
Merrick and Company, Flood Hazard Area Delineation Westerly Creek, March 1983.
Merrick and Company, Outfall Systems Planning, Westerly Creek East of Havana, October 1996.
Merrick and Company. Urban Drainage & Flood Control District Denver, Glendale, Arapahoe
County: Flood Hazard Delineation Cherry Creek. July 1976.
Merrick and Company, Harmon, and ODonnell & Herminger Associates, Inc. Major Drainageway
Plaiming Cherry Creek. May 1977,
Merrick and Company, Harmon, O'Donnell & Henninger Associates, Inc., and Alan M. Voorhees
& Associates, Inc, Master Plan for Cherry Creek the Phase "A" Study Report. July 30, 1976.
September 2014
Moser & Associates, First Creek (Upstream of Buckley Road) Major Drainageway Plan:
Conceptual Design Report for the Urban Drainage and Flood Control District, August 2010.
Moser & Associates. Irondale Gulch Outfall Systems Plan Conceptual Design Report for the Urban
Drainage and Flood Control District, September 2011.
Moser & Associates, Upper Goldsmith Gulch Outfall Systems Plaiming Conceptual Design Report
for tlie Urban Drainage and Flood Control District, November 2005.
Moser & Associates, Upper First Creek Baseline Hydrology Report, May 2009,
Muller Engineering Company, Inc. First Creek Master Plan Adjustments, September 30, 2004.
NelsoinHaley-Patterson & Quirk. Montbello Storm Drainage, Preliminary Design. Vol. II -
Drawings. May 1975.
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Drainage and Flood Control District, April 2010.
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Pardue, Cornwell & Associates, Inc., Majestic Commerce Center, Irondale Gulch Basin Master
Drainage Plan, April 8, 1998,
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2008.
PB Americas Inc., Hydrologic and Hydraulics Report for Kennedy Ball Fields Outfall. July, 2010.
PBS&J, 27h & Federal Stormwater Master Pian (Basin 006F01, 006 F02). April 2005.
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Page 28


Denver Storm Drainage Master Plan
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March 1982.
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Evaluation Report Planning of Holly Hills Area Tributary to Harvard Gulch Outfall Systems. April
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November 13, 2000.
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September 2014
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Tributary; May 1978.
URS Company, Flood Hazard Area Sloan s Lake Basin, October 1977.
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Basin Area, Phase B Preliminary Design, August 1979.
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March 1977.
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Alameda to 0h Avenue, October 2009.
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Denver Storm Drainage Master Plan
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Gulch to Mississippi Avenue) Phase B Preliminary Design, June 2004.
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WRC. Outfall System Planning Four Square Mile Area. August 1985.
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Design Report. February 9, 1990.
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Preliminary Design Report. May 1990.
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Metropolitan Area Sand Creek to Oxford Avenue September 1985.
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Baseline Road, Phase B, 2 Volumes. November 1985.
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Collection System Page
0058-01 35
0059-01 37
0060-01 39
0060-02 43
0061-01 45
0061-02 47
0062-01 51
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006-1-01 55
0061-02 57
0065-01 59
0065-02 61
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4500-01 115
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4600-04 133
4601-01 137
4601-02 139
4700-01 141
4800-01 145
4801-01 145
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5000-01 149
5000-02 151
5000-03 153
5100-01 155
5200-01 159
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5200-03 163
5300-01 165
5401-01 167
5500-01 169
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5500-03 173
5500-04 175
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5501-01 179
5901-01 181
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Denver Storm Drainage Master Plan_______
This page left intentionally blank.
September 2014
Page 32



Q
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6TH AVE
1ST AVE
ALAMEDAAVE
EXPOSITION AVE
MISSISSIPPI AVE
FLORIDA AVE
JEWELL AVE
ILIFF AVE
YALE AVE
' DARTMOUTH AVE
HAMPDEN AVE
MANSFIELD AVE
QUINCY AVE
UNION AVE
BELLEVIEW AVE
DRAINAGE BASINS WITH
AREAS OF CHANGE
DENVER STORM DRAINAGE MASTER PLAN
CITY AND COUNTY OF DENVER
Legend
interstate
Collection System Boundary
BiuePrint Denver Area of Change
City & County of Denver Boundary
Page 33


Denver Storm Drainage Master Plan
Basin 0058-01 (Prairie Gateway)
Existing Basin Description:
This collection system basin is a tributary to the South Platte River and is located in Denver and Adams
Counties north of Stapleton, The basin consists of about KOI I acres, the northern portion which consists of
the Rock)- Mountain Arsenal.
The basin was loosely defined in Denver's 1989 Master Plan and included a portion of north Stapleton (south
of 56lh), as well as the Postal Facility and Adams County (north of 56lh). Basin 4400-01 includes all area
south of 56lh Avenue in accordance with the approved Drainage Master Plan for the Stapleton
Redevelopment site, dated March 2001. Therefore, the resulting basin lies north of 56Lh Avenue.
Although most of the land in this basin is within Adams County, it is included in this Denver study for the
approximately 70-acre Denver Water Pump Station and Postal Facility. The surrounding area was previously
part of the Rocky Mountain Arsenal, but has been cleaned and transferred to the U.S. Fish and Wildlife
Service, which in-tum has transferred the land to Commerce City. This land is known as the "'Prairie
Gateway, which includes Dicks Sporting Goods Soccer Stadium.
The site was studied in detail by the Urban Drainage & Flood Control District, Adams County and
Commerce City in a report titled. "Prairie Gateway Outfall Systems Planning Alternative Evaluation
Reportdated August 2002, The report concluded that the 100-year storm could be retained on the site
rather than upsizing the storm drains through Commerce City to the South Platte River. There are many
existing natural depressions on die site that can contain die 100-ycar rainfall event, hi addition, the US Postal
Facility' existing retention basins contain the 100-year storm The Prairie Gateway report identifies the
maximum available storage for the Postal Facility as 10 7 acre-feet for the 30-acre parking lot. and 29.6 acre-
feet for the 31,7-acrc Bulk Mail Facility.
With the redevelopment of the Prairie Gateway site for the Dick's Sports Soccer Stadium, drainage east of
Quebec Street and north of 56th Avenue has been directed into two major regional retention basins widi
approximately 225 acre-feet of retention storage for the 100-year. 24 hour storm event. By agreement, these
retention basins discharge into the Rocky Mountain Arsenal between storms by controlled releases.
September 2014
Page 34


FILE: Gtyit |}u.i]ifctillJi:nverL)i3in[ji: ?014'uictiYe\appsWBpbookv2014_SDMP_MapbDok_No_T[>pD.mxd, Etyi9ftD1 A, chris_niar1in
69TH AVE
67TH AVE
64TH AVE
63 RD AVE
Commerce City
62 N DAVE
59TH AVE
58TH AVE
E 56TH AVE
Adams County
in
2
>
_i
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o
cn
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in
<
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in
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4400-01

\
I
1


Laefora
Lake
Southgate
Pond

3901-01
650
1,300
Feet
1 inch equals 1,300 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
Proposed Storm Pipe
UDFCD Study
Recommendations
w Proposed Pipe
Disconnect
Legend
-* Existing Storm Pipe
Designed Storm Improvement
-+- Existing Surface Flow
Significant Flooding Location
- i Proposed Detention
Basin
Existing Basin

Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
Em City and County Boundary
; Other Municipalities
|| ~ ~ J Other Counties
Basin 0058-01
Prairie Gateway
Denver Storm Drainage Master Plan
Page 35


Denver Storm Drainage Master Plan
Basin 0059-01 (Globeville Utah Junction)
Existing System Description:
This collection system basin consists of 2.602 acres (4,07 square miles) and is mostly built-out. 1-25
traverses the middle of the basin and 1-70 traverses the southern portion of the basin. The 1-25/1-70
interchange is within this basin.
Blueprint Denver shows much of the industrial area northeast of the 1-25/1-70 interchange as "Areas of
Change. The northern approximately one-third of the basin is within Adams Count}'.
Basin drainage is predominately west to cast, with eight major outfalls to the South Platte River. A ninth
outfall exists at 58th Avenue, in Adams Count}'. Rcnnick railroad yard, west of 1-25, intercepts a significant
amount of the basin drainage from the w est. 1-25 also is a barrier to the runoff due to the limited crossing
capacity and elevated design. The outfall systems south of approximately 1-70 have capacity for the major
storm (not including the railroad yard diversion). The capacities of the outfall systems north of
approximately 47lh Avenue vary from less than the 5-year flood event to approximately a 25-year event,
Constraints to drainage infrastructure in this basin include:
* Crossing the railroad yards west of 1-25
* Crossing 1-25
* Multiple large Metro sewers just west of the South Platte River
* The South Platte River west bank levee
Drainage Deficiencies:
Drainage and flooding problems in the Globeville Utah Junction watershed are primarily caused by
undersized infrastructure and a lack of drainage infrastructure. The existing drainage systems are typically
undersized for the 2-year event. The 2013 Globeville Utah Junction Outfall Systems Planning Study, by
CHM2Hill for the UDFCD, provides additional detail on drainage deficiencies throughout the basin The
OSP documented that the minor storm collection system for the western portion of the basin is the watershed
north of 1-70. However, the OSP also confirmed that in larger storm events inflow from the Sunnyside
Neighborhood south of 1-70 can enter the Globeville Utah Junction watershed from south of 1-70 in the
vicinity of Inca or Jason Streets. The trans-basin flow rates shown on the facing page are from die Globeville
OSP, not modeling documented in the Technical Appendix
For purposes of this Master Plan, a 100-year alternative is proposed for Basin 0061-02 to intercept this runoff
in the major storm and convey it south to the South Platte River, This improvement would prevent all flows
from south of 1-70 from entering the Globeville Utah Junction (0059-01) Basin
Potential Inundation Areas:
In a major flood. 1-25 creates a Potential Inundation Area at West 52nd Avenue and Bannock Street and a
Potential Inundation Area at West 43rd Avenue and Caliita Ct. Potential inundation is also possible around
the CDOT detention basin on the castsidc of 1-25, at 52nd Avenue and Broadway', and the area located at 5 Ist
Avenue and Washington Street because of topographic constraints. Theres also a Potential Inundation Area
in 1-70 at North Pecos Street. Potential inundation is also possible in a major storm event north and east of
the Argo Park detention basin located near East 49lh Avenue and North Logan Street, An updated 2-
dimensional analysis of Potential Inundation Areas for the Globeville Utah Junction basin was completed
September 21)] 4
for the Master Plan Update, by ICON Engineering. See the corresponding memorandum in the technical
appendix for additional information.
Proposed Capital Improvements:
The following drainage improvements have been identified by the OSP and are proposed to increase the level
of sendee to a minimum of 10-vear capacity
Project A: 48th Avenue Outfall (A)
The Project A improvement is sized based on the installation of the 100-year alternative (Project L) m basin
0061-02 (Highland Basin).This project includes upsized and new pipe along 48th Avenue and ultimately
discharges into the South Platte River, This project has major crossings at the Rcnnick Rail Yard. 1-25, Argo
Park, and Washington Street.
Project B: 48th Avenue Outfall < B)
Tins project includes a storm drain outfall along 47th Avenue from Pearl Street to the South Platte River
This outfall crosses the Denver Metro sanitary interceptor and will require the purchase of a new easement
along the outfall.
Project C: 48th Avenue Outfall (C)
This project includes a storm drain outfall from West 52ml Place and Kalamath. south along KaJamath to the
48Ul Avenue Outfall (A) storm drain.
Proiect E: 5 la Avenue Collection System
This project includes a storm drain outfall from the Rennick Rail Yard east along 5 Is1 Avenue to the South
Platte River.
Project J: Interstate 70 Outfall
This project includes a storm drain outfall from 43rd Avenue and Lincoln Street to the South Platte River.
Proiect L: 49th & Grant Detention Basin
This project is a proposed 3.2 acre-foot detention basin to be located at the southwest comer of 49th & Grant
Tlie UDFCD Globeville Utah Junction Outfall Systems Planning Study identified alternative sizes for a
10-year storm. 100-year storm, and the inclusion of water quality' treatment. The ultimate size and function
will be dependent upon land constraints. Refer to the 2013 Globeville Utah Junction Outfall Systems
Planning Study for more information.
Page 36


FILE: G:\cj is jirojrtcti'i IJeny iirDiairiags_2D14LicliYatappsWapboak\2014 SDMP _Mapbook.mxd, 8/1D/2G14, chris..martin
Legend
800
1,600
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,600 feet
Collection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Existing Storm Pipe -1 Proposed Detention I Existing Transit Line
Designed Storm I m prove men t Basin Existing Basin fjj"" _Jlj City and County Boundary
* Existing Surface Flow i 1 Potential Inundation ' Area Other Municipalities
Significant Flooding Location I Planned Transit Line f! ~ ~ 1 Other Counties
Basin 0059-01
Globeville Utah Junction
Denver Storm Drainage Master Plan
Page 37


Denver Storm Drainage Master Plan
Basin 0060-01 (1-70 & Colorado Boulevard)
Existing System Description:
This collection system basin includes a mix of industrial and residential land uses, and consists of T371 acres
(2.14 square miles), It is Hilly built-out with older neighborhood residential in the upper reaches and
commercial in the lower reaches. Blueprint Denver shows die region downstream (northwest) of Vasqucz
Boulevard as an Area of Change'. The upper reaches of Basin 0060-01 are shown as Areas of Stability"
All drainage from this basin outfalls to the South Platte River.
Runoff is conveyed through the basin primarily by the streets as surface flow, with several storm drain pipes
also conveying water to die north. Some of the stonn drain pipes terminate at the City limit or at the Park
Hill (Triangle) detention basin before runoff continues into Adams County and into the South Platte River.
This basin is served by two primary outfalls: a 42-inch diameter pipe along York Street, and a relatively
small open channel north of the Park Hill (Triangle) detention basin running along the Union Pacific and
Rock Island Railroads through Adams County,
This basin is situated at the bottom of several other major drainage basins. During major storm events, basin
0060-01 can potentially receive trans-basin surface runoff from a number of other basins, including Park Hill
4400-02. 0060-02, and Montclair 4500-01 (through 0060-02), A total of five trans-basin overland flow paths
are observed in this basin during the major-event. Three of these are inflows from basin 0060-02 at the
upstream (south) portion of the basin, and two are from basin 4400-02 at the southeast portion of the basin,
Specifically, inflows from 0060-02 occur along Brighton Boulevard and the BNSF Railroad: along the UPRR
near 1-70 and York Street; and across 1-70 at Fillmore Street. Inflow s from basin 4400-02 arc received from
the east along Smith Road near Forest Street and at the Park Hill Golf Course near 38th Avenue and Dahlia
Street. A portion of the w ater from 4400-02 continues to flow to the east along Smith Road and into basin
0060-02. while a portion overtops the UPRR and flows north in basin 0060-01 in a major stonn event.
Drainage Deficiencies:
The existing drainage system has capacity1 to convey less than the l-year stonn event to the outfall. Rainfall
runoff in excess of the storm drain capacity has a history of ponding in the sump and flat areas. Major
drainage problems have been experienced along the Smith Road corridor at Dahlia, along Vasqucz Boulevard
near Sand Creek, along York Street, and at the Denver Water Recycle Plant located in Adams County just
downstream of Denvers city limit. Specific drainage deficiencies include:
The existing Union Pacific Railroad (UPPR) right-of-way creates a major barrier for surface flow
and causes broad flooding of the Sw ansea Neighborhood.
Improved conveyance (storm drain) is needed in York Street upstream of Brighton Boulevard and in
the industrial zones upstream of Vasquez Boulevard.
Drainage deficiencies at the basins outfall to the South Platte River have been documented by
Enginuity for the Urban Drainage and Flood Control District in a report titled Park Hill (North of
Smith Road) Drainage Outfall Systems Plan, Conceptual Design Report. dated January 24, 2012,
A portion of the area included in this study lies in Adams County outside of Denver's boarders, but
Denver would be a cooperating partner for the outfall, shown as Project I. since it serves as the
primary outfall for much of Basins 0060-01 and 4400-02.
Potential Inundation Areas:
An extensive area of potential inundation has been identified within Basins 0060-01, 0060-02, and 4400-02.
related primarily to ponding behind railroad tracks, 1-70, and odier sumps in the lower portions of each basin.
September 2014
Proposed Capital Improvements:
Drainage improvements in these basins should be viewed primarily to achieve the minimum pcifonnancc
objectives for residential and commercial areas (2- and 5-ycar storm drain system capacities and street
conveyance in larger storm events) established for the Denver stormwater program, primarily due to the high
cost of retrofitting new stonn drain in existing streets Proposed capital improvements include:
Project F: Park Hill Phase VI
A new 5-year stonn drain system is needed in Dahlia Street. This proposed project will connect downstream
to the planned 84 Park Hill Phase V stonn drain at Dahlia St and Smith Road (currently in design) and
Project F1 upstream.
Project FI: Park Hill Phase VI1
A new 5-year stonn drain system is needed in Dahlia Street. Tins proposed project will connect downstream
to Project F at E. 38th Avenue and 4400-02 Project F2 upstream.
Project G: 50th Avenue Interceptor
A new storm drain system is needed in 50^ Avenue. This proposed project will connect to the existing Park
Hill Phase II stonn drain system at 50lh Avenue and Colorado Boulevard.
Project H: Columbine and York Upgrades
A 5-year storm drain system is needed in Brighton Boulevard from York Street, extending south in Brighton
Boulevard. York Street and Columbine Street.
Project 1: Riverside Outfall
A 100-ycar 9'x6' outfall stonn drain is proposed w ithin York Street from Brighton Boulevard to outfall to the
South Platte River. This proposed project would provide an outfali system for 0060-01-H upstream and serve
as an outfall for a portion of the major-event trans-basin flow s that this basin receives. This project w:as
proposed in the Urban Drainage OSP study.
Project L: N Colorado Blvd Improvements
This project includes die addition of storm drains in local roads to improve the interception of the minor
stonn events.
Project M: Milwaukee St Improvements
A new 24-inch storm drain is needed in Milwaukee St from 50th Avenue to 49"' Avenue.
Page 38


F1L£: G:\tjit j]iojitctii\IJ':nvc!rDrainngB_2D14'iictivn^ipp5WBpboDk^0D60-01 .mxd, 8/19^2014, Dbris_rnartm
650 1,300
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,300 feet
Collection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe -1 Proposed Detention I Existing Transit Line
Designed Storm Improvement t Basin Existing Basin City and County Boundary
Existing Surface Flow | 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line l! r Other Counties
Proposed Projects
F PARK HILL PHASE VI : $4,329,893
F1 PARK HILL PHASE VII : $1,408,272
G 50TH AVE INTERCEPTOR : $3,039,606
H COLUMBINE AND YORK UPGRADES : $3,377,858
I RIVERSIDE OUTFALL : $5,121,083
L N COLORADO BLVD IMPROVEMENTS : $2,239,669
M MILWAUKEE ST IMPROVEMENTS : $501,837
Basin 0060-01
I-70 & Colorado Boulevard
Denver Storm Drainage Master Plan
Page 39


Denver Storm Drainage Master Plan
September 2014
Basin 0060-01 (1-70 & Colorado Boulevard)
(Alternative 100-Year Basin)
Proposed 100-Year Alternative Capital Improvements:
Project F and F1: Park Hill Phase VI & VH
Storm drain alignments shown in die 100-year alternative from Projects F and F1 are the same alignments for
the minor storm, Pipe sizes have increased for the 100-year alternative in order to reduce surface runoff
depths in the street to 12-inches in the gutter in accordance with Denver street-depth criteria. This analysis is
based on the July 2011 Sand Creek (4400-02) and Upper Park Hill (0060-01, 4400-02 <£ 4500-01) Basins
Final Drainage Study by Atkins. See that study for additional alternatives.
Page 40


F 650 1,300
Feet
1 inch equals 1,300 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
| Collection System
Boundary
| Topographic Basin
Boundary
!*! 100-yr Sub-Collection
' System Boundary
! Thalweg
Legend
Proposed Storm Pipe 1 Existing Storm Pipe
-----Designed Storm Improvement
--- Existing Surface Flow | |
UDFCD Study
Recommendations
X
Proposed Pipe
Disconnect
Significant Flooding Location
-1 Proposed Detention
i-----' Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line fl_ r Other Counties
Basin 0060-01 100-yr Alternative
I Existing Transit Line J
Q City and County Boundary I-70 & Colorado Boulevard
1 Other Municipalities
Denver Storm Drainage Master Plan
Page 41


Denver Storm Drainage Master Plan
Basin 0060-02 (1-70 & York)
Existing System Description:
This collection system basin consists of 934 acres (1,46 square miles) and is fully built-out with older
neighborhood residential in the upper reaches and industrial in the lower reaches. The National Western
Stock Show grounds are located within this drainage basin. Blueprint Denver shows the industrial portions
of the basin as Areas of Change. Only the residential neighborhoods are shown as Areas of Stability. All
drainage from this basin outfalls to the South Platte River.
Intercepted stormwater is discharged to the South Platte River via at least 12 storm drainage outfalls,
However, the only one major (larger than 48inch) outfall exists at Race Court just upstream of the Burlington
Ditch headgate This outfall (Design Point 1549) locally drains 597 acres tributary areas discharging via a 78-
inch pipe and parallel 42-inch pipe which have a total capacity of about 410 cfs. Following the criteria of an
80% full flow pipe, the existing system has less than a 2-year level of sendee, w hereas current criteria
requires a 5-year level of service for commercial/industrial areas.
Constraints to drainage infrastructure in this basin include:
* Crossing a major rail switching yard west of Blake Street
* Crossing (-70
* Crossing the BNSF Railroad next to Brighton Boulevard
* An elevated section of the Metro Sewer, along the South Platte River, creating a wall barrier for
drainage
While this basin is locally served by several small storm drains with a master planned goal of conveying the
minor 2- or 5-year event, the basin also experiences pass through flow from other basins during a major
storm event. A total of four trans-basin overland flowpaths are observed in this basin during the major-event.
Three of these arc inflows from basin 4500-01 (Montclair) at the upstream (south) portion of the basin.
Specifically, inflows occur at the UPRR Intermodal Facility7 at 40th Avenue and High Street: at 40th Avenue
and York Street; and at the Market Lead just east of 40* Avenue and Madison Street. Additionally, one
inflow from basin 0060-01 (originally from 4400-02) flows west along Smith Road and the UPRR. and enters
this basin at the Market Lead west of Colorado Boulevard.
Some of this trans-basin major-event runoff continues through basin 0060-02 and enters basin 0060-01 at
various points. These locations include along Brighton Boulevard and the BNSF Railroad, along the UPRR
near 1-70 and York Street, and across 1-70 at Fillmore Street,
Potential Inundation Areas:
Hydraulic analysis shows areas around the National Western Stock Show Complex to be subject to potential
inundation during major storm events. These areas are located along the South Platte River Valley and at
localized areas and sumps. Redevelopment of the site would warrant drainage improvements in this area.
A second area of potential inundation in this basin is the result of overflow from Basins 4400-02 and 0060-
01. Runoff from these basins enters Basin 0060-02 along Smith Road and crosses 46th Avenue between N.
Clayton Street and N. Steel Street, and flow's overland back into Basin 0060-01. Alternative drainage
improvements in these basins may reduce the threat of potential inundation in this area.
Another area of potential inundation is the result of overland flow from the Montclair Basins (4500). Runoff
in excess of the pipe capacity will enter basin 0060-02 south of 1-70 near 40th Avenue and continue to flow in
September 2014
a northerly and northwesterly direction through the basin. Drainage improvements associated with CDOT's
proposed lowering and reconstruction of 1-70 will need to address this off-site runoff from Montclair. This is
currently being evaluated in the Montclair Outfall Systems Planning Study by the Urban Drainage & Flood
Control District (UDFCD), funded by die UDFCD and Denver.
Drainage Deficiencies:
The existing drainage system generally ponds water beyond a 2-year storm event, with significant widespread
areas of potential inundation expected to occur during a 100-ycar event.
Proposed Capital Improvements:
The trans-basin overland flows were not taken into consideration when sizing the proposed projects identified
herein. If upstream proposed projects are constructed, for the 100-year storm event, the trans-basin flows
will be intercepted by the proposed systems in each basin and there will be no more trans-basin flow.
Four major storm dram projects have been proposed in this basin to increase the level of service from a 2-
vear capacity to a 5-ycar capacity .
Project A: East 45Lh Avenue System
This project includes an extension of the lateral network south of 1-70. Currently7, stormwater is collected in
45Ul Avenue. These improvements extend the storm drains into 44th and 43rd Avenues,
Proicct B; North Brighton Boulevard Outfall
This project involves construction of a new outfall at a new location. There is no easy or obvious new outfall
route to die South Platte River; access is either restricted by 1-70 or the Stock Show complex. To maximize
the use of the existing pipe network, a new7 96-inch outfall has been proposed from York Street &- 45 th
Avenue, through die National Western Stock Show grounds to the South Platte River. Negotiations are
needed to obtain an easement fora new7 drainage outfall in this area, if the existing outfall is to remain
without replacement. Other minor outfall pipes also need to be upsized in order to improve the level of
service in the area.
Project C: North Race Street Outfall
Tliis project involves upsizing existing storm pipe north of 1-70. The railroad is a major barrier for
constructing new pipe in this area. There arc few roadway crossings of the railroad in the area. The 91-acre
area (sub-basin 520) northeast of Vasquez Boulevard and 1-70 is currently drained by an 18-mch pipe under
1-70 The proposed pipe follows anew alignment in 48th Avenue to avoid construction in the 1-70 corridor.
Project D: National Western Improvements
This project involves enlarging existing storm drain outfalls near 1-70. Specifically, a 30-inch outfall south of
1-70 (Design Point 610) is upsized to a 48-inch pipe, A 24-inch outfall north of 1-70 (Design Point 600) is
upsized to a 48-inch pipe. A 30-inch outfall north of 1-70 (Design Point 590) is upsized to a 54-inch pipe.
Preliminary design may consider parallel pipes for this project rather than complete replacement.
Page 42


F4L£: G:\t|ii |]icjtrct-b'iIJunvqrDisiringa_2D14^iclrvfl\appsWapbook\2014_SDMP_Mapbook.mxd, Stf! D/2014j chris.
Feet
1 inch equals 1,200 feel
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
I Existing Transit Line
E^l! City and County Boundary
| | Potential Inundation . ; Other Municipalities
I----1 Arpa * "
3 Other Counties
Area
Planned Transit Line
Basin 0060-02
1-70 & York
Denver Storm Drainage Master Plan
Page 43


Denver Storm Drainage Master Plan
Basin 0061-01 (27th and Federal)
Existing System Description:
The 27lK and Federal collection system basin is located in northwest Denver, The approximate boundaries of
the basin are W, 19'11 Avenue on the south {Sports Authority Field at Mile High Stadium). W, 34th Avenue on
the north, the South Platte River to the cast and a varying edge on the west primarily extending to N. Newton
Street, with some portions extending as far west as N. Wolff Street, The basin is comprised of approximately
1,42ft acres (2.23 sq mi) of fully developed area. The basin generally drains from west to east and has
multiple outfalls into the South Platte River.
The basin is composed of a variety of land uses including residential, parks, commercial and industrial land
uses. Much of the basin is residential with commercial areas primarily located along Federal Boulevard and
the 1-25 corridor.
Blueprint Denver shows the area within 'A mile of 1-25, bounded on the east by 1-25, W. 20th Avenue on the
south, and W. 33rd Avenue on the North as an area subject to change. The remainder (over three-quarters of
the basin) is shown as being an "Area of Stability".
All drainage from this basin outfalls to the South Platre River. Intercepted stormwater is discharged in over 9
separate storm drainage outfalls which cross under 1-25, ultimately discharging into the South Platte. Some
of the more major outfalls include:
50-inch pipe at W. 20,h Avenue and N. Bryant Street
48-inch x 72-inch pipe at W. 25th Avenue and W. Byron Place
5ft x 8ft box culvert at Central Street and 19th Street
Drainage Deficiencies:
In general, much of the existing system is undersized and does not adequately convey the 2-vear or 5-vcar
design flows. Storm drain infrastructure in this basin has undersized outfalls, incomplete networks of storm
drain laterals and is primarily composed of brick and clay pipe systems which do not meet Denver Public
Works current drainage criteria for size and/or material. Much of the system was previously a part of a
combined sewer system which has since been separated from the sanitary component.
The 27th and Federal basin lies on a relatively steep area on the side of the South Platte River Valley. As a
result, water tends to move quickly through the basin and generally does not produce areas of severe ponding.
However, there are two major flow paths within the overall basin that do see shallow overland flooding. This
shallow flooding is primarily contained in the streets when a stonn event exceeds the storm drain capacity
The two major flow paths are generally described as follows:
Beginning near the intersection of N. King Street and W. 27lh Avenue, traveling southeast to the
South Platte River on the eastsidc of Mile High Stadium.
Beginning near Irving Street and Speer Boulevard, traveling southeast along Speer Boulevard to 1-25,
Proposed Capital Improvements:
Drainage improvements in this basin are primarily recommended to achieve the minimum performance
objectives as described in Denver's Drainage Criteria; 2-year and 5-year systems for residential and
commercial areas respectively. To meet these requirements, most of the existing storm drain network will
need to be replaced. These improvements can be phased in smaller projects following the completion of the
major project components. Proposed capital improvements include:
September 2014
Construction of storm drains in local roads show n to improve interception of minor storm event
runoff and conveyance within neighborhoods,
Installation of four new outfalls under 1-25 at N, Bry ant Street and 19th Avenue; at N. Bryant Street
and W, 20th Avenue; at W. 23rd Avenue and N. Alcott Street: and at N. Zuni Street and W. Byron
Place;
Installation of major stonn drain interceptors connecting to the 1-25 outfalls.
Page 44


FILE: G:\cps |ii n
0 600 1,200
Feet
1 inch equals 1,200 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
| Topographic Basin
^ Boundary
Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
* Existing Storm Pipe -1 Proposed Detention I Existing Transit Line
Designed Storm Improvement t Basin Existing Basin f|J"" Jlj City and County Boundary
Existing Surface Flow i 1 Potential Inundation ' ' Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line 1 ~ ~ Other Counties
Basin 0061-01
27th & Federal
Denver Storm Drainage Master Plan
Page 45


Denver Storm Drainage Master Plan
Basin 0061-02 (Highland)
Existing System Description:
The Highland collection system basin is located in northwest Denver, The approximate boundaries of the
basin are W, 34th Avenue to the south, 1-70 on the north, the South Platte River to the east and a vary ing edge
on the west extending as far west as N. Perry Street. The basin is comprised of approximately' .909 acres
(2.98 square miles) of fully developed area. The basin generally drains from west to east and has multiple
outfalls into the South Platte River.
The basin is composed of a variety of land uses including residential, parks, commercial and industrial land
uses. Much of the basin is residential with commercial areas primarily located along Federal Boulevard, W.
38th Avenue, and the 1-25 corridor. Many areas have mixed commercial/retail space on street comers with
gas stations, convenience stores and other neighborhood retail outlets. The northeast comer of the basin is
composed of industrial and warehouse uses. This area is generally bounded by 1-70 (north) and W 44th Avc
(south) and N, Pecos Street (west) and the Rennick Railyard (east).
Blueprint Denver shows "Areas of Change' in the vicinity of W. 38th Avenue, just west of Federal
Boulevard. N. Inca Street, north of W. 38th Avenue, and W 44th Avenue, just east of Federal Boulevard. The
remainder of the basin is shown as being an "Area of Stability".
All drainage from this basin outfalls to the South Platte River. Intercepted stonnwater is discharged in over 5
separate storm drainage outfalls which cross under 1-25, ultimately discharging into die South Platte. Some of
the more major outfalls include:
* Double 8x8 box culvert and a twin 7.25' x 3,5' box culvert at W. 34ltl Avenue and N. Kalamadi
Street
60-inch x 84-inch pipe at W 38* Avenue and 1-25
24-inch storm pipe crossing under 1-25 at Inca Street draining a small local basin just w est of 1-25
A 36-inch and a 30-inch storm drain crossing under 1-25 just north of the Park Avenue overpass,
draining a small local basin on the west side of 1-25
Drainage Deficiencies:
Storm drain infrastructure in this basin has undersized outfalls, incomplete networks of storm drain laterals
and is primarily composed of brick and clay pipe systems w hich do not meet Denvers drainage criteria for
size and/or material. Much of the system was previously a part of a combined sewer system which has since
been separated from the sanitary component.
The Highland Basin lies on a relatively steep area on the side of the South Platte River Valley. As a result,
w ater tends to move quickly through the basin and generally does not produce areas of severe ponding.
However, there are five major flow paths within the overall basin that do see overland flooding in larger
storm events. This shallow7 flooding is primarily contained in the streets when a storm event exceeds the
storm drain capacity. The five major flow paths, identified as thalwegs, are generally described as follows:
* Along W. 47* Avenue from near N. Pecos Street, flowing cast to N Jason Street, then northeast
under 1-70 and entering the Globeville Utah Junction (0059-01) Basin.
* Beginning near 46* Avenue east of N, Jason Street, flowing south between N. Inca Street and the
UPRR/BNSF railroads towards the W. 38* Avenue underpass and 1-25/38* Avenuc/Park Avenue
West interchange.
September 2014
Beginning at the intersection of W. 44* Avenue and N. Zuni Street, flowing east in W. 44* Avenue
to N. Shoshone Street, then southeast to N. Inca Street between W. 36* and W. 37* Avenues, then
east and underneath 1-25 crossing the railroad, thence northeast through the BNSF railroad yard.
Beginning at the intersection of W, 4141 Avenue and N, Bry ant Street, flow ing southeast and
ultimately reaching die bank of stonn drain inlets at W. 34* Avenue and N. Kalamath Street.
Beginning at the intersection of W 36* Avenue and N. Alcott Street, flowing northeast to W. 38*
Avenue and N. Tcjon Street, then cast on 38* Avenue to N. Osage Street, and southeast towards the
bank of stonn dram inlets at W. 34* Avenue and N. Kalamath Street.
In general, much of the existing system is undersized and does not adequately convey the 2-year or 5-year
design flows. The storm drain system along N. Inca Street (W83-333A and W83-333B constructed from
1988 through 1994) was designed for tlte 2-3/4 year event and was constructed of concrete pipe, however, die
design frequency identified in diis study indicates the need for a 5-year system, dierefore this system is
undersized as well
The 2013 Globeville Utah Junction Outfall Systems Planning Study, by CHM2Hill for the UDFCD,
confirmed that m larger stonn events runoff from the Sunnyside Neighborhood south of 1-70 can leave the
Highland Basin (0061-02) from soudi of 1-70 in die vicinity of Jason Street and enter die Globeville Utah
Junction Basin (0059-01). The trans-basin flow rates shown on the facing page are from the Globeville OSP,
not modeling documented in the Technical Appendix.
For purposes of this Master Plan, a 100-year alternative is proposed for Basin 0061-02 to intercept this runoff
in the major storm and convey it south to the Soudi Platte River. This improvement would prevent all flows
from soudi of 1-70 from entering the Globeville Utah Junction (0059-01) Basin.
Proposed Capital Improvements:
Projects A-K
Drainage improvements in diis basin arc primarily recommended to achieve the minimum performance
objectives as described in Denver's Drainage Criteria Manual: 2-year and 5-year systems for residential and
commercial areas, respectively and allowing streets to convey runoff up to 12-inches deep in die gutter in
larger storm events, To meet these requirements, most of the existing storm drain network will need to be
replaced These improvements can be phased in smaller projects following the completion of the major
outfall project components. Proposed capital improvements include:
Installation of new outfalls under 1-25 at W. 34* Avenue and Lipan Street: and Park Avenue and I-
25
Installation of major stonn drain interceptors connecting to die 1-25 outfalls.
Construction of storm drains in local roads shown to improve interccpdon of minor storm event
runoff and conveyance within neighborhoods.
Page 46


FILE: G:V|is ]]i>:jifcti'IJi.,nvi!il)iaina!ja_2D1 iViactiva^appsWapboak\UD6f02.mxtl, 8^9/201 A, rhris_mar1in
Key Map


lit,
4309-01
n o'-
/
*
W 3STH AttE
Arqo
Park
4AF
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
The trans-basin flow rates are from
the Globeville OSP, not modeling
documented in the Technical Appendix.
--------------------------Ti
li
0061-01


Proposed Projects
A W 34TH/35TH AVENUE COLLECTION SYSTEM : $8,428,352
B W 34TH AVE AND LIPAN ST OUTFALL : $9,238,206
C 40TH AVENUE AND FEDERAL COLLECTION SYSTEM : $13,502,327
D 42ND AVENUE AND FEDERAL COLLECTION SYSTEM : $5,982,532
E W 46TH AVENUE COLLECTION SYSTEM : $4,819,774
F W 47TH AVENUE COLLECTION SYSTEM : $8,604,756
G CHAFFEE PARK INTERCEPTOR : $8,670,816
H FOX STREET OUTFALL : $8,233,456
I LOWER W 38TH AVENUE COLLECTION SYSTEM : $10,491,127
J LOWER INCA STREET COLLECTION SYSTEM UPGRADES : $8,191,813
K UPPER W 38TH AVENUE COLLECTION SYSTEM : $9,646,239
0 600 1,200
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,200 feel
a Col lection System
Boundary
| Topographic Basin
^ Boundary
Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
- Existing Storm Pipe
----Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
-1 Proposed Detention
t Basin
Existing Basin
|----1 Potential Inundation
'----' Area
I---- Planned Transit Line
I Existing Transit Line
ET1 City and County Boundary
' Other Municipalities
K ! Other Counties
Basin 0061-02
Highland
Denver Storm Drainage Master Plan
Page 47


Denver Storm Drainage Master Plan
September 2014
Basin 0061-02 (Highland)
(Alternative 100-Year Basin)
Proposed 100-Year Alternative Capital Improvements:
Project L: Northwest Subarea Interceptor Storm Drain
The January 2012 Northwest Denver Sub-Area Drainage and Transportation Study, by WH Pacific,
includes a no detention alternative (Alternative C) for a 100-ycar storm drain system on the east side of the
basin. This improvement includes installation of I27x6'RCB, and 84 to 120 RCP that generally follows
Jason Street from West 47Lh Street to the South Platte River. This improvement will prevent all flows from
entering die Globcville Utah Junction (0059-01) Basin. Proposed 10-year improvements within the
Globeville Utah Junction (0059-01) Basin account for this 100-year alternative preventing any flows from
traveling north of Interstate 70 or cast of Interstate 25
Page 48


FILE: G:\cjis- ]]i(>]ifct*1IJcnvi2iDiaina!5B_2D1 iVtacErva^appsWapbook\2014_SDMP_MapbciDk_1 OOYR.rrtxd, H/19/2014, chris_maFlin
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
The trans-basin flow rates are from
the Globeville OSP, not modeling
documented in the Technical Appendix.
0 600 1,200
Feet
1 inch equals 1,200 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
3 Col lection System
Boundary
Topographic Basin
^ Boundary
100-yr Sub-Collection
System Boundary
Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Le9end Basin 0061-02 100-yr Alternative
Existing Storm Pipe r--j Proposed Detention [ Existing Transit Line J
Designed Storm Improvement Existing Basin flT Cltyand County Boundary H j Q h 13 H Cl
Existing Surface Flow | | Potential Inundation . ; Other Municipalities
I--1 An* 1
~ Other Counties Denver Storm Drainage Master Plan
Page 49
Significant Flooding Location
Area
Planned Transit Line


Denver Storm Drainage Master Plan
Basin 0062-01/4500-02 (Lower Platte Valley)
Existing System Description:
These two collection system basins combined include a mix of industrial, commercial and residential land
uses, and include 2.856 tributary acres (4.46 square miles) The basin is fully built-out with older
neighborhood residential in the upper reaches and commercial in the lower reaches. This basin includes
Lower Downtown. Coors Field, rail yards, and a number of existing residential neighborhoods. It is
characterized by terrace topography in the upper portions of the basin and very flat outfalls near the South
Platte River. This condition results in inadvertent detention near the basin headwaters and surcharge of storm
drains in lower reaches,
Currently, most of the drainage (nearly 75% of the basin) outfalls through one 81-inch storm pipe at 36th
Street, with approximately L936 acres tributary to this one outfall. Tire existing pipe has approximately 476
cfs capacity but the hydrology indicates the flow will be over 1.000 cfs in a 2-ycar event, and 1,700 cfs in a
5-year event (design flow). There arc opportunities for regional water quality treatment off the existing 81-
inch pipe near the South Platte outfall since it currently can convey a A-inch rainfall (WQCV) over such a
large developed basin area.
Drainage Deficiencies:
The existing drainage system has less than a l-year capacity. Rainfall runoff in excess of the storm drain
capacity has a history of ponding in the sump and flat areas. Many of the existing storm drains surcharge out
the manholes during large storm events. Major drainage problems have been experienced in this basin,
particularly north of Coors Field.
During a major storm event, split flow conditions exist in the basin, whereby storm runoff is exported and
imported out and into this basin. For split flow condition, see the 31st Street dt 36th Street Outfall Study and
Concept Design Report, December 2012 by Wilson and Company',
Potential Inundation Areas:
Several areas of potential inundation have been identified within the basin, mostly in areas w here the streets
become very flat. The areas surrounding the intersections of 36* Street/Blake Street. 3151 Street/Blake Street.
32nd Avenuc/Marion Street, 17th Avcnue/Lafayctte Street, 16th Avenuc/Franklin Street, and 16*
Avenue/Clarkson Street have been identified as locations where 100-year inundation depths could reach up to
3-feet in depth during a 100-year event.
Proposed Capita] Improvements:
This basin requires improvements primarily to the outfall since the lateral network is currently extensive in
this basin. The outfall should have 5-year capacity7, whereas the lateral network through the residential areas
should have a 2-year capacity
The existing 81-inch outfall in 36th Street is undersized, and additional outfalls are needed to relieve the
burden on the existing pipe. Constructing two new outfalls in this basin will reduce the tributary area of the
existing outfall The 31st Street & 36ih Street Outfall Study and Concept Design Report, completed by
Wilson and Company in 2012, investigated several outfall alternatives within the basin, and the
recommendations from that report are reflected in this Master Plan. Thirteen major drainage projects are
proposed for this basin as described below:
September 2014
Project A: Marion Street System Phase 1 connects to the recently designed River North Outfall located in
33rd Street. The Phase 1 extension includes a new 102-inch pipe in Marion Street from 32nd Avenue to 29th
Avenue. The existing pipe will be cut and plugged to provide additional capacity in the downstream system
where the new pipe crosses the existing stonn pipe. Work on this project should begin at the outfall and
extend upward to improve the ievel of drainage service in the basin.
Project B; Marion Street System Phase 2 storm drain will continue up the basin with a 102-inch to 90-inch
pipe in Downing Street to 2151 Avenue.
Project C: East 24th Avenue System provides additional stormwater collection for the proposed trunk line in
Project B. It includes a 60-inch pipe in 24111 Avenue w'ith additional lines extending up to 20* Avenue and
Vine Street. This project also includes replacing existing small pipes with i 8-inch diameter pipes to meet
current drainage criteria, improve collection/conveyance and reduce maintenance problems.
Protect D: City Park West Drainage Improvements extends into the upper basin with an 84-inch to 36-inch
diameter pipe This project also includes replacing existing small pipes with 18-iuch diameter pipes to meet
current drainage criteria, improve collcction/convcyancc and reduce maintenance problems.
Project E: East 12th Ave Improvements include replacing existing small pipes with 18-inch diameter pipes to
meet current drainage criteria, improve collection/conveyance and reduce maintenance problems.
Project F: 27* Street Interceptor Phase 1 includes maximizing the use of the existing 108-inch pipe in the
Coors Field Parking Lot. Currently, the tributary area to the pipe is only 88 acres. The outfall will extend up
27* Street to Champa Street with a 96-inch pipe.
Project G: 27* Street Interceptor Phase 2 will continue upstream in 27* Street from Champa Street to
Washington Street and along Washington Street to 19* Avenue with a 90-inch to a 72-inch pipe.
Project H: 27* Street Interceptor Phase 3 will extend along Clarkson Street from 19* Avenue to 14*
Avenue with a 60-inch pipe transitioning down to smaller pipe up into the basin. This project also includes
up-sized laterals in 16* Avenue.
Project L 27* Street Interceptor Walnut/Market Lateral includes a new upsized pipe network in
Walnut/Market Street south of 27* Street.
Project J: 27* Street Interceptor Champa Lateral consists of a new' box and pipe network in Champa Street
south of 27* Street
Proiect K: North Marion Street Laterals proposes to replace the existing small stonn drams east of Project A
with 18-inch or larger pipes to meet current drainage criteria and reduce maintenance,
Proiect L: East 33rd Avenue Laterals includes a system to balance out the remainder of the basin tributary to
the existing outfall. A new 42-inch pipe at 33rd and Downing Street will disconnect the existing pipe in
Humboldt Street and convey runoff to the existing 81-inch pipe in Downing Street, which is being relived
with construction of the new outfall in 33rd Street. In addition, existing small stonn drains are proposed to be
replaced with 18-inch pipes to meet current drainage criteria and reduce maintenance.
Proiect M; Grant Street Storm Drain collects runoff from the existing storm drams in 9th and 10th Avenues at
Ogden Street and delivers runoff in a 5-year event to the 13* Avenue Extension project in Basin 4600-01
Tins project also includes upsizing the existing storm drain in Grant Street from IQth to 13th Avenue
Page 50


FILE: GAcjis ]]Kjitct*,ilJi.'nYi!rDiHinBgB_2D1 Vtac[rYf3^afip&'Maf>boak\UD62-G1._$500{12.rrtMJ, 0/19/2014, Dhri$_martin
Proposed Projects
A MARION STREET SYSTEM PHASE 1 : $3,336,352
B MARION STREET SYSTEM PHASE 2 : $8,878,818
C E 24TH AVE SYSTEM : $7,420,785
D CITY PARK WEST DRAINAGE IMPOVEMENTS : $14,235,873
E E 12TH AVE IMPROVEMENTS : $3,783,762
F 27TH ST INTERCEPTOR PHASE 1 : $8,086,632
G 27TH ST INTERCEPTOR PHASE 2 : $7,924,292
- H 27TH ST INTERCEPTOR PHASE 3 : $4,452,452
I 27TH ST INTERCEPTOR WALNUT/MARKET LATERAL : $1,988,101
J 27TH ST INTERCEPTOR CHAMPA LATERAL : $4,477,254
K N MARION ST LATERALS : $2,422,884
L E 33RD AVE LATERALS :$10,260,820
M GRANT ST STORM DRAIN : $7,652,395
Feet
1 inch equals 1,600 feel
Boundary
Thalweg
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
* Existing Storm Pipe
----Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
-1 Proposed Detention
t Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line
Basin 0062-01 & 4500-02
I Existing Transit Line
ncitndcBound,,, Lower Platte Valley and 36th & Downing
; Other Municipalities
n Other Counties
Denver Storm Drainage Master Plan
Page 51


Denver Storm Drainage Master Plan
Basin 0063-01 (Central Platte Valley)
Existing System Description:
This collection system basin consists of areas draining to the right bank of the South Platte River from
Bayand Avenue on the south to Speer Boulevard/Cheny Creek on the north and as far east as Logan Street.
This basin consists of L297 acres (2.03 square miles) and includes older neighborhood residential in the
upper reaches east of the railroad tracks and Santa Fe. and commercial in the iower reaches. All drainage
from this basin outfalls into the South Platte River. Intercepted stormwater is discharged via at least 32 storm
drainage outfalls, which are comprised mainly of local storm drains from 1-25 and adjacent properties. Some
of the existing larger outfalls include:
Bayaud Avenue outfall is 36-inch (54-inch upstream) with 344 tributary acres
3rd Avenue outfall is 54-inch with 214 tributary acres
6th Avenue outfall is 72-inch with 256 tributary acres
13lh Avenue outfall is 42-inch with 119 tributary acres
Colfax Avenue outfall is 36-inch with 39 tributary acres
El itch outfall is 48-inch with 44 tributary acres
The storm drain infrastructure consists of a random network of drains and laterals. Drainage from the basin is
constrained by the elevation of tire South Platte Riv er and 1-25, which generally reduces capacity and creates
sump or surcharge conditions during major storm events. The reach adjacent to the South Platte River
between 6lh Avenue and Cherry Creek was removed from the riverine floodplain by LOMR Case No. 12-08-
0474P, December 17, 2012 by the completion of the South Platte River Restoration improvements.
Drainage Deficiencies:
The existing drainage systems have capacities vary ing from a 1-vcar to a 5-year stonn event. Rainfall runoff
in excess of the stonn drain capacity has a history of ponding within the commercial and industnal areas
against the railroad and 1-25. Localized ponding occurs frequently at W. Ellsworth Avenue and N, Lipan
Street due to topographic constraints imposed by the existing railroad and 1-25.
The basin delineation is based upon the storm drain network. The only split flow situation in this basin where
the pipe flow contravenes the site topography is at the Elitches site. Runoff in excess of the 16'\4 box
culvert capacity at the Pepsi Center will flow from the Aurana Campus and the Pepsi Center area northwest
into Six Flags El itch Gardens.
Two major-event FLO-2D analyses identify the Potential Inundation Areas along Broadway, from Alameda
Avenue to 5* Avenue, and another at 10lh Avenue and Osage Street. The results were incorporated into the
Master Plan. A trans-basin flow of 58 cfs, from the 4600-01 Basin, at 10* Avenue and Osage Street, was
identified during a 100-year storm event.
Proposed Capital Improvements:
Blueprint Denver shows the majority of the basin {commercial areas) as Areas of Change". Only the
residential neighborhood cast of the railroad tracks between Alameda and 8th Avenue is shown as an "Areas
of Stability, a relatively small area of the overall basin. Difficulties in constructing additional or replacement
storm drains arc the crossing of the railroad and 1-25. CDOTs Valley Highway Logan to 6th Avenue
Record of Decision (ROD) dated June 2007, Section 4,9.1.4 Stoimwater Drainage, noted that Denver's
Storm Drainage Master Plan and subsequent drainage improvements should be considered with each phase
of final design for the Valiev Highw ay Project.
September 20i4
Proioct A: West 13* Avenue Outfall
This project includes replacing the existing 42-inch outfall with a new7 66-inch pipe to provide a 5-year level
of service. The enlargement of the existing system is carried up the storm drains along 13th Avenue The 13m
Avenue outfall is shown widi a lateral extension of a 54-inch storm drain further into the sub-basin for
connection by future redevelopment.
Project B; West 7* Avenue Outfall
The existing 72-mcb storm drain in 7* Avenue must be upsized to a 90-inch pipe to provide a minimum 5-
ycar level of service. An existing constriction occurs where a 60-inch pipe with 0.61% slope connects
downstream to a 42-inch and 48-inch pipe at 0.61%. This intermediate reach of pipe between Quivas and
Tejon should be replaced with a larger pipe (78-inch) for 5-year capacity
Proiect C: West Bavaud Avenue
The existing system has less than a l-year event capacity. The Bayaud Avenue outfall consisting of a 54-inch
pipe is proposed for replacement with an 84-inch pipe for a 5-year sy stem. At Galapago, the proposed pipe
jogs over to Ellsworth Avenue to preserve the existing trunk system upstream and extends to Logan with a
lateral extending south in N. Lincoln Street to provide additional stonn conveyance in this area,
Project D: West Ellsworth Avenue
A short 24-inch storm drain outfall in Ellsworth under 1-25 should be replaced with a 54-inch pipe to provide
5-ycar capacity, and eliminate frequent ponding at Ellsworth and Lipan caused by' blockage of the runoff by
tlie railroad and 1-25.
Proiect E: West Mulberry Place
A new 48x72 box culvert outfall is proposed in Mulberry' Place. This 60 acre area is currently served by 15
and 18-inch outfalls. Redevelopment of the area will prompt the construction of a new7 outfall.
Proiect F: West 3rd Avenue Outfall
A new 78-inch outfall is proposed to replace the existing 60-inch outfall in 3rd Avenue to achieve a 5-year
level of serv ice.
Project G: West Colfax Avenue Improvements
18-inch upgrades and replacement of an existing 36-inch pipe with a new 60-inch pipe is proposed in this
general area,
Page


FILE: GAcjis. ]]ionfct^lJr:nv'jrDiainac)ti ?U1 4,unrtivG^appsWapbook\2Q14 .SDMP_Mapb[iok.tnxd, Stf! D/2G14, chris_rrvartin
Key Map

/ j?

j o
L ^ %-S
4600-02
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
/ & V
& O
s/ ft? A W 13TH AVE OUTFALL : $6,204,046
B W 7TH AVE OUTLALL : $16,345,116
C W BAYAUD AVE OUTFALL : $23,568,746
D W ELLSWORTH AVE OUTFALL : $2,424,040
E W MULBERRY PL OUTFALL : $6,795,1 77
- F W 3RD AVE OUTFALL : $9,428,81 5
G W COLFAX AVE IMPROVEMENTS : $3,670,189
600 1,200
Feet
1 inch equals 1,200 feet
For Detailed Hydrology
See Technical Appendix
and Work Map
a Col lection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
-1 Proposed Detention
t Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
E^ll City and County Boundary
; Other Municipalities
I j Other Counties
Basin 0063-01
Central Platte Valley
Denver Storm Drainage Master Plan
Page 53


Denver Storm Drainage Master Plan
Basin 0064-01 (1st & Federal)
Existing System Description:
This collection system basin is tributary to Weir Gulch and the South Platte River by topography and pipe
network. In general, this basin is located south of Weir Gulch. The basin consists of 279 acres (0.44 square
miles) and includes residential in the upper reaches, and industrial/coinmcrcial in tire lower reaches Much of
the industrial land is within the current South Platte River floodplain.
Intercepted stormwater is discharged via 6 storm drainage outfalls into the South Platte River. The outfalls
include:
South Platte River
Yuma Street outfall is 21-inch for local drainage
5lh Avenue outfall is 42-inch with 172 tributary acres
6lh Avenue 42-inch outfall for 74 tributary acres
6lh Avenue 15-inch outfall for local drainage
7lh Avenue 36-inch outfall
S1*1 Avenue 24-inch outfall
The storm drain infrastructure consists of a random network of drains and laterals in the low reaches and
collectors in the residential reaches. The condition and capacity of the existing inlets is unknown at this time.
Blueprint Denver shows the Federal Boulevard subject to change along with some of the commercial and
industrial area adjacent to the South Platte River. The residential neighborhoods are shown as "Areas of
Stability" in Blueprint Denver
Drainage Deficiencies:
Significant portions of Basin 0064-01 arc within the South Platte River regulatory floodplain, including
subbasins 10, 20, and 32.
The areas in the South Platte River floodplain have capacity for the 2-year storm event, although this area
should have a 5-year level of serv ice by land use criteria.
Proposed Capital Improvements:
Proposed South Platte River channel improvements from W, 14lh Avenue to W, 8th Avenue will remove
much of the development in this basin from the regulatory floodplain, The lower reaches of Weir Gulch have
been improved to convey drainage during the 100-year event.
No major drainage complaints have been reported in these basins outside the regulatory floodplains due to
the relatively steep giadient toward the receiving drainage ways and lack of sumps or flat areas. This basin
generally meets Denver drainage criteria. The roads and drainage pipe convey the 2-year stonn event in
residential areas and 5-ycar stomi event in the commercial/industrial areas.
Most of the capital improvements proposed in Denver's 1989 Master Plan have been constructed. This area
has been improved by construction of diversion facilities to Weir Gulch implemented since the 1989 plan.
September 2014
A difficulty in constructing additional or replacement storm drain outfalls is the presence of the Metro
Sanitary Sewer along the west bank of the South Platte River. Otherwise, railroad tracks and the interstate
are located on the opposite bank of the South Platte, and there arc relatively few obstructions for new storm
pipe in this basin. Proposed projects include:
Project A: West 3rd Avenue Outfall
Stonn drain laterals are extended further into the basin to reduce street flooding. Stomi pipes smaller than
18-inch have been upgraded to 18-inch per current criteria.
Project B: West 8th Avenue Outfall
A new 3-foot x 6-foot box culvert outfall is proposed in 8th Avenue.
Project C: West 5th Avenue Outfall
A new 4-foot x 10-foot box culvert outfall is proposed in 5th Avenue to better sen e properties in the current
South Platte River floodplain. All 12-inch and 15-inch collector stomi drains do not meet current drainage
criteria and have been proposed for replacement with 18-inch pipes
Page 54


FIL£: G:\t|ii |ii Feet
1 inch equals 1,200 feel
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
Existing Basin
Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
n City and County Boundary
; Other Municipalities
l! ~ ~ j Other Counties
Basin 0064-01
1st & Federal
Denver Storm Drainage Master Plan
Page 55


Denver Storm Drainage Master Plan
Basin 0064-02 (Valverde)
Existing System Description:
This collection system basin drains to the South Platte River between 4111 Avenue on the north and Sanderson
Gulch on the south. The western boundary' of the basin is Morrison Road. The basin consists of 1,694 acres
(2.65 square miles). Much of the upper basin is comprised of residential neighborhoods, while the lower
portion is mostly commercial/industrial along the South Platte River. An existing detention basin is located
in West-Bar-Val-Wood Park located at W. Bayaud Avenue and S. Tejon Street. Improvements have been
constructed along Mississippi Avenue, which convey 3 10 cfs, in the minor storm, to Sanderson Gulch. The
improvements effectively remove almost all the Huston Lake area from this basin when considering the
minor storm events. In the major stonn, a 100-year runoff of 1,026 cfs is imported into this basin via
Mississippi Gulch located cast of S. Pecos and W. Mosicr Place. The 2013 Sanderson Gulch Major
Drainagenay Plan and Flood Hazard Area Delineation, by Matrix Design Group for the UDFCD,
evaluated a conveyance system to collect and convey the 100-year flows to Sanderson Gulch,
The storm drain infrastructure consists of a network of trank lines and laterals including fifteen outfalls.
Drainage from the basin is constrained by the South Platte River floodplain, which parallels the west side of
the river throughout the basin and has minimal topographic relief.
BluePriitt Denver shows Federal Boulevard. Alameda Avenue, and Morrison Road subject to change, along
with some of the commercial/industrial areas adjacent to the South Platte River,
Currently, a significant portion of the drainage basin (55% of the tributary area) outfalls through a 9-foot x
4 /i-foot box culvert at W 4th Avenue and Valiejo Street. Design point 1150 shows that 931 acres are
tributary to this one outfall
Drainage Deficiencies:
The existing pipe system that outfalls into the South Platte along Vallejo Street is undersized. Generally, the
lower portion of the system is located in the South Platte floodplain, which is relatively flat for drainage
purposes. The 9-foot x 4'A-foot box culvert is deficient due to the minimal 0.19% slope. The system can
convey the 2-ycar event in some areas but not in others. A 5-year design criteria should be set for this
industrial area.
The system in Dakota Avenue below Federal Boulevard will convey less than a one-year event. Stonn drains
below the commercial areas of Federal Boulevard should be sized for a 5-year event according to Denvers
stonn drainage cntcria. .
Localized drainage problems occur in the industrial areas along the river mostly due to relatively flat grades,
The areas north and south of Vanderbilt Park have been identified w ith drainage problems as well as
properties along S. Jason Street,
Proposed Capital Improvements:
This basin requires improvements primarily to the outfall since the lateral network is currently extensive in
this basin. The outfall should have 5-year capacity, whereas the lateral netw ork through the residential areas
should have a 2-year capacity7.
Project A: 18-Inch Upgrades
This project upsizes various pipes to the City's 18-inch minimum diameter pipe.
September 2014
Project B: S. Huron St Outfall
A 42-inch outfall is proposed along Huron Street to serve commercial properties along the South Platte River
in the southern portion of the basin.
Project C: W Alameda Avc. Outfall
A new dual system in W Alameda Avenue and W Byers Drive, from the South Platte River to S. Tejon
Street, is proposed to provide improved drainage in this basin. Upstream of Tejon. a 6-foot x 6-foot RCB and
84-inch RCP is proposed along Alameda Avenue to relieve the existing Vallejo Street System. The new7 pipe
will receive a portion of the flow from the Alameda/Alcott intersection, w'hilc the remainder of the flow will
be conveyed by the existing Vallejo Street outfall. Improvements are also proposed in Alcott Street between
Alameda and Virginia Avenues. A proposed 60-inch pipe along Virginia Avenue will relieve the existing
sy stem in Dakota Avenue by providing additional conveyance to serve subbasins 50, 60, 70, and 90. The
improvements extend west of Federal Boulevard and then along Federal Boulevard (or the alley west of
Federal) to provide stormwater interception for Federal Boulevard.
Project D: W. Arizona Ave, Outfall
A 54-inch outfall is proposed along Huron Street to serve commercial properties along the South Platte River
in the southern portion of the basin.
Project E: W Tennessee Avc. Outfall
A 42-inch outfall is proposed along Huron Street near Vanderbilt Park to reduce flooding along Jason Street.
Page 56


FILE: Gntjii ]]icjfcti'IJ:nvi:i[Jiaina!5a_2D14^irtivc\af)p!\Maf)b(>ok\3IJH_SDMP _Mapbook.mxd, 8/1D/2G14, chris.
Key Map

V
O
Barnum
Park Lake
Barnum
Park

'&r*


4900-01

WALAMEDAAVE


Lakewood

vv2
- ..A'-

Jj
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
Garfield
Lake
5100-01
Proposed Projects
* A- 18" UPGRADES : $1,029,604
B S HURON ST OUTFALL : $820,955
C W ALAMEDA AVE OUTFALL : $20,950,128
- D W ARIZONA AVE OUTFALL : $3,468,000
E W TENNESSEE AVE OUTFALL : $3,027,546
0 750 1,500
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,500 feel
Collection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
* Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
^ Significant Flooding Location
-1 Proposed Detention
t Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
E^l! City and County Boundary
; Other Municipalities
I j Other Counties
Basin 0064-02
Valverde
Denver Storm Drainage Master Plan
Page 57


Denver Storm Drainage Master Plan
Basin 0065-01 (Ruby Hill)
Existing System Description:
The Ruby Hill collection system basin is bounded between Federal Boulevard and the South Platte River, and
generally between Colorado Avenue and lliff Avenue. Ruby Hill Park is located along the South Platte River
in the northern portion of this basin, north of Jewell Avenue. A Power Plant is located in the southern
portion of the basin along the South Platte River. Approximately 20% of the basin is located within the
boundaries of Englewood (south of Evans, between Zuni and Pecos), and the remainder is in Denver
The Ruby Hill drainage basin is approximately 1.25 square miles in size and is fully developed with
residential and industrial properties in the upper reaches, and industrial properties in the lower reaches along
the banks of the South Platte River. The basin is relatively steep with Evans Avenue generally being the low
point (thalweg) of the drainage basin
The Evans system outfalls via a 72-inch pipe to the South Platte River. Other outfalls m the basin include a
36-inch pipe in Warren, a 48-inchx72-inch RCBC in lliff and other small local outfalls.
Drainage Deficiencies:
The existing drainage system has capacity to convey less than the 5-year stonn event within Evans Avenue
and Jewell Avenue, A small strip of Potential inundation areas occur within basins 300, 310 and 320. in a
commercial area, where the railroad embankment blocks the flow path to the South Platte River. The
Potential Inundation Area is immediately' adjacent to the railroad tracks and is too thin to show on the
adjoining map at this scale. The fiat topography along the South Platte River makes it difficult to adequately
drain the lower portion of this basin. Other problem areas include: *
* Basins 220, 230, 240, 250 and 260, which drain an industrial/residcntial area, should be sized for the
5-year event. The 5-year flow rate is 399 cfs. The existing 36-inch storm drain capacity' cannot
handle even the 2-year event of 221 cfs.
Proposed Capital Improvements:
Drainage improvements in this basin should be viewed primarily to achieve the minimum objectives for
residential and commercial areas (2-and 5-year system capacities) established for the City and County of
Denver. Although this basin has not been identified by Blueprint Denver as a significant area of change, re-
development of this area could provide an opportunity to construct the proposed facilities. Two existing
detention basins are located within the upper portion of the basin. The detention basins are located north of
W. Evans Ave, between S Vallejo Street and S. Tcjon Street. The two existing detention basins arc small and
are not modeled in the hydrologic analysis. No improvements to these facilities are proposed.
The proposed storm drainage improvements are summarized below;
Project A: 18-inch Upgrades
This project includes upsizing an existing 15-inch storm drain lateral located within the alley between
Kaiamath and Jason Street to an 18-inch storm drain.
September 2014
Project B: S. Lipan St. Outfall
Construct a new outfall to the South Platte River in S, Lipan Street, This new' system will be between Jewell
Avenue and Evans Avenue and extend west in Evans Avenue to Navajo Street. This new outfall will convey
the 5-year storm event from Proposed Projects C, D1 and D2 to the South Platte River.
Project C; S. Pecos and W lliff Improvements
Construct a new- 5-year storm drain to collect and convey storm flows along the west side of the Burlington
Northern and Santa Fe Railroad and around the commercial site along South Pecos Street to Proposed Project
B in Evans Avenue.
Project Dl: W. Evans Avenue Improvements
Upsize the existing storm drain in Evans Avenue between S, Navajo Street and S, Tcjon Street to convey the
flows from Proposed Project D2 to Proposed Project B.
Proiect D-2: W Evans Ave. Extension
Upsize the existing stonn drain facility' to a 5-year capacity within Evans Avenue from the existing detention
basin at W. Pacific Place to S. Clay Street. Upsize laterals in S. Clay Street and S. Zuni Street between W,
Evans Avenue and W. Warren Avenue. Upsize the culvert under W, Asbury Avenue between the two small
detention basins.
Page 58


Fll_£: G:\cjii imijccti'iIJijnvorDinimgi: ?01 llactivc\appiW:ipb(>[]lriOD65-01 .mxd, 8/19^2014, Dbris_martm
Basin 0065-01
Ruby Hill
Denver Storm Drainage Master Plan
Page 59


Denver Storm Drainage Master Plan
Basin 0065-02 (Dartmouth)
Existing System Description:
The Dartmouth Collection System Basin borders West Harvard Gulch Basm directly to the south. Tire
Dartmouth basin is bounded between Federal Boulevard and the South Platte River, and generally between
Amherst and Hampden Avenues. Most of tire basin is located within the boundaries of Englew ood, and only
approximately 30% of the basin is in Denver., Denver's portion includes the upper steep reaches north ofW.
Dartmouth Avenue between Federal Boulevard and Zuni Street, and an industrial complex located along tire
banks of tire South Platte River north of Dartmouth Avenue.
The Dartmouth collection system basin is approximately 0.76 square miles in size and is fully developed with
residential properties in the upper reaches, and industrial properties in the lower reaches along the banks of
the South Platte River. Land use mix in the basin is about 1/3 residential and 2/3 commercial and industrial.
The basin is relatively steep with Dartmouth Avenue generally being the low point (thalweg) of the drainage
basin.
No outfall pipes in this basin arc shown in the Denver GIS database since the outfall for this basin is in
Englewood
Drainage Deficiencies:
Currently this basin drains east to Englewood's storm drainage system which drains into the South Platte
River. The 5-year flow rate is 424 cfs. The existing Englewood system ranges in size from a 42-inch pipe to
73-inchx55-inch elliptical pipe. There is not sufficient data to determine if the existing Englewood pipe is
sufficient to convey the 5-year storm event. No future improvements will be proposed outside of the City
and County' of Denver,
Proposed Capital Improvements:
Project A: S. Bryant Street Improvement
Only a small improvement is recommended along South Bryant Street from Dartmouth Avenue to and west
in Cornell Avenue. A 24-inch. 2-year capacity' storm drain is proposed.
September 2014
Page 60


F1L£: G:\cj it picijcctiiUJuiiver Dramarja_2D14'i:irtivi:\iif)pt,iMnf)book\?OH_SDMP_MapboDk.mxd, D/2014j chris. martin
Feet
1 inch equals 1,200 feel
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
Existing Basin
Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
E^l! City and County Boundary
; Other Municipalities
^ Other Counties
Basin 0065-02
Dartmouth
Denver Storm Drainage Master Plan
Page 61


Denver Storm Drainage Master Plan
Basin 0067-01 (College View)
Existing System Description:
The College View Collection System Basin has a total drainage area of approximately 1.29 square miles.
This basin flows east through Denver and Littleton to its confluence with the South Platte River The lower
portion is outside die City and County of Denver and was not studied. The basin is currently fully developed
with the exception of a few scattered vacant lots including residential, commercial and industrial areas.
Drainage Deficiencies:
The entire storm drain system w ithin the College View Basin is adequate!) sized for the 2-ycar storm event
However, the storm drain system should have 5-year capacity due to the commercial areas through the
neighborhood. Much of the residential area along West Quincy Avenue does not have any storm drain
system and would benefit from a new lateral.
Proposed Capital Improvements:
Two major storm drain projects have been proposed in this basin to increase the level of service from a 2-
year capacity to a 5-year capacity.
Protect A: S. Quitman Street Improvements
A new 18-inch to 24-inch stonn drain from W. Quinn Place to W. Stanford Avenue and S. Quitman Street is
proposed.
Project B: West Union Avenue Improvements
The existing storm drain system along West Union Avenue docs not meet the minimum required
performance objectives for a 5-year storm drain. Upsizing the existing stonn drain system to a 42-inch pipe
will satisfy1 this requirement.
Difficulties in constructing a new outfall system for this basin would include coordination w ith downstream
municipalities at the two outfall locations. Lowell Boulevard and Federal Boulevard. Agreements should be
in place before any designs are considered.
September 2014
Page 62


FILE:G:tyisj]rojectii,i.lJunvar[)iziinar|ti 2014iactivG^app5Wapbook\30H_SDMP_Mapbook.mxd, 8^13/201chris_rnartin
Proposed Projects
A -S QUITMAN ST IMPROVEMENTS : $1,612,118
B W UNION AVE IMPROVEMENTS : $1,829,587
0 600 1,200
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,200 feet
Collection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe -1 Proposed Detention I Existing Transit Line
Designed Storm Improvement t Basin Existing Basin _~|| City and County Boundary
Existing Surface Flow i 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line l! r Other Counties
Basin 0067-01
College View
Denver Storm Drainage Master Plan
Page 63


Denver Storm Drainage Master Plan
Basin 0067-02 (West Belleview)
Existing System Description:
The West Belleview Collection System Basin has a total drainage area of approximately 4.21 square miles.
This basin flows east through Denver and Littleton to its confluence with the South Platte River. The lower
portion of this basin is outside the City and County of Denver and was not studied. The basin is currently
fully developed with the exception of a few scattered vacant iots including residential, commercial and
industrial areas.
Drainage Deficiencies:
The existing development in these basins is relatively new Grant Ranch within Basin 0067-02 has been fully
developed and the storm drain appears to be adequate in this area. The drainage basins to the north along W.
Belleview Avenue and within Basin 0067-02 have no existing storm drain in Denvers GIS database.
Proposed Capital Improvements:
Project A: W. Grand Avenue Improvements
The existing residential neighborhood along W, Grand Avenue currently does not have any storm drains. A
2-ycar capacity storm drain system is proposed along W. Grand Avenue and will connect to Englewood's
storm drain system at W, Grand Avenue and S, Meade Street
September 2014
Page 64


FILE: G:\cjis j]iojtfct*,ilJi:nvi:!rDiBiriaga_2D14'taclrva\appsWapbook\2014_SDMP .MapboDk.mxd, 8/1D/2G14, c6ris_martin
Feet
1 inch equals 1,500 feel
Boundary
Thalweg
Proposed Pipe
Disconnect
Legend
*- Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
Existing Basin
Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
ET1 City and County Boundary
2 1 Other Municipalities
Other Counties
Basin 0067-02
West Belleview
Denver Storm Drainage Master Plan
Page 65


Denver Storm Drainage Master Plan
September 2014
Basin 0067-03 (Marston Lake)
Existing System Description:
The Marston Lake Collection System Basin has a total drainage area of approximately 1.06 square miles.
This basin is within Denver and has no outlet. A 12-foot high berm surrounds the reservoir, which is owned
and operated by Denver Water for potable water storage, and keeps stormwater from entering or leaving. A
small portion of Marston Reservoir does include a small residential area with no outlet.
Drainage Deficiencies:
No drainage deficiencies are identified at this time,
Proposed Capital Improvements:
No improvements are proposed.
Page 66


F1L£: G:\tjit .piojcctiUJunverDiainatje 2014iactiYfl^appsWapbook\2014_SDMP_Mapbook.tnxd, Stfl D/201 A, chris_martin
Key Map

/ Jefferson County
i. jn i 1/ V
ferry's J
Vvv ^ Lake
C /
I O' * 1 Utile Lake

1,200
Feet
1 inch equals 1,200 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
| Topographic Basin
Boundary
Thalweg
X
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
-1 Proposed Detention
' Basin
Existing Basin
|----1 Potential Inundation
'---- Area
I---- Planned Transit Line
I Existing Transit Line
E^l! City and County Boundary
; Other Municipalities
0 Other Counties
Basin 0067-03
Marston Lake
Denver Storm Drainage Master Plan
Page 67


Denver Storm Drainage Master Plan
Basin 3501-01 (West Fork Second Creek)
Existing System Description:
The West Fork of Second Creek is located along the southern boundary of DIA within the City and County of
Denver and drains about 3.45 square miles of area to the main branch of Second Creek. West Fork Second
Creek flows across Pena Boulevard at the 90Cl bend and continues in a northwesterly direction, eventually
outfalling to the South Platte River. There is limited existing development within the West Fork Second
Creek Collection System Basin. The land is mainly agricultural, with dryland farming and pasture in the
upper reaches.
The High Line Canal terminates at the West Fork. The sustained unused flow in the High Line Canal has
historically been wasted to the West Fork downstream of 64th Avenue, and the flows have eroded the channel
on the West Fork At Tower Road the West Fork channel is about i 5 feet deep with vertical and very' steep,
unstable banks. The confluence of Second Creek and the West Fork of Second Creek is a w ide, relatively flat
area supporting a stand of cottonwood trees. Some wetland areas arc present in the upper reaches of the West
Fork. but. as the channel has eroded, the channel banks have become incised and support only a narrow band
of wetland or riparian vegetation. The floodplain is contained within die channel except at road crossings,
where overtopping may occur The banks arc unstable and some lateral channel migration may occur during
large flow:s.
Identified Drainage Problems/Deficiencies:
West Fork Second Creek is largely undeveloped, and drainage is primarily via open channels and swales.
There are few storm drain pipe systems within the basin. Since there is little development, the system
currently functions without ponding or drainage problems, except for channel erosion which will be
exacerbated by further development,
Proposed Capital Improvements:
The drainage basin is currently mostly undeveloped with a low imperviousness. The Second Creek and
Direct Flow Area 0053 Outfall Systems Planning Study, Preliminary Design completed by Kiowa
Engineering for the Urban Drainage & Flood Control District in May 1990, assumes the upper reaches of the
basin will be developed with an average 70% imperviousness. The OSP calls for channel stabilization
measures by constructing a series of drop structures along the channel. These improvements w ill be
constructed commensurate with development.
The Pena Boulevard Transportation Corridor includes land extending 250 feet from centerline for a future
light rail/ commuter rail line. Therefore, existing and proposed detention basins are not immediately adjacent
to Pena Boulevard.
Two regional detention facilities are currently proposed in the basin, along with multiple, smaller detention
facilities serving future developments.
Project A: Highooint Open Channel
The 101.9 acre-foot High point Pond7 is located east of Tower Road and north of 72nJ Avenue and was
master planned to reduce flows to historic conditions in the West Fork Second Creek. Open channel
improvements will be required to serve as conveyance from future development areas into the West Fork of
Second Creek. These improvements will be required as development occurs to adequately convey flows to
the culvert upstream of 72nd Avenue on the West Fork of Second Creek.
September 2014
Project C: Second Creek Grade Control
Channel stabilization is required on about 18.000 lineal feet of the West Fork Second Creek. The channel
will be graded from steep unstable banks to a channel with sloped overbanks and with a top width of about
40 to 45 feet. An estimated 35 drop structures arc also proposed to stabilize the channel by shallowing the
existing grade.
Page 68


0 750 1,500
Feet
1 inch equals 1,500 feet
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
-1 Proposed Detention
Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
fTDI City and County Boundary
2 1 Other Municipalities
Other Counties
Basin 3501-01
West Fork Second Creek
Denver Storm Drainage Master Plan
Page 69


Denver Storm Drainage Master Plan
Basin 3700-01 (First Creek & Pena Corridor)
Existing Basin Description:
The First Creek Collection System Drainage Basin is located south of DIA and crosses Peha Boulevard just
north of 56th Avenue, West of Pena Boulevard. First Creek flows through the southeastern portion of the
Rocky Mountain Arsenal. First Creek enters Rocky Mountain Arsenal with an incised, low flow channel and
wide floodplain.
Basin 3700-01 is entirely within the City and County of Denver and has been defined as the area within the
wide Pena Boulevard corridor, owned by DIA. that will not experience further development, The east
corridor of the light rail/commutcr train was under construction cast of Pena Boulevard at tire time this report
was published. A portion of die First Creek Basin extends upstream to the outlet of the regional Green
Valley Ranch Golf Course detention pond This basin is 2.23 square miles and will include future
development, General imperviousness is 8% along Pena Boulevard, and about 63% further upstream on First
Creek
Identified Drainage Problems/Deficiencies:
The Pena Boulevard corridor is a wide area for Peha Boulevard and the new light rail/commuter train and
contains sites planned for regional detention before outfaJling into the Rocky Mountain Arsenal. The basin is
actively being developed in accordance with current drainage criteria, which is the 100-year storm event,
Therefore, no existing deficiencies have been identified.
Proposed Capital Improvements:
Urban Drainage & Flood Control District prepared drainage master plans prior to development of the basin
and has required incorporation of regional water quality' and detention into land planning, All development
in the First Creek Drainage Basin must detain and treat water quality on-site or in regional basins since runoff
wi 11 flow into the Rocky Mountain Arsenal. The Arsenal has strict agreements for the quantity and quality of
stormwater runoff into the federal property The First Creek (Upstream of Buckley Road) Major
Drainageway Plan: Conceptual Design Report, prepared by Moser & Associates for the UDFCD and
published in August 2010. recommended channel improvements and floodplain preservation within Basin
3700-01.
Two regional detention facilities, the Blue Grama Draw detention pond and die Dogwood Gulch detention
pond, were previously planned widiin diis basin, within the Pena Boulevard conidor. The two basins have
been combined into one basin, the Blue Grama Draw detention pond, as part of the RTD FasTracks East
Corridor project, and further analysis is underway by the UDFCD to model these revisions, and amend
UDFCD IGA No. 99-03.11 if needed.
Master Plan Agreements:
Many' documents and agreements that specify- 100-ycar discharges and storage volumes have been compiled
for the First Creek Drainage Basin, Therefore, nothing in this Master Plan shall take precedence over those
agreements or specified discharges, This study was completed for the purposes of analyzing initial storm
flows for die 2- and 3-year events. Agreement 99-03.11, dated January 22. 2001, states the following for the
Blue Grama Draw pond (#305):
September 2014
Master Plan Design Parameters
ID No. Peak Inflow (cfs) Peak Outflow (cfs> Volume (AF> Jurisdiction
303 2027 1929 269 Denver
Page 70


F1L£: G:\tjit j]ioj<*ctillJi:nvorDiainagfl_2D14taclrvfl\appsWBpbook\2014 _SDMP_Mapbook_No.TDpo.mxd, EW19^2D14, chris
Key Map

/ ID

/Y\
/
-i

n
Aurora
Adorns County
n
Pond C j f

Higbpoint
Detention Pond
701.9 AF
3501-01
3700-02
^ X
y
G I//? GC Pondakp
Himalaya Pond,
akciPond 808
Pond
826
Pond 800
i
3700-03
I r,_, .XL
(fV --------

*A < -~
k v & /. dQSrz '
- * / ib-i
j" t-Iwtob
V "4*
+ 1 .. -_-rv
N TOWER RD
\
[SUCKLE r.kuj^jjj^LE vapj


&K.- \


Adams County

Stiver^.
Detention Ponder
HIr
0 700 1,400
For Detailed Hydrology
See Technical Appendix
and Work Map
| Collection System
I Boundary
Feet
1 inch equals 1,400 feel
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
1 Existing Storm Pipe Proposed Detention t Basin
Designed Storm Improvement Existing Basin
*- Existing Surface Flow | 1 Potential Inundation ' Area
Significant Flooding Location 1 Planned Transit Line
I Existing Transit Line
E^l! City and County Boundary
; Other Municipalities
l
L Other Counties
Basin 3700-01
First Creek & Pena Corridor
Denver Storm Drainage Master Plan
Page 71


Denver Storm Drainage Master Plan
Basin 3700-02 (First Creek Green Valley Ranch)
Existing Basin Description:
Collection System Basin 3700-02 is primarily within the City and County' of Denver, but includes some area
within Adams County. The basin includes area within Denver that is tributary to the regional Green Valley
Ranch Golf Course detention Pond, also known as the Himalaya Pond and "Pond 808. This basin is being
developed by Green Valley Ranch and includes 2.12 square miles. First Creek runs through this basin, and
bisects Green Valley Ranch, which consists of medium density, single-family residences. General
imperviousness was master planned as 70% for the 2005 Storm Drainage Master Plan and in the 2009
Storm Drainage Master Plan it was lowered based on actual imperviousness. The new values have been
earned forward to this Master Plan update. Sec First Creek (Upstream of Buckley Road) Major
Drainageway Plan: Conceptual Design Report, prepared by Moser & Associates for the UDFCD and
published in August 2010, for flows upstream of E. 38th Avenue and N. Picadilly Road (DP 076).
Identified Drainage Problems/Defiriencies:
The basin is mostly developed and was developed in accordance with current drainage criteria, which is the
100-ycar storm event. Therefore, no existing deficiencies have been identified.
Proposed Capital Improvements:
Urban Drainage & Flood Control District prepared drainage master plans prior to development of the basin
and has required incorporation of regional water quality and detention into land planning All development
in the First Creek Drainage Basin must detain and treat water quality on-site or in regional detention basins
since runoff will flow' into the Rocky Mountain Arsenal. The Arsenal has strict agreements for the quantity
and quality of stormwater runoff into the federal property. The First Creek (Upstream of Buckley Road)
Major Drain agency Plan: Conceptual Design Report recommended floodplain preservation within Basin
3700-02.
There are no additional planned improvements for the basin, beyond the capital construction required for the
Green Valley Ranch development.
Master Plan Agreements:
Many documents and agreements have been compiled for the First Creek Drainage Basin, These documents
specify- 100-year discharges and storage volumes. Therefore, nothing in this Master Plan shall take
precedence over those agreements or specified discharges. This study was completed for the purposes of
analyzing initial storm flows for the 2- and 5-yrear events. Agreement 99-03.11, dated January 22. 2001.
states the following for the "Green Valley Ranch Golf Course Pond or the "Himalaya Pond (#808):
Master Plan Design Parameters
ID No. Peak Inflow (cfs) Peak Outflow (cfs) Volume (AF> Jurisdiction
808 4857 4306 263 Denver
However, the pond was constructed with 369 acre-feet of storage, rather than the 263 acre-feet per the
agreement.
September 2014
Page 72


FILE: Gi\cjis jirojffctiAIJcinvrjrDiainacjie .2014'iac,tivt3^appsWapbook\2014 _SDMP _Mapbook_No_TapD.mxd, fl.M9f2D14, chns_mar1in
NOTE: See First Creek (Upstream of Buckley Road)
Major Drainageway Plan: Conceptual Design Report,
prepared by Moser & Associates for the UDFCD and
published in August 2010, for flows upstream of E.
38th Avenue and N. Picadilly Road {DP 076).
Feet
1 inch equals 1,400 feet
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
Existing Basin
Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
E^l! City and County Boundary
1 Other Municipalities
Other Counties
Basin 3700-02
Green Valley Ranch
Denver Storm Drainage Master Plan
Page 73


Denver Storm Drainage Master Plan
Basin 3700-03 (First Creek Dogwood & Blue Grama Tribs.)
Existing Basin Description:
Collection System Basin 3700-03 is located within the City and County of Denver and Adams County. This
basin has been defined as the area draining to the Dogwood Gulch Tributary- and the Blue Grama Draw
Tributary. This basin is 2.61 square miles and is actively being developed. The subdivisions of "Denver
International Business Celiter, High Point/ and Single Tree at DIA': are within this drainage basin
General i in perviousness, at full development will be around 65%,
Identified Drainage Problems/Deficiencies:
The basin is actively being developed in accordance with current drainage criteria, which is the 100-ycar
storm event. Therefore, no existing deficiencies have been identified.
Proposed Capital Improvements:
Urban Drainage & Flood Control District prepared drainage master plans prior to development of the basin
and has required incorporation of regional water quality and detention into land planning. All development
in the First Creek Drainage Basin must detain and beat water quality on-site or in regional detention basins
since runoff will flow into the Rocky Mountain Arsenal. The Arsenal has strict agreements for the quantity
and quality of stormwater runoff into the federal property. The First Creek (Upstream of Buckley Road)
Major Drain ageway Plan: Conceptual Design Report, prepared by Moser & Associates for the UDFCD and
published in August 2010, contained no recommendations in this basin.
Multiple detention basins are planned throughout the basin in conjunction with development, both on
Dogwood Gulch and Blue Grama Draw
Project A; Dogwood Gulch Pond 812
This 13 acre-foot detention basin will be constructed as development occurs. It will be located immediately'
to the east of the Pena Boulevard corridor, between 66th and 68th Avenues. This detention basin will serve to
regulate increased flows from the development back into Dogwood Gulch as it enters the Pena corridor,
Project E: Blue Grama Draw Pond 802
This 33 acre-foot detention basin will be constructed as development occurs. It will be located immediately
to the cast of Tower Road, between 60th and 64th Avenues. This detention basin will serve to regulate
increased flows from the development back into Blue Grama Draw- before crossing Tower Road
Project G: Blue Grama Draw Pond 816
This 40 acre-foot detention basin, in Aurora, will be constructed as development occurs. It will be located
immediately to the north of 60lh Avenue and to the west of the High Line Canal in Adams County. This
detention basin will serve to regulate increased flows from the development back into Blue Grama Draw.
Project H: Blue Grama Draw Pond 826
This 23 acre-foot detention basin is partially constructed. It will be located immediately to the south of 60th
Avenue, and w ill eventually be on both sides of Argonne Street. This detention basin will serve to regulate
increased flows from the development back into Blue Grama Draw'. Currently only a portion of this
detention basin at the east side of Argonne Street is constructed, as only a portion of the tributary area is
developed, The other portion of this detention basin at the west side of Argonne Street will be constructed to
offer an additional 11 acre-foot sendee levels for the future development.
September 2014
Open Channel Improvements
Generally, this basin requires a series of open channel improvements associated with each detention basin to
serve as conveyance channels for both Dogwood Gulch and Blue Grama Draw'. These open channel
improvements, and associated culvert crossings, will be required as development occurs.
Master Plan Agreements:
Many- documents and agreements that specify- 100-year discharges and storage volumes have been compiled
for the First Creek Drainage Basin. Therefore, nothing in this Master Plan shall take precedence over those
agreements or specified discharges. This study was completed for the purposes of analyzing initial storm
flows for the 2- and 5-year events Agreement 99-03.1 L dated January 2, 2001, states the follow ing:
Master Plan Design Parameters
ID No. Peak Inflow (cfs) Peak Outflow (cfs) Volume (AF) Jurisdiction
800 419 120 11 Denver
801 1226 655 37 Aurora
802 982 920 33 Denver
8)2 444 216 13 Denver
816 864 438 40 Aurora
826 589 180 23 Denver
Page 74


F1L£: G:\cjis piojttctiiMJcnvQrDiainajjtt ?014'%irtivr:\appi\MapboDk\30H_SDMP .Mapbook_Mo.TDpo.mxd, EW1SN2D14, chris_mar1in
2 - Proposed Projects
E POND 802 DETENTION : $9,1 38,763
Feet
1 inch equals 1,500 feet
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
- i Proposed Detention
t Basin
Existing Basin
I-----1 Potential Inundation
I Existing Transit Line
n City and County Boundary
; Other Municipalities
Planned Transit Line ___ n Other Counties
Basin 3700-03
Dogwood & Blue Grama Tribs.
Denver Storm Drainage Master Plan
Page 75


Denver Storm Drainage Master Plan
Basin 3702-01 (First Creek Tributary T)
Existing Basin Description:
Collection System Basin 3702-01 is defined as the portion of Denver draining to the channel known as
Tributary "T\ which enters Denver near N. Picadilly Road and E. 4Xtb Place. This basin is also extends into
Adams County. The basin area is 0.9! square miles and will include future development and the Green
Valiev Ranch Golf Course. Overall master planned imperviousness is about 70%.
This tributary extends farther upstream beyond the limits of this basin into Adams County. The upper
reaches of Tributary T' Basin have been master planned for development under the direction of Urban
Drainage & Flood Control District by Wright Water Engineers in 1990, Turner, Collie & Braden in 2000,
Muller Engineering in 2003, and Moser & Associates Engineering in 2010. In addition, development
engineers have also studied the basin and include Martin & Maitin in I99S, Vestal Engineering in 2004, and
Stantcc in 2005. Other development engineers have also completed studies of the basin, See First Creek
(Upstream of Buckley Road) Major Drainageway Plan: Conceptual Design Report, prepared by Moser &
Associates for the UDFCD and published in August 2010, for flows upstream of Green Valley Ranch Blvd.
and N. Picadilly Road (DP 070).
Identified Drainage Problems/Deficiencies:
The basin is actively being developed in accordance with current drainage criteria, which is the 100-vear
storm event. Therefore, no existing 2- and 5-year deficiencies have been identified.
Proposed Capital Improvements:
Urban Drainage & Flood Control District prepared drainage master plans prior to development of the basin
and has required incorporation of regional water quality' and detention into land planning. All development
in the First Creek Drainage Basin must detain and treat water quality on-site or in regional detention basins
since runoff will flow into the Rocky Mountain Arsenal. The Arsenal has strict agreements for the quantity
and quality of stormwater runoff into the federal property. The First Creek (Upstream of Buckley Road)
Major Drainagen'ay Plan: Conceptual Design Report recommended floodplain preservation within Basin
3702-01.
There are no further planned improvements for the basin, beyond the capital construction required for the
Green Valley Ranch development.
Master Plan Agreements:
Many documents and agreements that specify' 100-year discharges and storage volumes have been compiled
for the First Creek Drainage Basin. Therefore, nothing in this Master Plan shall take precedence over those
agreements or specified discharges. This study was completed for the purposes of analyzing initial storm
flows for the 2- and 5-year events.
September 2014
Page 76


FILE: G:\gie_prejts'tDsnvsrDr,ainaga_20l4teetrva,|appsWapBook\20l4_SDMP_MapBook_No_Topo.m:x:d, flyiS/2014, ehrie_martin
NOTE; See First Creek (Upstream of Buckley Road)
Major Drainageway Plan: Conceptual Design Report,
prepared by Moser & Associates for the UDFCD and
published in August 2010, for flows upstream of Green
Valley Ranch Blvd. and N. Picadilly Road (DP 070).
600 1,200
Feet
1 inch equals 1,200 feel
For Detailed Hydrology
See Technical Appendix
and Work Map
| Collection System
I Boundary
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Existing Storm Pipe ,- Proposed Detention I Existing Transit Line
Designed Storm Improvement ' Basin Existing Basin [)J" _~|j City and County Boundary
Existing Surface Flow | 1 Potential Inundation I 1 Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line l! r Other Counties
Basin 3702-01
Tributary T
Denver Storm Drainage Master Plan
Page 77


Denver Storm Drainage Master Plan
Basin 3900-01 (Irondale Gulch Stapleton)
Existing Basin Description:
This collection system basin is located within Section 10 of the former airport, Stapleton Redevelopment site
(City and County of Denver) and partially within the Rocky Mountain Arsenal (Adams County), The basin
is a tributary to Irondale Gulch, which is tributary to the South Platte River. The basin consists of about 140
acres and is currently undeveloped, except for former runways and storage of crushed concrete. The basin
was similarly defined in the 1989 Denver Drainage Master Plan, but included more land within the Arsenal
north of Irondale Gulch in Adams County, Topography within the basin is characterized by generally flat
terrain. Discharge from this basin flows to the north (downstream) into the Rocky Mountain Arsenal.
Irondale Gulch docs not have an improved channel to the South Platte River, and therefore runoff in the basin
is controlled by detention and retention basins There are also limitations to discharges into the Arsenal, The
redevelopment of Stapleton will include detention to control runoff.
Identified Drainage Problems/Deficiencies:
In general, there arc currently no trunk storm pipes within this basin. Depressions between die runways have
captured stormwater runoff and directed it via overland flow into Irondale Gulch,
Discharges from this basin into the Rocky Mountain Arsenal must be limited to histone conditions. The
previous study for this basin was the 1995 Stapleton Area Outfall Systems Plan (OSP) by Urban Drainage &
Flood Control District and McLaughlin Water Engineers, which set die discharge for existing and developed
conditions as shown.
Potential Improvements:
The Stapleton Development Master Plan includes a detention basin, which will be constructed in this basin at
the Denver border commensurate widi development, to limit discharges to historic conditions. Proposed
detention basin (Pond #21) is at die border of die Rocky Mountain Arsenal. This detention basin is estimated
to be about 10 acre-feet and will release into the Arsenal at die defined historic rates.
September 2014
Page 78


FILE: G:\t|is. iminfct^UeiiveiDinimtji: ?01 Vuictiv stepps Wapbook\2014_SDMP_Mapbnok_No_TnpD.mxd, EtyiUftDH, chrisjnarlin
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
Ladora
Lake
Derby
Lake
Southgate
Pond

3901-01 3900-02

i
a
i
0 600 1,200
Feet
1 inch equals 1,200 feel
For Detailed Hydrology
See Technical Appendix
and Work Map___________
Collection System
Boundary
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
- i Proposed Detention
t Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
rj City and County Boundary
; Other Municipalities
Other Counties
Basin 3900-01
Stapleton
Denver Storm Drainage Master Plan
Page 79


Denver Storm Drainage Master Plan
Basin 3900-02 (Irondale Gulch East Montbello)
Existing Basin Description:
This collection system basin is located fully within the Montbello neighborhood in the City and County of
Denver. The boundaries of this basin are 56th Avenue to the north. Chambers Road to the east, the northern
boundary of Basin 3901-01 to the south, and Peoria Street to the west. The basin consists of about 1.221
acres and is fully developed with residential neighborhoods. Low flows are conveyed in open channels and
pipe systems, while higher flows are convey ed overland through the streets. Topography is characterized by
generally flat terrain and there arc no large, regional detention facilities internally within the basin.
Discharge from the basin flows generally northerly through a series of concrete channels and pipes until
crossing under 56^ Avenue. A regional detention facility-, known as the "'Havana Pond' or "Southgate Pond'
is located on the Rocky Mountain Arsenal property north of 56lh Avenue Beyond that point, flows also enter
Ladora Lake and Lake Mary on the Arsenal property. Very' little flow is discharged to Irondale Gulch from
Lake Mary, except in large events.
This basin currently has 7 storm pipes that cross north under 56th Avenue. East of Peona Street is a storm
pipe running along Revere Street discharging flows under 56lh Avenue at design point 40. There are other
minor storm pipes under 56lh Avenue to each side of design point 40, but all flow s from the contributing area
within Basin 3900-02 were modeled to enter the RM A at design point 40. Further east of design point 40 is
design point 51. Flow is collected in a storm pipe system and discharged to an open channel along Uvalda
Street. Those flows are conveyed under 56th Avenue to the RMA. Other pipe systems discharge at design
points 48 and 49 into a ditch on the north side of 56lh Avenue. Basin 3900-04 flows into Basin 3900-02.
Upstream runoff, attenuated in the Chambers I Pond, flows into Basin 3900-02 at Chambers Rd and 48Ih
Avenue.
Identified Drainage Problems/Deficiencies:
This drainage basin is essentially fully developed with single-family residential properties. By Denver
criteria, the initial storm is a 2-year event for residential areas. The Irondale Gulch Stormwater Outfall
Systems Plan and Preliminary Design Report, dated May 1990 by Wright Water Engineers states, "The
Montbello area currently suffers from a lack of adequate capacity for major floods. The existing channels
have the capacity of around the 5- to 10-year flood.
The concrete trapezoidal channels and storm pipe systems that are currently in place apparently had a design
goal to convey the 10-year flow. However, due to changes that occurred during construction, some systems
are oversized, while others are undersized. Specifically, the concrete trapezoidal channel in 53ld Avenue was
likely planned to extend further east past Chambers. However, as-built conditions direct all stormwater cast
of Chambers easterly into Parkfield Lake,
Potential Improvements:
The 1990 study was completed to upgrade all facilities within the Montbello Area to 100-year capacity. The
greatest constraint was the undersized road crossings over the open channels. By reconstructing these
crossings, major conveyance facilities would be able to convey larger storm events. In areas where
additional capacity is required, the 1990 study proposed replacing the sloping walls with vertical concrete
walls to establish a rectangular concrete channel within the right-of-way of the existing channel. A site visit
confirmed that four Irondale Gulch culverts along Uvalda Street have been upgraded in size; however, the
remaining 7 culverts along Irondale Gulch have not been constructed. A recommendation was also made in
the 1990 study to change the bottoms of the existing concrete channels to wetlands for water quality benefits.
However, these changes have not been implemented. There has been greater emphasis on detention to reduce
September 2014
flows to the capacity' of existing systems, As upstream development has occurred, detention has been
required to keep the flood peaks from increasing above existing levels.
The Irondale Gulch Outfall Systems Plan Conceptual Design Report was completed in 2011. Hydrology
was updated for die entire Irondale Gulch watershed, including Basin 3900-02. The upper limit of proposed
improvements in the OSP was the Denver/Adams County boundary and, therefore, no improvements were
evaluated or shown in Denver.
Project A: E 53rd Avc. bnprovements and Project B: E Maxwell PI. Improvements
The 1990 Urban Drainage & Flood Control District study focused on major drainageway conveyance.
Improvements needed beyond those evaluated in the previous study are additional stonn drain laterals. These
laterals arc suggested to reduce flows in streets during minor-events and reduce ponding and cross street
flow.
Master Plan Agreements:
Many documents and agreements that specify- 100-y-ear discharges and storage volumes have been compiled
for the Irondale Gulch Drainage Basin. Therefore, nothing in this Master Plan shall take precedence over
those agreements or specified discharges. This study was completed for the purposes of analyzing initial
storm flows for the 2- and 5-year events. Refer to Urban Drainage &. Flood Contra! District master plans for
100-ycar d i schargcs.
Page 80


FILE: GAt|ii ]]ioject^lJi:nv'jr[)i n
O 600 1,200
Feet
1 inch equals 1,200 feet
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe -1 Proposed Detention 1 Existing Transit Line
Designed Storm Improvement t Basin Existing Basin _~|j City and County Boundary
Existing Surface Flow | 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location 1 Planned Transit Line H ~ ~ 1 Other Counties
Basin 3900-02
East Montbello
Denver Storm Drainage Master Plan
Page 81


Denver Storm Drainage Master Plan
Basin 3900-03 (Irondale Gulch Parkfield)
Existing Basin Description:
This collection system basin contains the Tower Outfall Lateral and the Higliline Lateral and is located
through three neighborhoods in the City' and County of Denver; Parkfield. Denver Connection, and Green
Valley Ranch. The boundaries of this basin arc 56th Avenue and die southern boundary of the First Creek
Basin to the north, the middle of the Green Valley Ranch neighborhood to the east, the northern boundary of
Basin 3900-04 and 38tb Avenue to the south, and Chambers Road to the west. The basin consists of about
1,873 acres and is partially' developed with residential neighborhoods, with plans for commercial and
residential developments in the near future. Low flows are conveyed through storm pipes and open channels
to regional detention facilities including Parkfield Lake, Parkfield II Lake, High line Pond, Silverado I Pond
and two Green Valley Ranch detention facilities. High flows are conveyed through some of the stonn pipe
system and overland through the streets to the detention areas. Topography is characterized bv generally flat
terrain with runoff discharge flowing generally to the northwest toward Parkfield II Lake in the northwest
comer of 56lh and Chambers.
Identified Drainage Problems/Deficiencies:
The Highline and Silverado I Ponds required modification due to impacts of the new RTD FasTracks East
Corridor light rail/commliter train. The Highline Pond slightly exceeds, by 0.1 acre, the allowable surface
acreage according to an internal memo between Denver, Aurora, and Denver International Airport (D1A)
which sets the maximum pond acreage to 7.6 acres.
The channel downstream of the Highline Pond, to the west of Pena Boulevard, will need to be monitored to
determine how the channel is being impacted by erosion from pond discharges.
Potential Improvements:
All improvements proposed in the 2005 Master Plan have been built No additional potential capital
improvements were proposed for this basin within the City and County' of Denver reach.
The detention basins proposed in the Irondale Gulch Stormwater Outfall Systems Plan and Preliminary
Design Report, dated May 1990 by Wright Water Engineers have been constructed. The Irondale Gulch
mainstem does not flow through Basin 3900-03 so no recommended crossing improvements apply to Basin
3900-03. Tile Irondale Gulch Outfall Systems Plan Conceptual Design Report was completed in 201 L
Hydrology was updated for the entire Irondale Gulch watershed, including Basin 3900-03. The upper limit
of proposed improvements in the OSP was the Denver/Adams County boundary' and. therefore, no
improvements were evaluated or shown in Denver.
September 2014
Page 82


FILE:Gscjis j]iojcctirilJenvQr[)iaina[ju..?014iactiva^appsWapboDk\2014 SDMP_Mapbnok_No. Ttipo.mxd,tVlS12014, chns_mar1in
0 750 1,500
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
Feet
1 inch equals 1,500 feet
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe -1 Proposed Detention 1 Existing Transit Line
Designed Storm Improvement Basin Existing Basin _~|| City and County Boundary
Existing Surface Flow | 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location 1 Planned Transit Line |!_J ~ Other Counties
Basin 3900-03
Parkfield
Denver Storm Drainage Master Plan
Page 83


Denver Storm Drainage Master Plan
Basin 3900-04 (Irondale Gulch Majestic Commercenter)
Existing Basin Description:
This collection system basin contains the Bolling Drive Tributary and is located in the City and County of
Denver and the City of Aurora. The boundaries of this basin are the southern boundary of Basin 3900-03 to
the north, Picadilly Road to the cast, the northern boundary of Basin 3901-02 and Union Pacific Realty
Company to the south and Chambers Road to the west The basin consists of about 1,181 acres and is mostly
undeveloped with plans for residential, commercial and industrial developments in the near future. The
future subdivisions along the Bolling Drive Tributary include Denver Connection, Gateway Park and
Majestic Commercenter. This tributary also passes through the Pena Boulevard right-of-way. Low flows are
currently conveyed through open channels to regional detention facilities including the Silverado II Pond and
the two Majestic Commercenter Ponds. High flow s are conveyed through the same open channels to the
detention areas. Topography is characterized by generally flat terrain with flows discharging generally to the
northwest toward the proposed Chambers I Pond.
Runoff from the City' of Aurora flows into the City and County of Denver near design point 352. A Gateway
Park residential development will be constructed upstream of this design point within the City of Aurora
Runoff from the Majestic Commercenter will flow through the Gateway Park development
An open channel, the Bolling Drive channel, was recently const me ted downstream of Tower Road to convey
flows from Auroras Majestic Commercenter to the Silverado 11 detention Ponds and into Denver. The
channel was designed for the l{)0-yrear event and was realigned to allow for development. A future culvert
will be con st meted under Tower Road by the City of Aurora.
Identified Drainage Problem s/Deficiencies:
The Majestic Commercenter development hydrologic model has been adopted for this study without revision.
In 2003, Boyle Engineering created an updated model for UDFCD based on information provided by the City
of Aurora. That model information was adopted unchanged at the direction of Aurora, although the base
topographic mapping wras poor. The information was transcribed into Denvers GIS without edits. It was
noted that during the current model update, certain basin areas and model routing from the original
information provided by the City of Aurora could be remodeled to more accurately' match the proposed
conditions. It is recommended that the Majestic Commercenter area be reviewed again to more accurately
represent the flows entering the City and County' of Denver
Potential Improvements:
Storm drain improvements will be constructed commensurate with development to meet current drainage
criteria of l(K)-yrear systems.
Project B: E Bollinu Dr Improvements
An open channel will be needed during development of the area to direct flows from the Silverado II Ponds
to the proposed Chambers I detention Pond. This channel should be designed for the 100-vcar event,
The Silverado M detention Pond proposed in the Irondale Gulch Stormwater Outfall Systems Plan and
Preliminary Design Report, dated May' 1990 by Wright Water Engineers lias been constructed but the
Chambers I Pond has not. The Irondale Gulch main stem does not flow through Basin 3900-04 so no
recommended crossing improvements apply to Basin 3900-04. The Irondale Gulch Outfall Systems Plan
Conceptual Design Report was completed in 2011. Hy drology w as updated for the entire Irondale Gulch
September 2014
watershed, including Basin 3900-04. The upper limit of proposed improvements in the OSP w as the
Denver/Adams County boundary and. therefore, no improvements were evaluated or shown in Denver,
Master Plan Agreements:
Many documents and agreements that specify 100-year discharges and storage volumes have been compiled
for the Irondale Gulch Drainage Basin. Therefore, nothing in this Master Plan shall take precedence over
those agreements or specified discharges. This study' was completed for the purposes of analyzing initial
stonn flows for the 2- and 5-year events.
Agreement 93-04.05, dated April 16. 1995 specifies cost sharing agreements, land use, and the 100-year
discharges and storage volumes for Irondale Gulch, In Basin 3900-04, the Majestic Commercenter Ponds
(Aurora Business Center Ponds), and Silverado 11 Ponds are regulated by this agreement as follows;
Master Plan Design Parameters
ID Peak Peak Detention Jurisdiction
No. Inflow Outflow Volume
(cfs) (cfs) (AF)
Aurora Business Center N/A 393 i 7 Aurora
Silverado II 863 244 65 Denver
After the 1995 agreement, the Silverado 11 Pond was constructed to have 87.2 acre-feet of storage. The
Silverado 11 Pond required modification due to impacts of the new RTD FasTracks East Corridor light
rail/com muter tram The East Corridor Memorandum of Understanding (MOU) between UDFCD and the
Regional Transportation District (RTD) dated August 31,2010 dictates that the required volume of the
detention basin to be 87.2 acre-feet and the maximum surface area of the pond be 27.4 acres.
Page 84


FILE: G:\gie_prej#ets'iDsnvsrDr,ainaga_20l4teetiva,|appsWapbook\20l4_SDMP_MapBook_No_Topo.m:x:d, 9^26/2014, ehris_martin
750 1,500
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
Feet
1 inch equals 1,500 feel
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe ,- Proposed Detention 1 Existing Transit Line
Designed Storm Improvement Basin Existing Basin f|J" _~|j City and County Boundary
Existing Surface Flow | 1 Potential Inundation 11 Area ; Other Municipalities
Significant Flooding Location 1 Planned Transit Line * ~ ~ Other Counties
Basin 3900-04
Majestic Commerce Center
Denver Storm Drainage Master Plan
Page 85


Denver Storm Drainage Master Plan
Basin 3901-01 (Irondale Gulch West Montbello)
Existing Basin Description:
This collection system basin is located mostly within the City and County of Denver. The boundaries of this
basin are 56th Avenue and the southern boundary of Basin 3900-02 to the north. Havana Street to the west. I-
70 to the south and Chambers Road to the East. The basin consists of about 2.096 acres and is mostly
developed with industrial warehouses in the western portion of the basin and residential neighborhoods in the
eastern portion of the basin. Low flows are conveyed within a pipe and channel system, while higher flows
arc conveyed overland through channels and streets. Topography is characterized by general!}' flat terrain,
and there are no regional detention facilities within the basin. Discharge from the basin flows generally to
the cast and north
This basin discharges to the Rocky Mountain Arsenal (RMA) at two points along 56th Avenue. Beginning at
the western end near N. Havana Street, runoff from Basin 3901-01 is collected in an open channel along the
west side of N. Havana Street, crosses 56th Avenue and flows under N. Havana Street to the Havana detention
Pond. The design point for this flow to the RMA is 74. Just to the east of design point 74 is design point 11
where flows from Basin 3901411 are collected in a storm pipe system and arc conveyed under 56lh Avenue,
and discharged into an open channel to the Southgate Pond (also known as the Havana detention Pond)
Identified Drainage Problem s/Deficiencies:
This drainage basin is essentially fully developed with single-family residential properties and
commcrcial/industrial properties. By Denver criteria, the initial storm is a 2-year event for residential areas,
and 5-year for commercial/industrial The Irondale dutch Stormwater Outfall Systems Plan and
Preliminary Design Report. dated May 1990 by Wright Water Engineers states. 'The Montbello area
currently suffers from a lack of adequate capacity for major floods. The existing channels have the capacity
of around the 5-to 10-year flood," In general, the concrete trapezoidal channels can convey flows except for
a few areas.
Potential Improvements:
The 1990 study was completed to upgrade all facilities within the Montbello Area to 100-year capacity. The
greatest constraint was the undersized road crossings over the open channels. By reconstructing these
crossings, major conveyance facilities would be able to convey larger storm events. The Irondale Gulch
Outfall Systems Plan Conceptual Design Report was completed in 2011. Hydrology was updated for the
entire Irondale Gulch watershed, including Basin 3901-01. The upper limit of proposed improvements in the
OSP was the Dcnver/Adams County boundary and. therefore, no improvements were evaluated or shown in
Denver.
Project A: 18 Inch Upgrades
Pipes smaller than 18-inch are allowed only if they are less than 75 feet and only convey flows from one
inlet. These upgrades meet current criteria and provide improved maintenance.
Project B: E 45lh Ave. Improvements
This is an example where the open channel and road crossings cannot convey the developed 5-year flow s.
The channel can be replaced with a 2-102-inchx48-inch RCBC from the Havana crossing to Ironton then a
120-inchx 60-inch RCBC is proposed to continue upstream and terminate at approximate 800 feet upstream
of Design Point 2. For further upstream, the 84-inch. 78-inch and 72-inch RCP w ere proposed to upgrade the
existing pipe to convey the 5-year discharge while 80% full.
September 2014
Project C; E 47th Ave. Improvements
The channel and road crossings cannot convey the developed 5-year flows. The existing box culvert is also
not adequate to convey 5-year flows. The channel can be replaced with a 108-inchx48-inch RCBC in 47lh
Avenue from Havana to Joliet, and a 96-inchx48-inch RCBC from Joliet to Kingston Upstream of the
intersection of 471*' Avenue and Kingston Street to Design Point 24, the existing 60-inchx48-inch RCBC and
48-inch RCP arc also not capable of conveying the 5-year discharge, New 78-inch. 72-inch. 60-inch and 54-
inch RCP arc proposed to upgrade the existing system. Additional laterals should be constructed to reduce
street flow.
Project D: E. 53rd Ave. Improvements
The existing 78-inch pipe is not adequate to convey 5-year flows and must be replaced with a 108-inch
equivalent, The UDFCD outfall system plan assumed some of this flow would be conveyed to the Havana
Lateral, but actually discharges to the RMA. therefore, this study found higher flows to this outfall.
Project E: E. Albrook Dr. Improvements
Existing storm pipe must be upsized to convey runoff to the concrete trapezoidal channels.
Project F: E. Andrews Dr. Improvements
Additional storm laterals should be constructed to reduce runoff in the street during minor storm events,
Page 86


FILE: GAcjis jmiiect^UcnvurDiainac]': ?Ul OactivdSappsWiipbooIrtSSOI-OI .msd, 8fttV2G$4, Dhris_rnartm
Proposed Projects
A- 18" UPGRADES : $1,192,050
B E 45TH AVE IMPROVEMENTS : $20,234,481
- C E 47TH AVE IMPROVEMENTS : $10,862,478
D- E 53RD AVE IMPROVEMENTS : $7,156,629
-E E ALBROOK DR IMPROVEMENTS : $3,221,427
F E ANDREWS DR IMPROVEMENTS : $1,112,782
0 800 1,600
For Detailed Hydrology
See Technical Appendix
and Work Map
Feet
1 inch equals 1,600 feet
a Col lection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe -1 Proposed Detention I Existing Transit Line
Designed Storm Improvement Basin Existing Basin fjj"" _Jlj City and County Boundary
Existing Surface Flow i 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line Other Counties
Basin 3901-01
West Montbello
Denver Storm Drainage Master Plan
Page 87


Denver Storm Drainage Master Plan
Basin 3901-02 (Irondale Gulch Gateway)
Existing Basin Description:
Tliis collection system basin contains the Montbello Tributary and is located in the City and County' of
Denver and Aurora. The boundaries of this basin are the southern boundary- of Basin 3900-04 to the north.
Tower Road to the east. Chambers Road to the west, and 1-70 to the south. The basin consists of about 621
acres and is partially developed with the Gateway Park development and Union Pacific Realty, This tributary
also passes through the Pena Boulevard right-of-way Low flows are currently conveyed through storm pipes
and open channels to regional detention facilities including the three Chambers II Ponds, and the three
Upland Ponds. High flows are conveyed through open channels and through the streets to the detention
areas. Topography is characterized by generally flat terrain with flows discharging generally to the west and
northwest toward the three Chambers II Ponds
Drainage from the City- of Aurora crosses a boundary into the City and County of Denver within this drainage
basin at design points 43 7 and 431.
Identified Drainage Problems/Deficiencies:
This is a newly developed basin and drainage infrastructure has been designed for the 100-year event.
Therefore, no 2- and 5-year drainage deficiencies have been identified.
Potential Improvements:
The Irondale Gulch Stormwater Outfall Systems Plan and Preliminary Design Report, dated May 1990 by
Wright Water Engineers showed detention basins that are regulated by later agreements, as described below-.
Necessary drainage capital improvements w ill be constnicted by the developer to meet current drainage
critena.
The Irondale Gulch Outfall Systems Plan Conceptual Design Report was completed in 2011. Hydrology
was updated for the entire Irondale Gulch watershed, including Basin 3901-02 The upper limit of proposed
improvements in the OSP was the Denver/Adams County boundary and. therefore, no improvements were
evaluated or shown in Denver.
Agreement 93-04.05, dated April 16, 1995 specifies cost sharing agreements, land use, and the 100-year
discharges and storage volumes for Irondale Gulch. In Basin 3901-02, the Upland Detention Ponds, and
Chambers 11 Pond are regulated by this agreement as follows:
M aster Plan design Parameters
ID No. Peak Inflow (cfs) Peak Outflow (efs) Detention Volume (AF) Jurisdiction
Upland Detention Ponds 948 56 42 Aurora UP Realty
Chambers 11 Pond* 663 219 32 Denver UP Realty
*T1ie Chambers II Detention Pond has been constructed and is located between E,
40th Avenue and E, Boiling Drive, east of N, Chambers Road. It is commonly known
as Gateway Park Four Lake as shown on the accompanying map.
September 2014
Page 88


F1L£: Gscjit |}ici]ecti'IJunvr:i[Jininat)i: 2014,uactiYG\appsWapbook\2014_SDMP_Mapbook_No_T[]pci.mxd, B.M9teD14, chris_martin
Key Map


/ \ % o 3900-02
NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
0 600 1,200
For Detailed Hydrology
See Technical Appendix
and Work Map
| Collection System
Boundary
Feet
1 inch equals 1,200 feel
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Existing Storm Pipe Proposed Detention I Existing Transit Line
Designed Storm Improvement ' Basin Existing Basin _~|| City and County Boundary
Existing Surface Flow | 1 Potential Inundation ' Area ; Other Municipalities
Significant Flooding Location I Planned Transit Line (!_J J Other Counties
Basin 3901-02
Gateway
Denver Storm Drainage Master Plan
Page 89


Denver Storm Drainage Master Plan
Basin 4000-01 (Stapleton West Section 10)
Existing Basin Description:
This collection system basin known as Section 10 on the Stapleton site is a tributary to the South Platte River,
and is located entirely in the City and County of Denver. The basin consists of about 476 acres and is
currently undeveloped, except for former runways and storage of crushed concrete. Topography within the
basin is characterized by generally flat terrain. The surrounding area to the north (downstream) of the site is
the Rocky Mountain Arsenal
The basin w as loosely defined in the 1989 Denver Drainage Master Plan and included a portion of north
Stapleton (south of 56lh), as wfell as Adams County (w;est of Section 10). Basin 4400-01 includes all area
south of 56lh Avenue in accordance with the approved Drainage Master Plan for the Stapleton
Redevelopment site, dated March 2001. Therefore, the remainder of this basin lies north of 56th Avenue and
south of 64Ul Avenue.
Identified Drainage Problems/Deficiencies:
In general, there arc currently no trunk storm pipes within this basin. Depressions between die runway's
captured stormwater runoff.
Discharges from this basin into the Rocky Mountain Arsenal must be limited to histone conditions. The
previous study for this basin was the 1995 Stapleton Area Outfall Systems Plan (OSP) by Urban Drainage &
Flood Control District and McLaughlin Water Engineers, which set die following discharge for existing and
developed conditions:
Basin 4000-01
Allowable Discharges from Denver to the Rocky Mountain Arsenal Design Point Peak Discharge
2-Year (cfs) 5-Year (cfs) 10-Year (cfs) 50-Year (cfs) 100-Year (cfs)
OSP Existing Conditions 10* 8 11 12 24 29
OSP Developed Conditions 272* 72 72 72 76 82
Stapleton Master Plan 282** 8 10 10 11 11
Reference Urban Drainage & Flood Control District, 'Stormwater Outfall Systems Plan Stapleton Area July 1995
Reference: BRW, Inc. Stapleton Infrastructure Master Flan Section 5," March 2001
Potential Improvements:
A 100-year retention facility will be constructed commensurate with development for this basin. Establishing
new outfalls through the Rocky Mountain Arsenal would violate previous agreements.
Project A: Pond ZD
The proposed land plan calls for more development than previously included in the Green Book and OSP
Accordingly, a zero dischaige lake (Pond ZD) is proposed to fully store runoff from the 100-year, 244iour
storm. This retention basin will store approximately 51 acre-feet of runoff in a 100-ycar event.
September 20 i 4
Page 9(1


Key Map
.
./ r^i

/v\
Adams County
0058-01
3900-01
1-
Adams County
... %' *!
i
4400-01
Pond 102
68.6 AF
0 600
1,200
For Detailed Hydrology
See Technical Appendix
and Work Map___________
| Collection System
I Boundary
Feet
1 inch equals 1,200 feel
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
^ Significant Flooding Location
Ladora
Lake
Derby
Lake
E64TH AVE
Southgate
Pond

E56TFFAVE-
3901-01
3900-02
- i Proposed Detention
' Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
n City and County Boundary
; Other Municipalities
Other Counties
Basin 4000-01
Stapleton West Section 10
Denver Storm Drainage Master Plan
Page 91


Denver Storm Drainage Master Plan
Basin 4300-03 (Clear Creek North of 1-70)
Existing System Description:
This collection system basin drams to Clear Creek and is generally bound by Regis Boulevard on the south.
Clear Creek on the north and west, and Alcott Street on the east, A 60-inch RCP drains into the basin from
the south from Basin 4309-01 (Berkeley Lake) and continues dirough Willis Case Golf Course and then
along Sheridan Boulevard to Clear Creek The southern half of the basin is located within the City and
County of Denver and drains to an existing 36-inch system in 52ntl Avenue, The northern half is outside of
the City7 and drains to the north into Clear Creek, Tire majority of the basin is residential, but also includes
Regis University- and Willis Case Golf Course.
Drainage Deficiencies:
The 12-inch pipe in Federal, which continues to its outfall in Arvada, is undersized,
The majority- of trunk drainage systems in the residential portions of this basin are adequately sized fora 2-
ycar event.
Proposed Capital Improvements:
Proicct A: N Federal Blvd. Outfall
Replacing the 12-inch pipe in Federal with a 24-to 30-inch line within Denver's jurisdiction will provide a
year level of service. Extending the system to the north into Arvada and the outfall at Clear Creek will
require a 30-to 48-inch line to be coordinated with the City of Arvada.
Project B: Clear Creek Outfall
The existing City and County of Denver storm drain outfall in Sheridan Boulevard should be upsized to
better convey flows to Clear Creek. This is outside the City' and County' of Denver: however Denver has a
30 wide easement for its existing drain in Sheridan Boulevard on to Clear Creek.
September 2014
Page 92


NOTE: Trans-basin flows shown with
a heavy black arrow are based on
existing storm drain systems, not
proposed drainage improvements.
N
0 600 1,200
Feet
1 inch equals 1,200 feet
For Detailed Hydrology
See Technical Appendix
and Work Map
Collection System
Boundary
| Topographic Basin
^ Boundary
! Thalweg
X
Proposed Storm Pipe
UDFCD Study
Recommendations
Proposed Pipe
Disconnect
Legend
Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
Significant Flooding Location
- Proposed Detention
i .* Basin
Existing Basin
Potential Inundation
Area
Planned Transit Line

I Existing Transit Line
Em City and County Boundary
; Other Municipalities
Other Counties
Basin 4300-03
North of 1-70
Denver Storm Drainage Master Plan
Page 93


Denver Storm Drainage Master Plan
Basin 4309-01 (Berkeley Lake)
Existing System Description:
This collection system basin drains to Clear Creek and is generally bound by Sheridan Boulevard on the
west, Regis Boulevard on the north. 35th Avenue on the South,, and the Rocks1 Mountain Ditch on the east.
Approximately half of the basin drains to the intersection of Sheridan Boulevard and 1-70, while the other
half drains to the Tennyson Street and 1-70 intersection. Runoff from these two intersections is conveyed via
large stoim drain systems around Berkeley Lake and to the north across 1-70. Currently, storm pipes cairy
water around Berkeley Lake and do not discharge directly into the lake. Proposed improvements originally
recommended in the 2003 Rocky Mountain Ditch Outfall Systems Planning Study (OSP) included anew
60-inch RCP that would discharge into the lake and alleviate die Sheridan Boulevard and 1-70 system.
However, the 2003 OSP was re-studied by the City and County of Denver in 2005, and die proposed 60-inch
RCP was detemiined to be unnecessary because the existing system was found to be adequate. It should be
noted that the lake was not constnicted as a detention facility, but inadvertent detention docs occur.
Drainage Deficiencies:
The 2005 OSP re-study found die existing drainage system to be adequate basin-wide.
Proposed Capital Improvements:
Based upon the OSP re-studv. there are no capital improvements proposed in this basin.
September 2014
Page 94


FILE: Gntjii jutjwctiMJi:nvoil)iainaga_2D14'tactivatoppsWapbook\2(}14_SDMP_Mapbo[]k.mxdl, 8/1D/2014, chris_martin
Feet
1 inch equals 1,200 feel
Proposed Pipe
Disconnect
Legend
* Existing Storm Pipe
Designed Storm Improvement
--- Existing Surface Flow
^ Significant Flooding Location
Existing Basin
Potential Inundation
Area
Planned Transit Line
I Existing Transit Line
Em City and County Boundary
1 Other Municipalities
Other Counties
Basin 4309-01
Berkeley Lake
Denver Storm Drainage Master Plan
Page 95


Denver Storm Drainage Master Plan
Basin 4400-01 (North Stapleton)
Existing System Description:
This collection system basin consists of 2.468 acres (3,86 square miles) and will be mostly re-built with the
redevelopment of Stapleton, Blueprint Denver shows the entire basin w ithin the City' and County of Denver
as an "Area of Change." The portion of this basin within Adams County does not receive or contribute
drainage from or to Denver, and therefore has generally been ignored for this study. All drainage from this
basin will outfall to Sand Creek.
The majority of North Stapleton historically drained to the Rocky Mountain Arsenal to the north, however
the creation of a Sand Creek outfall near Quebec and 1-270 changed this flow pattern. Large regional
stormwater infrastructure has been built recently as part of the Northfields Mall development. This
infrastructure includes a 9-foot x 7-foot box culvert in 49th Avenue and a 66-inch pipe in 45!h Avenue as well
as a 75 acre-foot detention facility near Quebec and 1-270, Drainage from the 'Northfields Mail
development drains to this detention facility' and then through the new outfall under 1-270 to Sand Creek.
Currently, drainage for the undeveloped areas north of 1-70 flows to the north into the Rocky Mountain
Arsenal. Drainage from the 1-70 corridor and south of 1-70 flows into Sand Creek.
Drainage Deficiencies:
The Sand Creek floodplain significantly encumbers the site between Sand Creek and 1-70, FEMA Flood
Insurance Rate Maps (FIRM) for the Stapleton site shows large floodplain areas resulting from Sand Creek
breaching levees along the river edge. 1-70 is also shown as being inundated during a 100-year flood event in
Sand Creek. The Sand Creek floodplain will eventually become more confined via implementation of the
Sand Creek Master Plan channel improvements.
The King Soopers and Catellus sites exist west of and adjacent to Havana. Since no major outfall exists
today for the area. 100-year retention has been constructed. Runoff is metered out through small storm drains
to allow the basins to dry between storms.
Proposed Capital Improvements:
Proposed capital improvement projects for this basin are being constructed as part of the Stapleton
Development, Park Creek Metropolitan District. A number of previous studies have established the
framew ork for management of stormwater at the site, including die Outfall Systems Plan-Stapleton Area
(OSP), prepared by McLaughlin Water Engineers for the City and County of Denver and the Urban Drainage
Collie and Braden in 1996, the Infrastructure Master Plan prepared by BRW. Inc. in December 2000 and
approved by Denver Wastew ater in April 2001, and the North Stapleton Infrastructure Master Plan
prepared by Matrix Design Group, hie., and approved by Denver Wastew ater in December 2006. The most
current documents are the North Stapleton Infrastructure Master Plan Major Amendment No. 2 prepared
by Matrix Design Group, Inc in January 2012 and die Filing 42 North Stapleton Final Drainage Report
prepared by Matrix Design Group, Inc, in March 2013.
Subsequent to the 2008 Storm Master Plan, additional filings (25. 36,37.39. 41. 42, 43, and 44) have been
submitted and approved by Denver Development Services.
September 2014
Page 96


Full Text

PAGE 2

Collection System Page 0058.01 35 0059-01 37 0060.01 39 0060.02 43 006 1.01 45 0061.0 2 47 0062.01 51 0063.01 53 0064.01 55 0064.02 57 0065.01 59 0065.02 61 0 I-G) ::; 0 (/) ::; I-0 ::; I-CD (f) I-CD ::; CD (f) 0 z z I-1-I-(f) CD --' I-; (/) 0 z <{ --' <{ (f) (f) I-<{ (f) 0 (f) --' cr I-(/) z 0 (f) UJ cr <{ 5 cr >-UJ UJ (/) 0 0 <{ :,( --' 0 ::::; z UJ cr UJ z 0 z (.) cr 0 cr UJ --' I <{ I UJ 0 UJ ::J UJ ::J cr 0 I8 ( I (f) I---' lL N 0.. I CD >(f) 0067.01 63 0067.02 65 0067.03 67 3501.01 69 3700.01 71 3700.02 73 3700.03 75 3702.01 77 3900.01 79 3900.02 81 3900.03 83 3900.04 85 3901.01 87 3901.02 89 4000.01 91 4300.03 93 4309.01 95 4400.01 97 4400.02 99 4400.03 103 4400.04 105 4401.01 107 4401.02 109 4401.03 111 4401.04 113 4500.01 115 4500.02 121 c: 4500.03 117 -e "' 4500.04 119 E "'I 4600.01 123 0 4600.02 125 ... 0 4600.03 129 4600.04 133 .,; 4601.01 137 4601.02 139 4700.01 141 ..: ,.! 4800.01 145 4801.01 145 0 4900.01 147 0 D 5000.01 149 a. "' i 5000.02 151 a. 5000.03 153 5100.01 155 5200.01 159 5200.02 161 0 "' 5200.03 163 .,I "' 5300.01 165 "' c: 5401.01 167 "' 5500.01 169 > c: 5500.02 171 ., 0 ... 5500.03 173 0 "' 5500.04 175 a. 5500.05 177 '!! I $' 5501.01 179 5901.01 iLi 181 -' u: 0 II-cr I-(f) I-(f) 0 (f) I-(f) ::; I-(f) 0 cr (f) (f) 0 <{ CD w 0 0 ::< CD >-<{ ::J 0 UJ ::< 0 --' z --' UJ --' (f) I-CD <( cr 0 0 cr 0 I 5 I ::< ::J 0.. 0 26TH AV E 20 T H AVE COL FAX AVE 1 1TH AVE 6 T H AVE 1ST AVE ALAM EDAAVE EXPOSITI ON AVE M IS S IS S I P P I AVE FWRIDAAVE JEWHLAVE I LIF F AVE YALE AV E HAMPDEN AVE MANS FIEL0 AVE QU I N C Y AVE UNIGNAVE BELL E V IEW AVE Areas with cross-hatching are part of Master P lanned Developments For more information or clarification, contact Development Services STUDY AREA MAP City & County of Den ve r Storm D rainage Master Plan Legend In ters t ate Major R i ver __ .. 1 Studied Collect i on System Boundary I I Unstudied Collec ti on System Boundary f?ZZZJ Master Planned Development Area C::J City & County of Denver Boundary 0 0 2 4 Miles

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D e nver Stor m Drai nag e Mast e r Plan -----------------------------DENVER STORM DRAINAGE MASTER PLAN 2014 PROJECT ID PC70812 908 Prepared for: The City and County of Denver Department of Public Works DENVER PUBLIC WORKS Prepared by: J[ (c(o) N 1 ENGINEERING, INC. 0 E s I G N G R 0 u p I OLSSON ASSOCIATES Septe m ber 2014

PAGE 4

D enve r Stom 1 D rainage M aste r Plan September 2014 Corrections Costrevi se d for pr qjects (09 /29/2 014) : o 3900-04B o 5100 0 1-N o 5200 -03-DD

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D e nver Sto rm D rainage Master Pla n Table of Contents ........................................................... 1.0 .................................................................. 3 1 1 Executive Summary ................... .... ... ........ ...... ........ ...... .............. ............... ........ ...... ........ ........ 3 1.2 Introduction ....................................................... .............. ....... ........ ...... ....... .......... .. ................. .. 5 1.3 Goals ofth e Storm Drain age M aste r Plan ........... .. ...... .. ...... .. .. ........... .. .. ........ .. .. ...... .. ...... .. .. ......... 6 1.3. 1 Management Int ervie"vs ..... .. ..................... ............ ... .. ............. ........... ....... ..... .... .... ................... 6 1.3. 2 Addi tion al Studies ...... .. ....... ...... .. ..... .. ...... .. ..... ........ ......... .. ...... .. ...... .. ...... .. .... .. ...... .. ...... .. ...... .. 6 1 4 Plan Forn1ulation ..... .. ...... .. .... .. ...... .. ...... .. ...... .. ...... .. ....... ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. 7 1 4. 1 Geology ...... ............................... .................................................. ......................... .. .................... 7 1 .4.2 Climate ........................... ............................ .... ... ........ ... ................................................................ ? 1 4.3 Topograph y ......... .................................................. ....... ...... ..... ........... .................. .. ..................... 8 1 4 4 Flood History ...... .. ...... .. ..... .. ...... .. ...... .. ...... .. ...... .. .............. .. .. ... .. ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. 8 1.4. 5 E xisting Conclitio n s .... .. ..... .. ...... .. ...... .. ...... .. ...... .. ....... ...... .. .... .. ...... .. ...... .. ...... .. .... .. ...... .. ...... l4 1 4 6 Futwe Developn1e.nt ..................... ............... ..... ... ............. ........... ..... ........... ........ .... ... ..... ........ 14 2.0 D.RA.INAG EW A ............................................ 14 2 1 South Platte River ( B asin 0000) ...... .. .. .. .. .. .. .. .. .. ...... .. .. ...... ...... ...... .. .. ...... ... ..... .. ...... ...... .. .. .. ............ 14 2.2 Secon d Creek (Bas in 3500) ......... ..... .. .. .. .. .. .. .. ..... ...... ... .. ....... .. .. .. ...... ...... .......... .. ... ..... .... .. .. .. .. .. 14 2.3 First Creek (BasLn 3700 ) ................... ... ........... .. .. .. .... ....... .. ........ .... ....... .. .... .. ......... .. .. .. ...... 15 2.4 Irondale GLtlch (Basin 3900) .. ....... ....... ...... ... .... .... ... .... .. .... ...... ........ ...... .. .. ..... ...... .. .............. .. .. 15 2.5 C lear Creek ( Basin4300) ............ .. .. ...... ..... .. ...... .. ...... .. .............. .. .. ........... .. .. .,. .. .. ...... .. ...... .. ...... .. .. 15 2 6 Sand Creek (Basin 4400) ..... ... .... .... ................................ .......................................... .... ................ 15 2 7 Westerl y C reek (Basin 4401 ) .............................................. .. .. .. .. .. .. ... ......... .......... .. .. .. .. .. ..... ...... ... 15 2 8 Montc l ai r (Basin 4500) ....... .... ... ............. ......... ....... .......... ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. ...... .. ...... 16 2 9 Cherry Creek ( B asin 4600) .............. ....... ....... .... .......... ....... ....... ....... ................... ................... 16 2 1 0 Goldsmith Gulch ( Basin 4601) ................ ........... ... ..... .. ...... ... .. .... ...... ... ..... .. ...... ... ..... .. ...... .. ...... .. .. 16 2.11 Sloans L ake (Basin 4700) .. ... ..... .. .. ................... .. .. ....... ............... ........... .. .. ........... .. ....... .. ....... 17 2 12 Lakewood Gulch (Basin 4800) ...... .. ...... .. ...... .. ...... .. ...... ..... .................................... ... .. ...... .. ...... 17 2 1 3 Dry GuJch ( B as in 480 I ) .. .......... .. .. .. .. .. .. .. .. ........ .. .. .. .. .. .. .......................... ........ ........ ......... .. .. .. .. ...... 17 2.14 W eir Gulch (Bas in 4900) ............ ... .......... ........... .. ...... ....... .... ........... .. .. ................... ....... .. ...... .. .. 1 7 2 .15 Sanderson Gulch ( B asin 5 1 00) .. .. .. ... .. .. .. ... .. ... .. .. .. .... .. .... .. ........ .. .. .. ........ .. .. ........... ..... .. .... .. 17 2 1 6 H arvard G11lch (Basin 5200) ....................... .. .................. ................................ ........... .. .............. .... 17 2 17 West Harvard Gulch (Basi n 5300) .. .. .. .. .. .. .. .. .. .. ...... .. ...... ....... .. .. .. .. .. ...... .. ...... .. ...... .. .. .. .. .. ...... .. .. .... 18 2 18 Bear Creek (Basin 5500) ...... ... ......... .................... ...... .. ..... ................ ...................................... 18 2.19 Marsto n Lake North (Basin 550!) ...... .. .. .. .. .. ........ ..... ..... .. .. .. .. .. .. .. ... ..... .. .. .. .. ....... .. ...... ....... .. .. .. .. 18 3.0 CAPITAL ................... 19 3 1 Cost Modeling .................................................. .. .... .......... ............ ... .............................. .............. 1 9 3 2 Swnmary of Capital Costs .......... .......... .. .. .. .. ....... ...... ... ..... .. .. .. .. .. ....... ...... ... .... .. .. .. ...... .. .. .. .. .. .. .. 19 4.0 .................................................... 26 MAPPlNG Study Area M a p lndex Map Areas of Change Ma p Coll ection Sys t em Maps September 2014 TECHNICAL APPENDIC ES for each collection system (under separa t e cover) Impet viousness Com p ut ations R ou tin g Schemat i cs CUHP Model Input/Output UDSWM Mode l Input/Output Work Maps (Co lor 1-inch = 4 00 Aerial) Detailed Pr oject Cos t s Page 1

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D e n ve r Stonn Drain age Master Plan ACKN OWLEDGMENTS The project team w i s he s to acknowledge the various individuals in the City and County of Denver who assiste d in the preparation of this update to the Stann Draina ge Master Plan study for the C it y and County of Den ver : Michael Anderson Den ve r Publi c Works Walt Hime D evelopment Services Saeed Farahmandi Denver Publ ic Wotks Lupe Martinez, D enve r Public Works Bruc e Uhernik, Denver Publi c Works Kimberly Watanabe Den ver Public Work s The folJowing members of the consultant project t ea m contrib uted significant time and effon to the preparation of this upda ted ma ste r plan report: E n g inuity E n g ineering Solutions, LLC Team: Don J acobs Project Manager B eck Anderson Jeff S i ck l es ICON E n g ineering, Inc. Te.am: Craig Ja cobson Project Manager E b e n Dennis Bria n LeD oux Mat.-ix Design G.-oup Inc. Team: R o b eti Krehbiel, Project Manager HungTen g H o Jeff C l o n ts Chris Martin Wilson Wheeler Olsson Associates Team: Deb Ohlin ger Project Manager Amy G a bor David Krickbaum Ja son Messamer Sao E ngineering, LLC John D inkel Eduardo San Zoeller Co nsulting, LLC Lisa Zoelle r S ep t e mber 2 0 1-f Cover Pho to Credits : Cove r design by Jan ae Newma n Graphic D es i gn-O l sson Associates Cover I mage : Copyright Thinkstock 20 1 4 down l oade d using Ol sson A ss oci ate s s u bscriptio n l ice n se May no t be u sed in oth er material s Other I mages : Historic : d ate and source unkn own Fir e Trucks: date an d source unknown August 2002 : source unknown A ugust 18, 2004 : source unknown Septe mb er 1 2 2013 : T ony Ryan P age 2

PAGE 7

Denver Storm Drainage Master Pian l.O BACKGROUND l.l Executive Summary In accordance with Denver Revised Municipal Code Division 4 Section 56-110, Denver s Storm Drainage Master Plan is updated every 5 years in order to identify and alleviate present and future drainage probJems of the city Consequently, the plan is subject to regular modifications and holders of the plan are therefore encouraged to contact the City and County of Denver Department ofPublic Works Engineering Division Capital Projects Management Group for the most currently available information Drainage basins at Denver International Airport (DIA) have been excluded from this update in accordance with DIA s independent implementation of its own storm drainage and water quality infrastructure Urban stormwater management within the City and County of Denver has increasingly become a critical infrastructure element as major improvement programs and asset re-development efforts are implemented across the City The improvements identified herein form the basis for identifying needed storm drainage capital projects throughout the City in its Capital Improvement Program. The total project cost to upgrade the City s storm drainage infrastructure, to meet minimum current drainage criteria in the Recommended Plan for the entire City is estimated to be $1, 478 025 513 in 2013 doUars This Master Plan updates and refines the previous Stonn Drainage Master Plan to incorporate recently-constructed storm drainage facilities and the findings and recommendations of various studies conducted in the years following publication of the last Storm Drainage Master Plan In addition this update identifies topographic drainage basin boundaries and thalwegs Potential Inundation Areas where localized floocling in excess of street drainage criteria is possible and Significant Flooding Locations reported since the year 2000 This update also identifies locations of flood control improvements needed along drainageways in studies conducted by the Urban Drainage and Flood Control District (UDFCD) in partnership with the City and County of Denver Drainage Basins and T h a l wegs Hydrologic modeling of the existing storm drainage system reveals that two distinct drainage basins exist: 1) Storm Drainage Collection System Basins defined by the existing storm drainage collection system catchments for minor storm conveyance designs, and 2) Topographic Drainage Basins defined by overland tlow paths related to larger stmm events Both are shown in the Master Plan in order to clearly illustrate where storm drain systems direct storm runoff for the minor storm event and where larger storrn events will produce surface runoff crossing coHect:ion system boundaries. In addition, thalwegs, or natural drainage paths, are shown in order to identify the major overland flow paths that storm runoff would follow in storm events tl1at produce runoff in excess of the existing storm drainage collection system capacities Not all thalwegs are shown, only the most significant for each drainage basin September 2014 Potentia l Inundation Areas Potential Inunda tio n Areas (PIAs) shown in the Storm Drainage Master Plan are areas where stormwater has been reported to collect in depths exceeding 12n during storm events and where various studies have identified the potential for water depths greater than 12 in a major storm event. The areas depicted represent current best-available information of these hazards PIAs are shown so that the information is accessible to Denver residents and property owners PIAs are not to be confused with floodplains mapped in accordance with Federal Emergency Management Agency (FEMA) guidelines for the National Flood Insurance Program (NFlP). PIAs are identified due to more localized flooding issues and are not shown on the NFIP Flood Insurance Rate Maps and therefore flood insurance is not federall ymandated and most floodplain specific regulations do not apply. However it is important to note that in the absence of better available information, the flood depths defined in PIAs may be used to determine the Finished Floor Elevations (FFE) and Minimum Lowest Opening Elevations (MLOE) for new development andredevelopment. Property owners in PlAs are encouraged to implement floodproofing measures (see the City and County of Den ve r Flood Protection Handbook at www.denvergov. o rg/ta bid /3 91460/Defau l t.asp x ) and explore the need for flood insurance since flood damages are not covered by a typical homeowner policy A separate flood insurance policy is required to cover contents that may be damaged due to flooding. Property owners can insure their buildings and contents, and renter s can insure only their contents Additional flood insurance information is available at www.floodsmart gov These areas do not reflect all such hazards throughout the City and County of Den ver but represent the best available information based on flooding reports and drainage studies Other areas may be identified in the course of additional more detailed studies and storm events. Significant F l ooding Locations Significant Flooding Locations shown with red stars are locations where significant flooding and /or property damage have been reported since the year 2000 to the City and County Department of Public Works-Storm Drajnage Plannjng and have not yet been mitigated with storm drainage improvements. They do not reflect all reports received only the most severe. UDFCD Study Recommendations The location of flood control improvements identified in Major Drainageway Planning studies and Outfall Systems Planning studies conducted by the UDFCD are identified in order to better coordinate work efforts by the Public Works storm drainage Capital Improvement Program the Public Works bridge Capital Projects Program., Department of Parks and Recreation improvement s and the UDFCO Hydrologic Modeling for the existing storm drainage network was conducted using the Colorado Urban Hydrograph Procedures (CUHP 2000) and the Urban Drainage Storm Water Management Model (UDSWMM) version 1.4.6 developed by the UDFCD Modeling from more recent studies was conducted using CUHP 2005 and EPA Storrn Water Management Model (EPASWMM) ve rsion 5.0.022. Results have been incorporated into this update in some drainage basins in order to retain the updated modeling from those studies The resuJts were then used to identify areas where Page 3

PAGE 8

Denver Storm Drainag e Master Plan existing stonn drainage systems needed to be enlarged to meet the current level of service and where new stonn drainage systems were needed. Land-Use impervious values are based on Blueprint Denver: An Integrated Land Uu ami Transportation Plan adopted in 2002 as a supplement to the Denver Comprehensive Plan 2000 (herein referred to as "Blueprint Denver "), which prepares the City for continued urbanization and redevelopment by identifying'' Areas of Stability and" Areas of Change This i nfonnation i s supplemented with surface area impervious data available in Denver's GIS database Also the City has implemented a myriad of stonnwater management programs to comply with the Municipal NPDES permit including inventorying the stormwater systems and construction of local and regional Best Management Practices (BMP 's). One of the major goals of this updated plan is the integration ofthese documents ru..1d programs into a comprehensive Public Works management program Adaptive Urban Stormwliter Management and Level o(Service Tradjtionally drainage in the Denver Metropolitan Area has been managed with a combination of underground storm drains overland flow conveyance elements (e.g. roads and channels) and regional detention facilities Currently it is Denver s policy to require drainage systems design to confonn with the Level of Service goal of fully conveying at a minimum, the minor or initial storm event within pipes or channels. Minor or initial" storm is defined by the Denver Drainage Criteria as a 2-year storm e v ent fur residential properties and the 5-year storm e v ent for commercial and industrial districts Runoff from storm events exceeding the minor storm up to the 1 00-year storm is conveyed in streets up to l foot deep in the gutter or in surface drainageways. Open channels, gulches streams rivers and creeks are designed to convey the 100-year storm event. As the City and County of Denver continues to densify land values have increased resulting in higher easement and right-of-way costs for open channels Also, parks and other open space areas continue to be improved to provide a more active and urban setting that limits the availability of storage for stonnwater detention The City will continue to evaluate redevelopment areas for land acquisition for regional detention facilities to reduce peak flows. The conveyance system must accommodate ru1d improve the Level of Service provided by City drainage int!-astructure. Overview of Curre 1tt Svstem Def iciencies The Stonn Drainage Master Plan evaluates the capacity of the City s existing storm drainage system compared to predicted storm runoff rates for the minor storm event Within a majority of the older sections of the City and County of Denver the existing storm drains provides flood protection for between a land 5 year storm event. Runoff generated from larger storm events is temporarily stored jn streets and ultimately conveyed to gulches and streams via the combination of roads and storm drains when capacity becomes available Complaints records maintained by the City since 2000 indicate a number of locations where surface storm runoff e x ceeds the City s street depth criteria of 12-inchse of flow in the gutter and significant flooding and /or property damage have been reported. For this Master Plan only the most significant flooding locations have been identified Initial hydrologic models show that localized storage which exists within the City provides important flood flow attenuation and as a result it is important to phase improvements from downstream to upstream to avoid eliminating storage that would increase peak discharges upon downstream existing systems. S epte mb e r 2 0 Existing storm drainage infrastructure was considered deficient if the minor-event flow was greater than 100% capacity of the infrastructure. Proposed infrastructure was designed to be 80% full when conveying the minor-event flow Approliclzes to Prol' iding an Upgraded Drainage Svstem The following criteria are used to evaluate storm drainage improvements : Maximize level of public safety and property protection Ensure compatibility with Blueprillt Denver E11sure compatibility with projected year 2020 land uses and needs Minimize negative environmental impacts such as 404 Permitting, NPDES Permitting, and other Clean Water Acts implications Maximize opportunities for water quality enhancement Minimize life cycle costs Support and be compatible with current capital improvement program for drainage and other PubJjc Works programs Encourage and enable development participation Provide flexibility in phasing Minimize drainage impacts to transportation facilities especially intersections and high capacity roadway systems Minimize construction impacts to already developed properties Provide multi-means and multi-use facilities to the maximum extent possible, .and Provide a document that is rational and likely to foster public and political support for drajnage improvements Cost effective implementation of a City-wide I 00-year drainage system is not practical because of the significant capital cost of retrofit construction and limited annualized flood hazard reduction Consequently a phased progrrun is recommended that prioritizes improvements to address cun-ent hazards while improving the minor storm system This Stonn Drainage Master Plan identifies capital improvements based upon the hydrologic modeling and the Level of Service goal. In many cases meeting this goal requires upsizing an existing pipe by one or two pipe sizes. This master plan shows the capital improvement as a basis for evaluating prioritizing and designing caphal improvements It is not intended in all cases to recommend removing the existing pipe and replacement with a larger pipe. Value engineering (beyond the scope of this Master Plan) will evaluate the condition of the existing pipe potentially propose a parallel pipe, determine whether additional flow can be carried in the street identify a new outfall and /or accept existing conditions where the cost/benefit ratio is less than one The proposed capital improvements, in general, are shown as complete replacement with a round pipe with conveyance capacity for the appropriate level of service based upon existing land use Conflicting utilities and other constraints will necessitate drainage infrastructure equivalents such as box culverts elliptical pipe or open channels The assumed slope of the proposed pipe is either the srune as an existing pipe, street grade or at 0.50%. Proposed pipe 48-inch or greater has been profiled as part of this Master Plan update and are included in the Technical Appendices. Slopes are chosen to avoid utility conflicts. Shallower slopes detennined during preliminary design may necessitate larger pipes/box culverts Page 4

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D e n ve r Stonn Drainag e Mast e r Plan Denver's drainage criteria require all storm pipes to be reinforced concrete pipe (RCP) Many of t h e older existing drain pipes were constructed with brick or other materials s uch as vitrified clay pipe (VCP) Evaluat in g t h e material or age of existing pipes i s beyo n d the scope of this project a nd repl acement is based upon capacit y rather t han condition. Den ver ma i ntenan c e force s wm need t o compile a separate inve ntory of capital impro v ement s based upon pipe degradation All e x istin g collector stonn pipes must be 18-inch diameter or l a r ge r accordin g to D enver D rainage Criteria (15 -in c h p i p e is allo we d only if no more than one i nlet i s connected t o the pipe ) Therefore all s torm pipe s le ss t han 1 8-inch di a meter and l onger than 1 00-feet (assumed t o r ep r esent collector pipe s rather than late ral s) have been queried in the GIS a nd show n in this cap ital improvemen t program as Teplacement w ith new 18-inch RCP 1 2 In troduction This publica t ion i s prepared in comp li ance with Denver Revi sed Mwu c i pal Code Divi s ion 4 Stor m Draina ge, Section 56 -110 Master Drainage Plan The do c ument incorporates the p rac tic es and principles of Volumes I and It of the Urban Drainage and Flood Contro l Dis trict ( UDF C D ) Drainage Criteria Manual a n d City and Co unty of Den ver St()rm Drainage Design and Technical J lfanual. Thi s Stonn Master Plan updat es the p r e v ious publication with new info rmati o n incl u ding: 2008 Li.DAR t opograp h y Additional As-Built storm drain i nfr as truc tu re data forrecently cons truc te d project s Top ogra phi c dr a inage b a s i n boundati es and tbal wegs Potential Inund a ti o n Areas Sig nifi cant flo o din g l oc ation s UDFCD s tud y recommendations This update proces s includes all of the City and County ofDenver, except DIA and prov ides a detai l ed eva l uation of h y drolo gic co ndition s a nd cqnceptua lleve l design of draina ge impr ovements w ithin the f o llo w in g ba s ins: ID OUTFALL NAME/ LOCATION AREA FUTURE LAND USE (mi 2 ) COMPOSIT E IMPERVIOUSNESS 0058-01 South Platte River Pralrie Gatewa.y 1 58 40 65% 0059-01 South Platte River Globevil l e Utah Junction 4.07 64. 50% 00600 1 South Platte River 1-70 & Colorado Boulevard 2.14 64.42% 0060-02 South Platte River 1-70 & York 1.46 64 53% 0061-01 South Platte River 27th & Federal 2 23 56.44% 0061-02 South Platte River Highland 2 .9 8 57 .87% 0062-01 South P latte River Lower Platte Valley 2 73 74 04% 0063-0l South Pfatte River Central Platte Valley 2.03 73 75% 0064-0l South Platte Rive r 1 st & Federal 0.44 64 .7 0% 0064-02 South Platte River Valverde 2.65 61. 14 % 0065-01 South Platte River Ruby Hill 1.25 55.45% 0065 -02 South Platte River Dartmouth 0.76 86. 86% 0067-01 South Platte River College View 1 29 55 17 % ID 0067-02 0067-03 3501-D1 3700-D1 3700-D2 3700-D3 3702-01 3900-01 3900-02 3900-03 3900-04 390. 1-01 3901-02 4000-01 4300-03 4309-01 4400-D1 4400-D2 4400-D3 4400-04 4401-03 4401-04 4500-01 45'00-02 4500-03 4500-04 4600-D1 4600-'02 4600-03 4600-D4 4601-01 4601-02 4800-01 4801-01 4900-01 50 00-01 5000-02 5000-03 5100-01 5200-01 5200-02 5200-03 5300-01 5401-01 September 201-t OUTFALL NAME/ L OCATION AREA FUTURE LAND USE (mi2) COMPOSITE IMPERVIOUSNESS South Platte River West Belleview 4.21 49 65% No Outfall Marsto n Lake 1.06 93 76 % Second Creek West Fork Second Creek 3.45 41. 05% First Creek First Creek & Peiia Corridor 2.23 52 09% First Creek First Creek Green Valley Ranch 2 1 2 48 92% First Creek First Creek Dogwood & Blue Gram a Tribs. 2.61 6 1.13% First Creek First CreekTributarv 'T' 0.91 68 56% I rondale Gulch Irondale Gulch -Stapleton 0.22 48 00% Irondale Gulch Irondale Gulch East Montbello 1.91 47 55% Irondale Gulch Irondale Gulch Parkfield 2.93 61. 83% Irondale Gulch Irondale Gulch-M a.jestic Commerce Center 1 .85 76 52% Irondale Gulch Irondal e Gulch West Montbello 3.27 66 50% lrondafe Gulch Irondale Gulch GatewaY 0.97 60 25% Rockv Mountain Arsenal Stapleton West Section 1 0 0.74 34.02% Clear Creek C l ear CreekN o rth of 1-70 1.81 50 39% Clear Creek Berkeley Lake 1.83 46 59% Sand Creek North Stapleton 3 .8 6 62 74% Sand Creek Quebec Corridor 4.41 62 55% Sand Creek Stap leton 1 ,51 66 79% Sand Creek East 1.90 66 10% Westerly Creek Westerly Creek South Stapleton 3.01 49 09 % Westerly Creek Westerly Creek 11th Avenue to Montview 1.06 59 36% Westerly Creek Westerly Creek Lowry 3 98 41. 74% Westerly Creek Westerly Creek South of Alameda 2.85 65 09% Montclai r City Park 4 .26 46 52% South Platte 36th & Downing 1.74 56 .3 9% Montclair Park Hill Colfax 1.52 52 20% Montclair Park Hill -6h Avenue 3.65 45.44% Cherry Creek Central Business District 2.23 72 56% Cherry Creek Cherry 'Creek Mall 4 .57 52.40% Cherry Creek Upper Cherry Creek 5.60 65 27% Cherry Creek Cher_ry Creek Reservoir 5.74 49 99% Goldsmjth Gulch Lower Goldsmith Gulch 4 .04 5 1. 1 3% Goldsmith Gulch Midd l e Goldsmith Gulch 1.34 64.43% Sloan's Lake S l oan's Lak-e 1.58 57. 88% Lakewood Gulch 1 2th & Federal 1 18 51. 58% Dry Gulch 1 2th & Sheridan 0.39 62 00% Welr Gulch Weir Gulch 2.38 50 39% & South Platt e West Washington Park 1.23 63 66% 1-25 Unjversitv & Mexico North 2.81 54 35% Florida Uni vers ity & Mexico South 2.29 51. 24% Sanderson Gulch Sanderson Gulch 5 .56 49.45% H arvard Gul ch Harvard Gulch Lower Basin 0 .85 54 72% Harvard Gulch Harvard Gulch Middle Basin 2 75 47 38% Harvard Gulch Harvard Gulch Uooer Basin 3.84 51. 11% West Harvard Gulch West Harl.!ard Gulch 1.44 52 34% Greenwood Gulch Greenwood Gulch 0.17 73 66% -P age 5

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Denver Stonn Drainage Master Plan ID OUTFALL NAME/LOCATION AREA FliTURE LAND USE (mi2 ) COMPOSITE IMPERVIOUSNESS 5500-01 Bear Creek Bear C reek Fort Loaan 3.11 53.57% 5500 02 Bear Uppe r Bear C reek 1.86 44.34% 5500 -03 Bear Creek Academv Park 0 .60 62 66% 550 0 04 Bear Creek Bear Cree k Marston Lake North 2 .23 43.98% 5500 05 B e ar Creek Pinehurst Tributary 0.71 42 08% 5 501-01 B e ar C reek He.nrv s La k e 1.36 35.03% 5901 -01 Dutch Creek Coon C reek 3 .10 53.67% 1.3 TOTAL AVERAGE Goals o f the Storm Drainage Master P l a n 15 4.41 56.88% 1.3.1 Nlmutgement I nteniews To provide direction to the planning process and capitalize on the extensive e x perience and knowledge of staff, selected members of the City Public Works and Planning Departments were interviewed in 2002 and 2003 The following issues goals obstacles and measures for success were identified : PritJutTJI Draitzage I ssues Co11frontitzg th.e City In many areas, the e x isting City drainage system does not meet current drainage criteria whereby the initial storm (2-year recurrence for residential areas and 5-year recurrence for commercial / industrial areas) cannot be fully conveyed within p i pes or dedicated d r ainage channels In other w ords the current drainage system is generally undersized except for the major drainageways which have been improved over the years (e g South Platte River, Guldsmith Gulch Harvard Gulch) {tis impractical and prohibitivel y expensive to upsize the storm drain system on a City-wide basis to provide for a 100-year storm The Master Plan needs to understand the imptications of redevelopment. Major projects such as Stapleton or Lowry benefited from scale economies and private-sector de v eloper investments to construct new improvements to outfall to major drainageways. Smaller redevelopment projects such as those within North Cherry Creek basin or Jower downtown lack the financing and cohesion to build regional drainage systems and Because the existing drainage system consisting of a combination of stonn drains and surface street flow does not strictly satisfy lOO-year standards City staff must review waiver requests on a regular basis and need a decision-making tool for evaluating the reasonableness ofproposals. Goa l s (or the Master Plan Upda t e Process Provide a regularly updated guidance docwnent to identify storn1 drainage capital projects needed to mitigate flood risks and losses Create optimal value with the master plan to capitalize on available revenues from the drainage enterprise fund while providing the greatest reduction in flood hazards Ensure that facilities are designed to be maintainable, and that a commensurate budget for on-going maintenance and new storm drain construction is anticipated and provided for S ep t e mb e r 2 0 Encourage the use of multi-purpose facilities such as incorporating linear parks within riparian corridors and co-locating detention facilities within other municipally owned properties or parks Provide a tiamework nocument that informs developers of potential drainage deficiencies within project areas so that pmperty values reflect the risk of flooding or level of capital inveshnent required to address stormwater management issues Provide a toolbox for reviewing development proposals, including access to background information used in the plan and hydrologic models that may be modified by staff as more specific development proposals are made within each and Provide atiamework for continued urbanization of the City and County ofDenver and implementation of the concepts and tenets of Blueprint Denver: An Integrated Lmul Use tmd Ttam,portation Plan Thr eats or Obstacles Prete t zting Detzver From Obtaining Tltis Goal The relatively short timeframe and broad expanse of the study area poses a major challenge to evaluation of the basins in a street-by-street detail. Hydrologic modeling should be developed in sufficient detail to support the conceptual design and sizing of infrastructure There shouJd not be an effort to develop new technology or precisely define urban floodplains Because the City has limited enterprise funds for construction of new facilities a 100-year storm drain system will likely be unachievable in most drainage basins The plan needs to establish a rationale for appropriation of funds based upon current level of service drainage criteria Appropriate Arleasnre (or Success o(the Update Process Completion of the Master Plan with enough detail to v alidate or justify modification of the City' s current Capital Improvement Program (CIP), Establishment of a framework for screening options and supporting a preferred plan for implementation, and Creation of a document that is usabJe and provides for continued update by the City s GIS and stoon drainage master plan update processes 1.3 2 AdditiOilal Studies ln accordance witl1 Denver Revised Municipal Code (DRMC) Section 56-11 O(c), the City and County of Denver as a matter of course conducts addhional studies as may be necessary to detem1ine the most cost-effective approach and the estimated costs of constructing the drainage facilities shown on the master plan which do not presentl y e x ist. Page 6

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Denver Storm Drainage Master Plan 1.4 Plan Formulation 1. 4.1 Geology The City a n d County of Denver is built across the deepest part of the asymmetrical Denver bas in Most bedrock outcrops in Denver consist of the Denver formation of Paleocene Age although the Arapahoe Formation of Cretaceous Age outcrops in the low areas near the South Platte River. These two formations are sim i lar in lithology and were deposited as a result of alluvia l action torrential floods and dilation in quiet lake s Overlying the bedrock swface at most places is a relatively thin covering of unconsolidated surficial materials composed of boulders cobbles, grave l sand silt and clay. The surficial alluvial material making up the floodplain and terraces of the South Platte River is predominantly sand and gravel with some silt and clay beds Geologic maps clearly identify ancient and historic alluvial stream beds prior to the se drainageways being f ill ed in by development. Figure 1 illustrates the bedrock topography for the downtown area of the South Platte River, Cherry Creek, and Sand Creek. This map identifies a paleo-channel alignment of Cherry Creek primarily through what now has been defined as Basin 4400-02 1.4. 2 Climate The Lower South Platte drainage area experiences a climate commonly known as a semiarid continenta l type The area is characterized as a zone of transition from a plains to a foothills climate. The area has cold dry winters and cool, relatively dry summers Typically there are low precipitation rates and humidity, pronounced variations in diurnal and seasonal temperatures, and periods ofhigh w inds. Average annual temperature is around 49 F with a recorded high on June 25, 2012 of 105 F and a low of -30 F recorded in 1936. Diurnal temperature fluctuations usually range from 26 to 29 F for most months; howe ver around July daily fluctuations can be much greate r A wide average range in daily temperatures i s typical of the high plains Extremely hot weather in summer or extremely cold weather in winter generally does not last long and is followed by more moderate temperatures. Annual precipitation averages about 15.8 inche s. More than two-th ird s of the precipitation falls from April to September which is the average annual growing season. On average Denver experiences about 75 storm events annually Of these 75 events about 46 on an average annual basis produce le ss than 0.1 inch of precipitation About 22 of the remaining 29 runoff-producing average annual events total between 0.1 inches and 0.5 inches of precipitation. Typically Denver experiences only 7 large storm events (greater than 0.5 inches) annually These significant storm events are characterized by short duration high-intensity r ain showers that overwhelm the existing dra ina ge system for several hours. Figure 1: Geohydrology Map (Robinson 1996) of Downto w n Denver showing bedrock contours and evidence of historic channel alignments. The map shows Cherry Creek once flowed throug h Basin 4400-02 between Quebec and Colorado Boulevard -mo -A--A' September 2014 Bl'drodc oulol Yllleyo In turloc.Une P411tm tndlcalt> paleovolty, Btdrodcourflot tonlourShowa approxlm&lf. olliiUde o f btdrod< Mtac. underlying uncocnolda!td Mdlmtnl 06slltd whirrlnftnd Hockurfllndleolr dtpmslon ftalurn ConiOilr lnltrval 20 (tti lndtl CODIOUI ltllttvAI I 00 h!
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Denver Stonn Drainage Master Plan The driest months are December through January. Average annual snowfall at Denver is about 59 inches. Humidity averages about 39% during the day and 62% during the night. Humidity i s sJightly higher in winter than in summer. The sun shines approx im ately 69% of the possible sunlight hours annually. Wind speed averages about 5.9 mph, and upslope winds predominate from the south and west An average wind speed is not adequate to describe conditions in the area Low wi nd conditions have been experienced and often contribute to air poll uti on problems. High velocity winds often destroy trees, crops and structures and winds in excess of90 mph have been recorded 1.4.3 T opogntph.y The South Platte River Drainage Bas1n can be divided into a plains r egion and a mountain region The pla in s exh ibit a trellis drainage pattern ; streams flowing in alluv ial chan n els. The mountain regions are characterized by a dendritic drainage pattem. The Lower South Platte drainage area topography represents flat to gentle undulating plains with e l evations r anging from 5 ,650 feet in the southeast to 4 950 feet in the floodplain of the South Platte River. Drainage from the west flows easter l y from the foothills into tributaries of the South Platte River. On the east side of the South Platte River in the Denver area major drainage flows l ead from southeast to northwest by way of Cherry Creek Sand Creek and Harvard Gulch 1.4.4 Flood History The City and County of Denver and surrounding metropolitan areas lie within the watershed of the South Platte River. Development has occurred within the geomorphic floodplain and has taken place in areas prev iously devoted to gardening and fanning. Residential areas within the historic floodplain include Globeville Valverde and scattered smaller deve l opmental areas. Numerous flood contro l a n d mitigation measures have been implemented throughout the years to reduce the flood hazards. l n 1901 Mayor Speer suggested constructing walls along Cherry Creek the first ordinance was passed in 1908 and construction was comp l eted in November 1915 A Cherry Creek F lood Commission was appointed in 1912 and recommended a dam with reservoir capacity of 12,000 acre-feet. However the Castlewood Dam built on Cherry Creek in 1890 failed in August 1933 After the 1933 flood C i ty offic ial s decided to build a flood control dam at Kenwood A l so during this time, Works Progress Administration (WPA) workers straightened and riprapped the Cherry Creek banks In 1950 the U.S. Army Corps ofEngineers completed Cherry Creek Dam 1 ,000 feet upstream from Kenwood Dam June 1965 was a notabfe period of severe flooding around Denver. Following the t1ood several steps were taken to mitigate the effects of flooding fiom suc h an event. Congressional support was sought to build Chatfield Dam as a flood control structure for the South Platte River. The Mayor of Denver constituted a South Platte Ri ver Dev elopment study group to develop a plan for the Platte River Valley t hat would incorporate various flood control measures Several priva t e grou p s in the community organized themselves to provide support for the planning effort The preliminary report for Chatfi e l d Dam was issued in December of 1 965 and construction was completed in 1973 The following is a summary of the major storm and flood events in the Denver metro area: September 2 0 1-J May-June 1844-The earliest flood for which circumstantial evidence is available occurred in 1844. The bottom lands in the vicinity of Denver were covered in water extending from the bluff on Cherry Creek to the extreme bluff on the South Platte River accord in g to Major James Bridger in a June 22, 1864 article in the Denver Commonwealth May 19 20, 1864 -Heavy rain over the upper basin of Cherty Creek caused 19 deaths along Cherry Creek and the South P latte River in Denver. The flood from May 18 combined with this flood and covered the lower sections of the City with l to 5 feet of water. The flood washed out several bridges and swept large buildings off their foundations Property damage from the flood was estimated at approximate l y one million dollars July 14 1912-A thunderstonn with heavy rain in the late afternoon combined with a similar stonn south of the City to produce widespread flooding on Cherry Creek in downtown Denver and resulted in two deaths The flooding in Denver was the worst since 1 864 and covered approximately 3 square m iles of lower downtown. Bridges along Cherry Creek were washed out and water lapped at the floor of the Broadway Bridge over the South Platte The floodwater caused great damage to t h e drainage system parkways bridges and to residences and commercial warehouses near C h erry Creek. Flood damage was estimated at several million dollars May 21, 1914-A severe thunderstorm produced heavy rainfall of0.83 inches in 15 minutes. Flooding caused considerable damage to bottomlands in eastem and southern parts of Denver. June 2-7, 1921-During April the snowfa ll had been unusually heavy approximately three times its normal depth for that month Rainfall measurements in the footh ill s ranged from 3 to 5 5 inches from Jun e 2 through 7. The Sout h Platte River in the canyon reached a stage of9 feet and washed out the tracks of the Colo r ado and Southern Railroad The bottomlands in the valley below Denver were tlooded with the overflow being as much as 4 miles wjde near Sterling The overflow reportedly stretched th e 43 miles from the mouth of the canyon to Denver. August 2-3, 1933 -3 to 9 inches ofrain in 9 hours caused Castlewood Dam on Cherry Creek to fail. Seven people died in Denver. Damage was estimated at 1 million dollars September 10, 1933 -A cloudburst occurred ove r the South Platte River between Denver and the foothills with the center over Plum Creek Little Dry and Big Dry C r eek basins Alt h ough information on tributary flows is limited it was estimated that the Plum Creek discharge downstream from the confluence of the East and West branches was about 30,000 cub i c feet per second attenuating to about 5 500 cubic feet per second at the mouth On Cherry Creek a peak value of about 15,000 cubic feet per second was estimate d to have occurred near the mouth while upstream near the site of the Cherry Creek Dam, a peak of 34 ,000 cub i c feet per second was estimated The peak values on Cherry Creek were partially the result of failure of a small dam located i n the upper reaches of the basin On the South Platte at the U.S. G S stream gaging station at Denver, the peak discharge was 22 ,000 cubic feet per second which was t h e largest flood on record prior to the 1965 eve nt (gaging station established in 1895). May 1942-Heavy rains caused e x tensive damages along the South Platte River. The h jgh water destro yed five bridges including those at West Evans and West Mississippi Page 8

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Denver Stonn Drainage Master Plan August 2-3, 1951-Almost J!h inches of rain fell on the Denver Metro area July 9, 1953 Heavy r ains caused estimated 2 million dollars damage from flooded stores and basements across metro Denver. The floodwaters reached a depth of 3 feet on streets in some sections of the City damaging streets and automob il es. The heavy rainfall at Lowry Air Force Base totaled 3. 9 inches July 30-A ugust 3, 1956 Up to 12-inches of rain fell in five days in the Denver area and on the western slope causing $5 million in damage. June 16, 1965 Black Wednesday the day Denver was hit by the worst natural disaster in the City's history After a cloudburst that dw_nped 15 inches of water on mountain slopes southwest of Denver a devastating flood struck 20 cou nti es, inc l uding Den ve r along the Sout h Platte River. Twenty-five people were killed and property damage was estimated at more than $500 mi.Uion. Since that time Chatfield and Bear Creek Dams have been constructed greatly reducin g the flood thr eat to Denver from precipitation over major sub-drainage basins. July 23, 1965Heavy rains in Aurora was h ed out earthe n bridges over Sand Creek Several highways were washed out to t h e east and southeast of Denver. July 24, 1965 Heavy rain fell over all of the Den v er and Aurora areas, causing some flooding of roads streets and bridges. July 7, 1967-A storm caused flood damage in southwest and south Denver. Unofficial report s indicated rainfall of2 inches in 30 minutes and more than 3 inches total from t he stonn. Streets and buildings were flooded by the heavy runoff. Hail in some areas contr ibut ed to flooding b y b l ocking storm drains. Water reached a depth of 5 feet in the street. Police rescued numerous stranded motorists In southwest metro Denver, 100 to 150 homes were flooded and there was one fatality. May 4-12 1969-Heavy rains caused floodin g on the Sout h Platte River in D enver. June 8, 1969 Heav y rain flooded streets and underpasses throughout metro Denver. The hea v iest amounts ofrain fell i n sou th Denver and Englewood w h ere unoftlcial totals of 5 to 6 i nc h es were reported Mud debris and hail carried by t h e hea vy runoff c l ogged drains and in creased the amount of flooding Approximate l y 40 cars and a l arge truck were inundated at an underpass on 1-25, and several more were inunda t ed or burfed i n mud in other areas A large number of basements were flooded a n d streets and hi ghways were hea vily damaged in some areas June 11 1970-O v er 3 inches of heav y rain flooded streets and underpa sses throughout metro Den ver. May 5 -18 1973Prolonged rains of up to 6 inc h es on May 51 h and 61 h in the South Platte Basin, along wit h melting of a l arge snow pack produced major flooding during the next two weeks along Clear Creek Sand Creek and the South Platte River in the Denver metro area One person died and damages were estimated at around 120 million dollars S e pt e mber 2 0 I-I July 20, 1975-Heavy rains caused flash flooding across metro Denver, resulting in the clos in g of several streets and damage to numerous homes and businesses June 13, 1984One of the worst hailstorms ever experienced in metro Denver occurred Torrential rains with as much as 4 75 inches in Lakewood clogged drains and caused widespread damage from flooding Th ere was one fatality. May 16-17, 1995 -S i gn ifi cant moisture and upslope tlow caused flooding across metro Denver Moderate to heavy rains which began on the evening of the 16111 developed in the foothills and spread eastward over metro Denver throughout the night. Aftet the spring floodwaters receded, the Colorado Water Conservation Board (CWCB) and the Colorado Office of Emergency Management reported 15 flood-related deaths statewide and damage estimates approached $20 million June 4, 1995-The heaviest measu r ed rainfall was from a gauge operated by the Pinehurst Go l f and Country C lub l oca t ed in southwest Denver where a reported 3.2 inches fell in less than one hour Residential flooding and storm drainage problems were reported along a small south-bank tributar y to Bear Creek The June 4111 s t onn also caused flood problems in ot h er parts of D enver Englewood and Sheridan This s in g l e thunde r storm produced t h e highest peak flows for the ye ar a l ong l ower Bear Creek and the South Platte Ri v er through Denver July 19 1997-At approximately 4:00p.m., a severe thunderstorm in NE Denver and NW Aurora produced 3 .83 inches of rain in l ess than an hour exceeding the official Denver one-hour record of 2.2 i n ches set o n August 13, 192 1 This storm was acco m panied by copious amounts of hail w ith stone diameters reachin g 1 .25 inches. Westerly Creek, a tributary to Sand Creek th at enters the old Stap leton Internationa l Airport property from the south flowed out of its banks and nearly overtopped Montview Boulevard The Mon tview culverts are designed to safely pass a 1 0-year flood a project completed by Denver Aurora a nd UDFCD in 1980 July 27, 1997-Between 3:00 and 4 :00p.m., Goldsmith Gulch in Den ve r was hit by heavy rains with 1.66 inches falllng at the Denver Tech Cente r ( DTC) Downst re am floodwaters approached 1 0-year l eve l s causing the recently comple t ed s ide-channel detent i on facility n ear lliff Avenue to fu n ction. This flood control facility construc t ed by Den ver and UDFCD in 1996 was credited with preventing damages downstream Local residents were p l eased with its performance A minor g lit ch did occur however when the pump that drains the facility failed to start Denver Wastewater Management Division officials corrected the problem the next day. The Eastman Avenue ALERT gage peaked at 4 p.m. at a depth of7.4 feet with an est im ated discharge of 1 670 cfs exceeding its prior recor d of 1 470 cfs (8/2/91) The Temp l e Pond gage at the DTC had a ma x imum water depth of 8 2 feet and a peak outflow of 470 cfs Page 9

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Denver Stonn Drainag e Master Plan llif(Stormwater Detention Basin on Golds mith Gulch July 28, 1997Some significant flooding occurred 1n Denver witb Goldsmith Gulch being hit hard for the second consecutive day, exceeding the prior day s peak at Eastman Avenue by one foot and setting a ne w record of2, 040 cfs at 6 :30p.m. Upstream at Temple Pond Goldsmith floodwaters pooled to a depth of9, 5 feet releasing 500 cfs Dow nstream of Eastman at Yale Avenue the peak flow was estimated at 1 850 cfs and classified as a 10-year event. According to the Goldsmith Gulch design h ydro logy model the discharge at Eastman approached the 50-year mark. As with the previo us day's storm, the Iliff detention facility and impro ved channel reache s performed as designed preventing significant dama ges. B y 9:00 p m Gol dsmith Gu lc h floodwaters had combined with Cherry Creek flows causing the Market Street gage in lower downtown Denver to measure its new record peak of 3,200 cfs The Cherry Creek gage at Steele Street al so set a new record at 2 ,350 cfs. Heavy rains in other parts of Denver and Aurora caused localized floodin g of many roads parking l ots and basements -Goldsmith Gulch downstream of Yale Avenue on July 28, 1997. July 29, 1997 Late evening rainfall on Ju ly 28 caused the Sand Creek ALERT gage to measure a new record tlow of 4 200 cfs at 2:47a. m (see Jul y 19 discussion ). At Sand Creek Park near its crossing with 1-225 the pedestrian trail cross ing was overtopped b y 4.4 feet and the discharge was September 2014 estimated at 3,480 cfs another ALERT gage record A parking lot flooded at Quebec Street and Leetsdale Drive in Denver to the point that a car was found floating in it. August 11, 1997-Hail depths of up to 2 teet, d r iving rains and high winds caused an estimated $150-million in damage in Lakewood and Denver. A rainfall amount of 1 inch in 10-minutes was measured b y the Cherry Creek gage in downtown Denver and after the hail melted the total measured precipitation exceeded 2 inches. Cherry Creek flowed wall-to-wall at a depth of approximately 5 feet with a peak discharge of2, 640 cfs. This was the second highest measurement for Cherry Creek for the year, exceeded on l y by the July 28 event. September 4 1997Cherry Creek flowed wall-to-wall. Five rain gages had alarmed (1 jnch in less than 1-hour) by 9 :45p. m The l ocations and amounts were accurately reported to the public at the start of the 10 p m broadcast July 25, 1998 -Heavy rains that occurred during the evening caused problems i n Denver with flooded basements, stranded drivers and d owne d power Unes A forecaster for the NWS measured 3 inches in 30 minutes at his home near W 38th Avenue and Federal Boulevard The railroad viaduct near 38th and Fox (Basin 0061-01) trapped motorist s in water 4 to 5 feet deep This notorious flood area has been less of a problem in recent years due to drainage improvements comp l eted by Denver and UDFCD but this storm clearly exceeded the design rainfall amounts. July 30, 1998 Den ver streets flooded, zodiac boats were needed for rescues at ''Lake Logan (Logan Street underpass of l25) and a kayaker was rescued from the South P latte at Santa Fe July 31, 1998-A flash flood watch was issued by the NWS shortly after 2 p .m for the entire Front Ran ge from Colorado Springs to Fort Collins. ln Den ver, street floodin g damaged pri vate propert y in the v icini ty of Evans Avenue and Lipan Street. April29-May 1, 1999On April 30 and May 1 the NWS issued flood watches for the South Platte River and other la rge Denver area streams. Gradual rise s in rive r stage w ere observed due to relati v ely high rainfall accumulations ove r the prior week. Englewood Dam recorded a record hig h water depth of 1 6 2 feet on April 3 0 Spillway flows begin at a depth of 40 feet. Flood control improvem e nts to this District-owned normall y dry detention dam were completed in 1 976 July 31 1999 -Martin Luther King Boule vard in the Park Hill area of Den ve r was barricaded due to flooding between Colorado Boulevard and Quebe c Street. However this measure did not sto p s i x motorists from driving into tbe flooded area and stailjng. Sand Creek rec orded its annual peak while the Havana Park detention facility in the Westerly Creek basin overflowed into neighborhood streets. Thunderstorm rain in Den ver and Aurora exceeded one in c h at 8 gaging stations with 1 69 inches occurring at Horseshoe Park in Aurora August 10, 1999-In the Denver area more than 3 inches were reported to have fallen in less than an hour The highest ALERT rain measurement was 2.52 inches near I-225 and Sand Creek in Aurora In a ddition to the wind and rain hail and lightning cau se d problems for man y areas including DIA. P age 10

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Denver Storm Drainag e Master Plan August 17, 2000-Denver Fire Fighter Bob Crwnp died in the line of duty after rescuing a woman from floodwaters in the vicin i ty ofE. 49th Avenue and Colorado Boulevard (Basin 0060-01). Mr. Crump l ost his life after being pulled into a submerged open 36 inches stormdrain The storm at thjs location was estimated to be a 75-year event. The flooding that was realized this day was somewhat unexpected. Morning analysis indicated minimum flood potential but weather conditions changed substantial l y by mid-afternoon Within 10 to 15 minutes heavy rainfall was occurring over no11hem Douglas County and the Littleton area By 4 p.m. the NWS had issued an u rban and small stream flood advisory for this storm and at 4:37p. m the advisory was upgraded to a flash flood warning for a large portion of the Denver metropolitan area May 3-5,2001 -Three da ys of steady ups l ope rain saturated soils along the Front Range RainfaJI amow1ts totaJed 2 to 3 inches over much ofDenver causing some minor street flooding while larger streams like Cherry Creek and the South Platte River rose above normal. Two reservoirs monitored by the ALERT system recorded their annual peaks on May 5. June 20,2001-At 7 :20p. m., heavy rain and damaging hail struck DIA causing major damage Between 40 and 50 mobile homes were a l so damaged in the Watkins area. July 8 2001 -Serious street and stream flooding hit Den v er between 4 and 6 p m The storms were accompanied by high winds and small hail. Flash flooding was observed on Harvard Gulch Goldsmith Gulch Cherry Creek, the South Platte River, and along 1-25 where the infamous "Lake Logan" (Logan Street/I-25 underpass) once again stopped traffic The Harvard Gulch at Jackson Street rain gage measured the heaviest rainfall of 0.67 inches in 5 minutes and 2.48 in ches in an hour Goldsmith Gu l ch upstream of Mexico Avenue o n July 8, 2001. July 23, 2001 -A highl y l ocalized storm impacted rush hour traffic around the Denve r Tech Center. Hail wind and rainfaJl amounts exceeding 1.2 inches in 30 minute s slowed travel on I-25 and I-225 Funnel clouds were also reported The South Platte River gage at Union Avenue recorded its record flo w for the y ear. September 2014 August 5, 2002-A heavy thunderstorm near DIA set a record high water level for the 2-year-old ALERT stream gage on Third Creek. The rain gage at that station measured 2 361nches and prompted the NWS to issue a flash flood warning Most of the metro area received less than an inch of rain while two gages in the Bear Creek basin measured over an inch. September 13, 2002 Once again the I-25/Logan Street underpass was inundated by stormwater this time disrupting traffic for over 3 hours during evening rush hour. A number of motorists were rescued from their vehicles. Rainfall totals L06 inches to L 18 inches were measured near the I-25 corridor between the Denver Tech Center and Broadway The Transportation Expansion Project (TREX) construction vast ly improved this histotic drainage problem. August 18, 2004-It was a deluge that produced standing water across the entire region and an average of 1.62 inches of precipita t ion fell on Denver. The South Platte River swelled to 10 000 cfs from 300 cfs earlier in the day The Denver Fire Department responded to nearly 180 calls between 4:30 and 6:30pm, 10 t i mes the normal volume. Man y of those caJl s requested water rescues City and State crews used snowplows to clear water from clogged drains in Denver. About 5 inches fell on the Denver Zoo. A car was swept over a 6-foot embankment about 1:00 am. Two l anes of northbound 1-25 at West Alameda Avenue we r e closed under 8 inches of standing water. The worst flooding spots were : 1-25 at Alameda and 1-70 in the area of Vasquez Steele and York streets, Manna Pro grain elevators at 44111 and Madison and the Union Pacific Railroad bed was washed out at the BNSF cross.ing bet wee n Madison and Monroe Streets leaving 100 of track hanging in midai c June 3 2005 -A hea vy thunderstorm swept through southeast Den ve r flooding 9 homes in the Hamden Heights neighborhood to varying degrees as well as flooding East Girard west of Havana damaging numerous parked cars This storm was estimated to be between a 50 and 1 00-year rainfall event. Surcharging on storm drain manholes in Five Points was recorded. Flooding onE Eas tman Avenu e on June 3 2005. P age 11

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D enve r Storm Drainage Master Pla n July 4, 2006 Independence Day was a weather-producer in 2006 with nature contributing its own fireworks. Denver and Arvada were the primary targets for hea vy rainfall with many gages reporting more than an inch of rain. The C h erry Creek gage a t Steele Street me asured the greatest amount of 1.7 3 inches. The rainfall did not howe ver prevent the anticipated celebrations from taking place Five stream gages recorded annual August 13, 2006 Multiple storms occurred during the evening hours causing the ALERT system to ge nera te 11 rainfall alarms from 7 stations in Denve r Aurora and Golden between 8:15 and I 0 : 40 pm. Annual peaks occ urred at 8 st ream gages on Harvard Gulch, Goldsmith Gulch Westerly Creek and the South Platte RiveL This was a busy day for the ALERT system but fortunately no major damages were reported-just some nuisance flooding during the late evening. Consequently, this event attracted little media attention August 14,2006 Hea vy rainfall was recorded in the Capitol H ili area, causing flooding on East Colfax at Clarkson Wimams and Colorado Boulevard Busine sses and subterranean condominiums along 1 t11 Avenue from Lafayette to Humboldt were also flooded. A u gust 19, 2006 Nort hwe st Den ver experienced an intense local ized s t orm ce ll resulting in flooding at theW. 381b Avenue underpa ss of the ra ilr oad tracks between Inca and Fox. May 14,2007A thunderstorm developed rapidly due to multip le thunderstorm ou tfl ow boundaries that were initiated by weak and moderate thunderstorms across western Jeffer so n a nd western B o ulder Counties. The thunder storm produ ced heavy rainfall of0. 75-inch to 1.50-inch in 10-30 minutes ac ro ss eastern Jefferson, Den ver western Arapahoe and southwest Adams Counties Short lead Red Flood Alerts we r e i ss ued for these 4 counties. T wo-year-o ld Jose Matthew Jauregui Jr. was swept away by rapidl y rising water along a bike path in Lakewood Gulch at Decatur Street. His body was later recovered downstream in the South Platte River. Flooding in southern Denver on July 27, 2007. (Photo C ourte s y Denv e r Post) July 27, 2007 -A Flash Flood Watch was issued for the entire Denver area due to the thr eat of very h eavy rainfall that could initiate flash flooding a nd urban flo o din g Stro n g thunderstom1s developed late i n th e afternoon across the sou thern port ion of Den ver. The storms mo ved very slow l y to the September 2014 north producing hea vy rainfall of 1 50-inches to 2.50-inches in 30-60 minutes prompting a Flash Flood Warning for Den ver Arapahoe and Adams Cou nties. August 8, 2008 -A severe thunder sto rm cell moved through central, east centra l and sout hea st Denver causi ng flooding in the Country Club neighborhood, Cherry Creek North, Hale Parkwa y Severn Place between Jer sey and Jasmine S Holly and Pacific Place and E. Mississippi and Leetsdale / P arker R oad. In some areas 2-inch to 2 5-inch of rain was recorded in a 1 hour p eriod equivalent to a 100-year storm Several homes, business and apartments were flooded in each of these areas April16 18 2009 A big precipitation event arrived by way of a winter sto rm. Many strea m s we re flowin g well above normal and fou r stormwater detention basins recorded a nnual peak s includin g Kelly R oad Dam in D e n veL Den ver Fire Departm ent rescued at least o n e person that became trapped between the c hannel walls of Cherry Creek. May 24 25, 2009H eavy intense rain dropped 2-inch pl us rains over central Den ve r Minor flo oding occ urred alo n g Lakewood Gulch thro ugh Den ver w ith a peak flow of 600 cfs at 1Oth Avenue June 23-25,2009 This sto rm impacted DIA and caused street floodi ng durin g rus h h o ur wit h hail that hit the northwest metro area. Thes e storms produced stron g east m ov in g th under s torm s over D enver t hat ca u sed a downpour of 1.5 to 2.4 inche s in 20-45 minutes and prompted a NWS flash flood warning in thjs 3-day period. Four eas t Den ve r condominiums we r e flooded by 4 feet o f water and a dog die d at 5300 East C herry Creek Dri ve South Seve ral home s flooded along East Missouri Avenue and the sump at East Tenne ssee Avenue and Oneida Street flo o ded R a infall tota l s excee ded 2 in ches at so me locati ons July 3 2009This day was the secon d in a 5-day series of stormy days. The Natio nal Weather Service repo rte d that severe thunderstorms produced lar ge hail n orth and eas t of Den ver. Local i zed flo oding was reported in centra l and so utheas t D enver including S. Glencoe so uth ofE Yale Avenue Flooding on Harvard Gulch on July 3 2009. (Photo Cour/esy Ed Done) Pag e 12

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Denver Stonn Drainag e Master Plan July 10 2009Storms triggered many rainfall rate alarms between 8:30 and 10 p.m. in Denver causing some minor street flooding and flooded severa l properties in central and east Denver. July 20, 2009-A supercell thunderstorm moved quickly to the south producing very intense rainfall large hail and powerful straight line winds Property damages from the wind and hail were high and localiz ed flooding was reported in east Den v er. The storm duration was short but the rainfall intensities were ve ry high April 21-23, 2010 -A system of strong thunderstonns produced large hail and heavy rainfall The stormy period la sted about 48 hours changing over to a w i despread rain and snow storm w ith precipitation totals exceeding 2 inche s at many locations. Runoff from the storms caused annual flood peaks affecting Kelly Road Dam on Westerly Creek in Denver and Sand Creek and Chen-y Creek through Denver. No serious damages occurred; however this storm caused the largest widespread flooding event of the 20 I 0 flood season. August 4, 2010Heavy rains impacted Westerly Creek in Denver. Annual flood peaks were recorded in this drainage basin. While rainfall totals only approached 1.4 inches in this area stations measured very high intensities July 7, 2011-This was the biggest rain day of20ll. Rainstorms appeared with flash flood and severe thunderstorm warnings being issued for Denver County. The heaviest total rainfa ll occurred in the area bounded between Alameda A v enue and l-70 from I-25 on the west to I-225 on the east. The lar gest storm totals exceeded 3 inches in the Westerly Creek basin l ocated in Denver. Denver officials reported that storm sewer manholes popped their covers at over 50 locations. Numerous streets, intersections and underpa sses were flooded, and dozens of properties reported flood damage across a w ide swath in central and east Denver Fenil Lake as City Park which had been modified in 2007-2008 to provide stormwater detention rose nearl y 3 feet during the storm as intended Annual peak flows were recorded for Westerly Creek in Denver S.O ( 1.S) .,,o (l4) 20 0)) 1,5 un J..tl {<>.l.) 0.9 (10\ 0.8 0 7 (8) 0 6 t.,) 0" ( 0 ) o ... (S} {"') o,::: (;J) 0.1. (:f) u o U) Tota l Rainfall o n July 7, 2011. Red Shades Indicate 2-and 3-lnches of Total Precipitation. ( C ourtesy of NOAA) September 2014 July 12, 2011 -Annual peaks were measured in Denver on Cherry Creek Lakewood Gulch Sanderson Gulch and the South Platte River. The Sanderson Gulch and Lakewood Gulch stream gages set new records Rain totals were mostly l ess than 2 inches JuJy 13, 2011Storms caused an annual streamflow peak on Goldsmith Gulch in Denver. Damage was reported at the Boys and Girls Club in Denver s Westwood neighborhood and flo oding was reported at one home in west Den v er. July 14, 2011 -Heavy rainfall occurred to the west in Denver County where annual peaks were recorded for Harvard Gulch and Goldsmith Gulch at Iliff Avenue in Denver. Flooding was reported again in Glencoe Street south of Yale Ave nue JuJy 7, 2012-A late evening storm arrived the evening before and remained until the morning of July 7 affecting Denver County September 12,2012Denver was issued a special Cben-y Creek Trail Flood Advisory for lo w impact flooding due to a general wide-spread l ow-intensity rainfall over the region July 13,2013 -Multiple thunderstorms moved through Den v er during afternoon hour s w ith rainfall totals exceeding 3 inches. The storm caused Lakewood Gulch in Den ver to rise over 6 feet in a short period setting a new record for the USGS gage that has operated continuousl y since 1981. Localized flooding was reported at Martin Luther King Boule v ard and Eudora Street. September 9-15 ,2013Waves of rainfall during mid-September caused significant flooding and related damage outside ofDenver, especially in Aurora Commerce City Boulder Jamestown, L y ons and Estes Park. Denver experienced sign ific ant rainfall and peak flows Rainfall inten sities exceeded 3 inches per ho u r for periods of time on September 9 10 1 2 and 15. Overall total precipitation e x ceeded 1 2 inches in some parts of Denver. More than 5 inches fell over the Westerly Creek basin and activated the spillway at Kelly Road Dam atE 11th Avenue & S Willow Street. Floodwaters on Sand Creek caused considerable bank erosion that threatened the Metro Wastewa t er Treatmen t Plant near its conflue n ce with the South Platte River. 1..!-ast Denver F loodin g on Septembe r 12, 2 013 (Photo Courtes y Tony Ryan) P age 13

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Denver Stonn Drainag e Master Plan 1.4.5 Existiltg Cmulitions The associated Technical Appendix notebooks are organized by basin and include all CUHP and SWMM hydrologic and FL0-20 models Existing drainage conditions have been evaluated through field reconnaissance, research of complaint records and detailed hydrologic modeling using the Colorado Urban Hydrograph Procedure (CUHP 2000) and Urban DraiJ1age Storm water Management Model (UD-SWMM) software developed by UDFCD Modeling of the fully urbanized basins within the City and County of Den ver poses a significant challenge because of the high degree of impervious area and complex basin routing inherent in the system To ensure that a reasonable model was developed to simulate these conditions there has been extensive coordination among the consultant team City and County of Denver staff and UDFCD. The participation of this. team of experts has resulted in the development of sophisticated models which are linked with GIS based capital budgeting tools This approach will enable the models to be incorporated in subsequent versions ofCUHP and UDSWM, including tbe incorporation of future GIS advancements Parameters for Stormwater Runoff Volume 1 of the UDFCD Storm Drainage Criteria Manual provides the basis for input data for CUHP. fu order to more accurately simulate tbe potential for runoff under future conditions, the Den ver GIS database has been used to evaluate existing land uses and densities w ithjn commercial and residential areas. These have been compared with the permitted densities (and corresponding imperviousness) for c urrent zoning and have been overlain with Blueprint Denver to ensure that a reasonable upper limit i s used Generally the imperviousnes s for resid ential areas was set at 52%, commercial/retail from 80 to 90% and industrial 90 to 95%. One-hour rainfall depths for the CUHP model were obtained from the Urban Storm Drainage Criteria Manual Volume 1 for the foJlowing recurrence 2-year 0.95 inches 5-year 1.34 inches 1 00-year 2 57 inches Evaluatio1t o(Sp/it Flow Conditimu H yd rologic modeling of drainage conditions within Denver i s further complicated by split flo w conditions in major storm events whereby the direction of stonn drains contrave nes the surface gradient. Many of the existing storm drain systems ha ve little more than 1-year capacity, and will ha ve 2 to 5-year capacity under proposed improvement conditions Delineation of the basin s is important to ensure proper sizing of proposed impro ve ment s and also to evaluate overland flood flow conditions As a res ult, two models have been developed : 1) a low flow model for the minor storm event and 2) a split flow model whjch extracts the low flow and accounts for trans-basin diversions of flow to enable mapping of potential hazard areas under 1 00-year storm event conditions Potential inundation areas are shown as s haded zones on the full-size work map s (see Technical Appendices or GIS database) to facilitate planning staff review of development applications and to advise potential landowners or developers of inherent localized flood hazards These are areas where pendin g or flow depths could exceed 18-inch ; however they have not been mapped using regulatory criteria or modeling technique s and are therefore considered only a rough guide of potential inundation September 2 0 1-J 1.4. 6 Future Dm,elopment The Denver Storm Drainage Master Plan is one of several documents that will feed information into the City's Comprehensive Plan Blueprint Denver is. another essential framework doc u ment that both identifies major transportation network improvements and establishes the basis for future land u se planning. To assist w ith future planning, "Areas of Change and Areas of Stability h ave been delineated in Blueprint Dem,er The Areas of Change map is included for reference to show the potential for changing hydrology and highligh t the areas where capi tal investmen t in infrastructure i s expected 2.0 MAJOR DRAJNAGEWA YS The following is a description of each of the major drainageways within the City and County of Denver beginning furthest downstream and continuing upstream 2.1 South Platte River (Basin 0000) The South Platte River i s the largest receiving waterway in the Denver Metropolitan area and flows from south to north along the I25 corridor through the City and County of Den ver. Within the City limit s of Den ver the South Platte River meanders along a path some 11.7 miles in length from Dartmouth Avenue to Franklin Street The drainage bas .in covers approximately 4 850 square mile s e x tending from the Continental Divide in the Rocky Mountain Front Range to the hig h plain s and foothills of eas tern Colorado The mountainous portion of this basin is generally unsuited for dense development w hile the foothills and high plains areas are actively being developed The intense urbanization in the metropolitan area consists primarily ofresidential and commercial areas and some indu stria l reg ions along the river va lle y The South Pl atte River t1ood potential is mitigated by Chatfield Reservoir (co nstructed in 197 3) loc ate d on the South Platte Ri ver along w ith Cherry Creek Reservo ir (constructed 1950) and Bear Creek Reservoir (constructed 1977) located on major tributaries. S hort duration flooding wiU continue to occur from extremely heavy precipitation in those areas belo w the dam-site s Peak 100yea r flows of the South Platte vary from 5 000 cfs near Chatfield to 38 000 cfs at the confluence with Sand Creek. Dry weather di scharges in the South Platte Ri ver through Denver generally range from 150 cfs upward to over 1,000 cfs during the spring runoff period. Average daily flows downstream of Den ver are highl y affected by treated effluent discharges from the Metro Wastewater Reclamation Distric t treatment plan t 2.2 Second Creek (Basin 3500) Second C reek drains about 27 s quare miles of area to the South Platte Ri ver. The basin is abo ut 15 miles long and 3.4 miles wide at its widest point The drainage basin ranges in elevation from 4 990 at the South Pl atte River to 5,650 feet at the basin div ide Second Creek has a natural irre gu lar channel section in the upper reaches above the O Bri an Canal. The Second Creek Basin is crossed by US Hwy 85 U-76, tbe Union Pacific and Burlington Northern Railroads the O Brian Canal Fulton Ditch and the Burlington Dit c h Second Creek has a natural irregular channel section above the O Brian Canal and a small poorly defined channel section between the O Brian Canal and the Page 14

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Denver Storm Drainag e Master Plan South Platte River. Existing development within the Second Creek basin is mainly agriculturaL with irrigated fannland located in the South Platte River Valley and dryland fam1ing and pasture in the upstream areas. The southern land area of the Second Creek drainage basin within the Denver city limits drains via a tributary known as the West Fork of Second Creek. This tributary drains about 3 square miles of area to Second Creek. The High Line Canal terminates at the West Fork. The sustained unused flow in th e High Line Canal has been wasted to the West Fork downstream of 64th Avenue and the flows have eroded the channel on the West Fork. At Tower Road the West Fork channel is about 15 feet deep with vertical and very steep unstable banks. Th e confluence of Second Creek and th e West Fork of Second Creek i s a wide, relatively flat area supporting a sta nd of cottonwood trees Some wetland areas are present in the upper reaches of the Wes t Fork, bu t, as t h e channel has eroded the channe l banks have become incised and support onl y a narrowband of wetland or riparian vegetation. The floodplain is contained within the channe l e xcept at road crossings, where overtopping may occur. The bank s are unstable and some lateral channel migration may occur during l arge flows 2.3 First Creek (Basin 3700) The First Creek basin drains an area of 47.2 square m i les. The headwater s of Fir st Creek are located in Arapahoe County south of I70 and east of E-4 70 Runoff from the basin flow s in a northwesterly direction First Creek crosses Pefia Boulevard just north of 56th Avenue and flows th r ough the northeastern port i on of the Rock)' Mountain Arse n al. First Creek is an east bank tributary to the South Platte River and outfalls at approximate l y 1 281 Avenue. The basin shape is l ong and narrow approxima t ely 26 miles long and 2 to 4 miles wide. The average stream slope above Rocky Mountain Arsenal is about 3 1 feet per mile and flattens to about 23 fe e t per mil e below Rocky Mountain Arsenal The u pp er reaches of First Creek are primaril y unde velo ped irrigated cro pland wit h wide swa l es and c h annels for drainageways Toward the center of the basin, First Creek bisects Green Valley Ranch wh ich co n s i sts of medium density s ingle-family residences. First Creek then enters Rocky Mountain Arsenal with a more incised low flow channe l and w ider floodplain areas. T h e l ower First Creek basin i s located down s tream from 561b Avenue and Pefia Boule var d and continues to the South Platte River. The lower First Creek basin consists of irrigated fam1land with pockets oflight industrial and residential properties Conveyance within the lower First Creek drainage consists of broad undefined channe l s with l itt l e o r no defined thalweg B etween US-85 and Brighton Boulevard the channel i s incised w ith a well-defined thalweg. The O Brian Cana l and the Burlington Dit c h which i n tercept runoff in First Creek cross t h e reach of First Creek below Rocky Mountain Arsenal 2.4 Irondale G ulch (Basin 3900) Irondale Gu l ch w hich contains approximately 26.7 square mile s lies immediately southwest of First Creek and drains t he general area near the intersection of 1-70 and Pi cad illy Road and th e September 20 I./ Adams County line through the Montbello area, the Arsenal and Commerce City with an eventual outfall to the South Platte River at approximate l y East 961b Avenue The southwest boundary of the basin is primarily the north side of l-70 until reaching the former Stap l eton International Airport, w h ere the basin boundary lies just west of H avana Street. This bas in is long and narrow, with a total length of 28 miles to the South Platte River and l Y2 to 2 miles wide. The average slope of the basin is about 26 feet per mile, which remains fa irl y constant throughout the drainageway The drainageways throug h the Arsenal conta in several lakes and detention areas. The drainage below t h e Arsena l is primarily storm drains or roadside ditches with capacity for only m.inor floods 2.5 Clear Creek (Basin 4300) Clear Creek i s a west ban k tributary to the SoutJ1 Platte R i ver and h as its so urce in the Rock y Mountains west of Denver Flowing in a ge nerally easterly direction from the Continental Di v i de Clear Creek enters the high plains in Golden Within this l ower reach, Clear Creek passes through unincorpora t ed areas of Adams and Jefferson Counties and the cities of Golden Wheatridge Arvada and D enver Clear Creek crosses the nort h west comer of D enver for a distance of0.2 miles in the v icinity of 52d Avenue and Gray Street. The drainage area at the mouth is 575 square miles of w hi c h 400 square mile s are in the mountain region a b ove Golden There are 11 major reservoirs in the lower Clear Creek basin t hree of which are on-stream and provide some res i dual flood control effects downstream from each site Ralston Resetvoir was built in 1938 by Denver and recei ves water from Ralston and South Boulder Creeks Although Ralston R eservoir is not operated for flood control purposes, there are approximate l y 2,400 acre-feet of storage avai l able Maple Grove Reservoir i s located on Lena Gu l ch at West 27 th Avenue and h as appro x imately 452 acre-feet of avai l able storage. Leyden Lake is an irrigation water storage reservoir on Leyden Creek upstream from Indiana Street and has approximate l y 550 acre-feet ofuncontrolled storage 2 .6 Sand C r e ek (Basin 4400) Sand Creek i s an east bank plains tributary of the South Platte River. The Sand Creek basin lies in north-central Colorado to the east and northeast of Denver' s Central Business Distric t. The Sand Creek basin encompasses an area of 189 square mil es. The basin is long and narrow, w ith a l ength of 32 miles and an average w idt h of 6 miles Portions of Elbert D ouglas Arapahoe Den ver and Adams CowJties are included in the drainage area Sand Creek originates at the confl uence of Coal Creek and Murph y C r eek Sand Creek joins the Sout h Platte River in the v icinity of I -270 in Commerce City, not 1h of Denve r city limits. The reach of Sand Creek within Denver is located alo n g I -70 near the Stap l eton Redevelopment area Principle tributar i es of Sand Creek are Toll Gate Creek and Westerl y Creek 2.7 Westerly Creek (Basin 4401) The Westerly Creek tributary area consists of approx i mately 18 square miles of highl y developed area from the low ro llin g d i v i de between Cherry Creek and West Toll Gate Creek to the conflue n ce Page 15

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Denver Storm Drainage Master Plan with Sand Creek. The basin is about 8.5 miles long, 3 miles wide at its widest point. The crescent shaped area drains in a northwest-to-north direction with an average slope of 0.9 percent. Development in the Westerly Creek drainage basin is at a state of full development consisting of townhouses condominiums apartments, single family homes, motels large shopping complexes streets parking areas and highwa ys This development and the basin slope contribute to t he rapid response time for storm runoff and increased storm water runoff. The upper reaches of Westerly Creek begin in the City of Aurora Runoff of peak events is captured in Westerly Creek Dam, built in 1989 on the former Lowry Air Force Base at Alameda and Havana. Westerly Creek fully contains the 500-year flood event and outlets via a 48-inch pipe. Flows from the Lowry Redevelopment area enter Westerly Creek and then are detained in Kelly Road Dam at 11 tb Avenue. The channel and culverts from Kelly Road Dam to Montview at the Stapleton Redevelopment area have been improved to the 10-year storm design The Westerly Creek channel through the Stapleton site has been improved to 100-year capacity. All storm outfalls to Westerly Creek within the Stapleton site have regional water quality treatment at the end of pipe. 2.8 Montclair (Basin 4500) The Montclair Drainage basin consists of approximately 9.44 square miles (6 040 acres) and is the largest storm drainage basin in Denver which does not have a surface drainageway A survey in 1861 shows two watercourses converging at present-day East Colfax and Colorado Bou l evard then continuing north west through present-day City Park (Ferril Lake) and onward to the South Platte Ri ver. A 1979 Geologic Map ofDenver, prepared by the USGS shows an identical pattern of alluvial soils as depicted in Figure 2. The Capitol Hill Storm District Number 1 created in the early 1900's financed construction of a large storm drain following this draina geway to convey storm flows to the South Platte River. In larger storms, runoff in excess of the drain capacity follows the original drainageway path and causes flooding at numerous locations and intersections 2.9 Cherry C r eek (Bas i n 4600) The Cherry Creek tributary area consists of 410 square miles of which 385 square miles drain into Cherry Creek Reservoir. The dam is designed to release a maximum of 300 cfs during the 1 00-year event and 5,000 cfs in the Probable Maximum Reservoir Release (P.MF) to the lo we r Cherry Creek channel, wh ich has a current capacity ofbetween 4 000 and 11, 000 cfs The lower Cherry Creek basin covers 25 2 sq uare mile s w ith Goldsmith Gulch contributing 7 7 square miles of the total area. The lower channel of Cherry Creek flows 11.5 mile s from the reservoir to the South Platte River confluence in the vicinity of Speer Boulevard The lower channel has been improved to contain the 1 00-year storm from 15 1 Avenue to the confluence These improvements generally consist of cleaning, shaping, and landscaping the channel bottom. September 2014 :. f-t... : I I >slS -' l I I to-..... IC l "V ....... r X '1 B ,. J ri-o t, rc t I : .. Figure 2: USGS Geologic Map of Den ver (1979) showing alluvial soils pattern in yellow. 2 10 Goldsmith Gulch (Basin 460 1 ) I 11 "l I I I l < The Goldsmith Gulch basin encompasses an area of7.8 square miles from Arapahoe Road northwest to the confluence with Cherry Creek. Through Den ver, the tributary area is primaril y urbanized or in t he process of de velo pment from a mi x of commercial and residential construction. Many channel impro v ements have been completed along Goldsmith Gulch to reduce the potential of flood damage. The channel has been stabilized and regional parks have been constructed in the floodplain Detention facilities hav e also been constructed along the channel at Bible Park, Wallace Park, Rosamond Park and at Diff and Monaco. Channel slopes are generally mild wit h several newer drop structures along the re ac h The High Line Canal bisects Goldsm i th Gulch at East Cornell Avenue. Goldsmith Gulch passes underneath the High Line Canal and East Cornell Avenue t hrough a concrete box culvert. The upper portion of Goldsmith Gulch includes the recent I-25 TREX construction site. New storm and detention facilities drain the I-225 and 1-25 interchange to Goldsmith GuJch Page 16

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Denver Stonn Drainag e Master Plan 2.11 Sloan's Lake (Basin 4700) The Sloan's Lake drainage basin flows eastward from a high point near 261 h Avenue and Garrison Street in Lakewood and outfalls into the South Platte River near Colfax Avenue and Iuvesco Field The drainage basin lies within Denver s jurisdiction east of Sheridan Boulevard and is bounded by West 32ud Avenue on the north Colfax Avenue on the south, Garrison Street on the west and t h e South Platte River on the east The basin totals almost 5.5 square miles within Denver Lakewood Edgewater and Wheatridge. Since the basin is fully developed and heavily urbanized, the major drainageways are not clearly identifiable Most of the hjstoric drainage channe l s have either been filled in or built over to the point of obliteration The most prominent geographic feature withi n the bas in is S l oan s Lake The l ake, which occupies 176 5 acres of a 290-acre Denver park, has been and continues to be a valuable recreational resource for the metropo l itan area In addition to its scenic and r ecreational significance the lake provides the important function of regulating and controlling downstream flows that otherwise would. be allowed to run uninhibited through West Denver The l ake r educes peak flow rates from about 2 904 cfs to 166 cfs during the 100-year event. 2.12 Lakewood Gulch (Basin 4800) Lakewood Gulch is a major dralnageway that originates in Lakewood and flows easterlyr toward the South Platte Rive r between 61h Avenue and Colfax Avenue The Lakewood Gulch basin consists of approximate l y 16 square miles beginning i n the foothill s and extending easterly 10 mil es to t h e Sout h Platte River in the vici nit y of Co l fax Avenue. The tributary area is essentially fully developed in Denver and in the eastern portion of Lakewood. The basin is also developed in the westem port i on of Lakewood and. Jefferson Cou n ty 2.13 Ory Gulch (Basin 4801) The Dry Gulch bas in consi sts of approximately 3. 7 square miles l ying p r edominant l y i n Lakewood Dry Gulch is tributary to Lakewood Gulch in the vicinity of 10 th Avenue and Perr y Street in Denver and extends westward a length of 5,7 miles along the general alignment of Colfax Avenue to Simms Street. The basin is essentially fully developed with commercial establishments along Colfax Avenue a n d residential development comprising the remainder of the basin 2.14 Weir Gulch (Basin 4900) Weir Gulch meanders eastward from Green Mountain for approx i mately 8.3 m i les to the confluence with the South Platte River in the vicinity of West 9th Avenue. The 7.2 square mile drai n age basin is fully urbanized in Denver and mostly develo ped west of Sheridan Boulevard in Lakewood. Much of Weir Gulch is lackjng natural stream charac ter and riparian vegetatioh Many sections of the gulch are underground in a concrete box culvert or open on the top in a 3-side d conc r ete box. There are two defined major drainageways tributary to Weir Gul ch within the City and County of D enver. Th e l '1 Avenue Tributary to Weir Gulch is located just north of 151 Avenue and flow s in an September 20 easterly directio n The dra i nage basin is bounded by 6th Avenue on the nmth West Alameda Avenue on the south Raleigh Street on the east and Wadsworth Boulevard. on the west Th is tributary of the Weir Gulch system is approximately 2 miles l ong and about 0 8 mile wide with an average slope of 1. 5 percent. The Dakota Avenue Tributary to Weir Gulch li es within Den ve r s jurisdiction east of S h eridan Boulevard and is located just south of Dakota Avenue flowing in an easterly direction I t is bounded by West Alameda A venue on the north, West Alaska Avenue on the so uth Sheridan Boulevard on the west, and Xavier Street on the east. This tributary is about '14-miles wide and has an average s l ope of 1 Strip parks have been developed by the Denver Parks and Recrea tio n Department from 18 1 Avenue to Alameda Avenue along the gulch. This de ve lopment consists mainly of w-assed channels and the illstallation of asphalt bike paths Barnum Park is located on both sides of 6111 Avenue on the west side of Federal Boule vard. Barnum Lake located south of 6th Avenue has been improved to contain the 1 00-year storm within the Weir Gu l ch channe l The open park area n orth of 6111 known as the Federal Boul evard Detention Reservoir is des i gned to reduce the 25-year flow to a l 0-year flow or less The lower Weir Gulch channel from Federal to the Sou t h Platte River outfall ha s capacity for the 1 0-year storm. 2.15 Saudenon Gulch (Basin 5100) Sanderson Gulch flows 8.63 miles i n an easterly d i rection from South Union Boulevard above Smith Reser vo ir to the South Platte River in the v i cinity of West Florida Avenue. This drainage basin which encompasses a p proximately 9 square miles is fully developed in Denve r and is being rapidly urbanized west of Sheridan Boule vard. The entire drainage area extends west to the top of Green Mountain and channe l s l opes are generally mild. Green belts and park s have been l ocated along the Sanderson Gulch floodplain. Drainageway improvements have been constructed to contain the 100-year event within open howe ver roadway culverts we r e designed for the 10year freque ncy disc h arge. 2.16 Harvard Gulch (Basin 5200) H arvard Gulch flows wes t through the southern part of Den ver for a length of 5 6 miles to its confluence with the South Platte River at Wesley Avenue. The total drainage basin area is approximately 7.4 square mi l es. The High Line Cana l meand ers through the southeast portion of the basin and does intercept storm flow. Single-family residence s pri marily urbanize the basin Commercial de ve lopment is generally located along Colorado Boule va rd Broadwa y and Santa Fe Dri ve. T h e r esidential portion of the basin is very dense w ith smal l lots having an estimated 52 percent average imperviousness. The Harvard Gulch Flood Control project completed in 1 966, contains the 1 0-yea r flood underground in a box cu l vert from Logan Street to the South P I atte River. A grass-lined open channel was designed though Harvard Gulch Park with an off-line detention basin in the park. Page 17

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D enve r Storm Drainag e Master Plan Highway I-25 and the TREX construction project bisect the upper portion of Harvard Gulch. Drainage 1mprovements for TREX through tl1e Holl y Hills area include several detention/water quality basins as well as a new storm drain system The TREX storm drain is connected to Denver s existing storm drain system at two locations along the west side ofl-25: 1) the 1REX storm drain system to the south outfalls to the High Line Canal and 2) the storm drain system to the north outfalls to the existing36-inch storw drain with in Yale Avenue. 2.17 West Harvard Gulch (Basin 5300) West Harvard Gulch flows east 2 8 miles through Den ver to its confluence w ith the South Platte River 1n the vicinity of Yale Avenue The to tal area of the drainage basin is approximately 1.4 square miles The average width of the basin i s 0.66 mile and the channel s lopes range from 1.3 to 2.4 percent The basin elevations range from approximately 5,525 feet to 5,250 feet The West Harvard Gulch Basin is primarily in residential development. Commercial areas are situa ted along Federal Boulevard and a light industrial park is located jn the Basin s Jower reaches Loretto Heights College sits on the ridge that forms the sou thern boundary of the basin In the West Harvard Gulch Basin the main drainageway was piped in an underground conduit that extended from just above the Colorado and Southern Railroad to Zuni Street. This reach has been restored and an improved grass lined and concrete trickle channel carries the flood events Channel slopes within this reach are stabilized with grouted sloping boulder drops Durin g the 1 00-year flood event most of the flood flow will be conta1ned in the channeL A t the confluence of the South PI atte Ri ver the main channel flow s through an 84inch diameter concrete pipe This pipe ha s inadequate capacity to carry the 1 00-yea r flow resultin g in s hallo w flooding around th e Arapahoe Power Plant. Some pending and overtopping will occur at Zuni, Clay and Decatur Street crossings durin g the 1 00-year flood event. 2.18 Bear Creek (Basin 5500) Bear Creek generall y flow s eastward from its headwaters at Mount Evans through the towns of Evergreen and Morrison w1til it r eac hes th e metropoli tan area of Denver where it is tributar y to the South Platte The basin drainag e ba sin is approximately 36 miles long and has an average width of about 9 miles Thi s encompasses approximately 261 s quare miles of drainage area. Ele vations in the basin range from approximately 14,260 feet at Mount E vans to 5,260 feet at the mouth Turke y Creek, a major tributary drains about 52 square miles and enters into Bear Creek approximately 2 mil es down stream of Morrison. A majority ofthe basin is in the moun tai ns with th e remainder draining the foothills and high plains re gion The. dra i nage basin area inside the Den ve r s city limit s i s about 12 square mile s in size Th e completion of Bear C reek Dam in 1977 just do w n s tream of Morrison ha s a great effect on the peak disc har ges oftl1e 8.2-mile Bear Creek reach below the Dam The Dam acts as a flo od control reservoir that intercepts flows from areas in the upper and middle parts of the basin At the. Bear September 2 0 Creek Dam peak flows from th e 100-year event have been reduced from 30, 000 cubic feet per second (cfs) to approx1mately 1 000 cfs through storage in the reservoir 2.19 Maaston Lake North (Basin 5501) The Marston Lake drainage basin consists of approximately 2.2 square miles of limited developed area in the southwest comer of Den ver. Various areas within the basin are subject to flooding which could increase in severity and frequency with continued urbanization of the basin without drainageway improvements. The basin originates approximately 1h mile west of Kipling Street between Belle v ie w and Quincy Avenues, and extends approximately 4.4 miles in a northeasterly direction to its confluence with Bear Creek. Continued development in these areas, planned for mostly residential with some light co mmercial business is expected to increase runoff rates Marston Lake is owned and operated by the Denver Water Board and serves as a major link in the water supply system for Den ve r and much of the metropolitan area The Lake acts as a sump and is isolated from receiving or discharging stormwater. The drainage basin traverses vario us jurisdi c tion s and ownerships including Jefferso n County, Denver Den ver Water Board Marston Water Treat ment Plant grounds Pine hurst Country Club Golf Course, and United Sates Govern men t properties to the south efFort Logan National Cemetery. lmpro ve ment s to the drainageway have been accompl ished by the Denve r Water and b y the U DFCD The north s1de of the Marston La ke Dam was reconstructed to allow room for an open channel which along with an improvement com pleted by the UDFCD provides improved 1 00-year capacity c hannel from Old Wad swort h Boul evard to West Quincy Avenue Page 1 8

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Denver Stonn Drainage Master Plan 3.0 CAPfTA L IMPROVEMENTS PROGRAM 3.1 Cos t Mode ling Development of cost estima t es is an impot1ant component of the master planning process. Costs have been compiled to assist in the evaluat i on of drainage alternatives and to provide for systematic capita l budgeting for future impro v ement programs Bid data has been obtained from the C i ty and County of D enver for the period 1999 to 2013 and s t a t istically analyzed to deri v e regression equ at i ons that reflect typical constr uction pract i ces within the City and County of Denver, A detailed tabulation of all un i t costs and a li sting by p r oject i s s h own in the GlS Appendix and li nked to t h e GIS database for project cos t analysis General unit costs ( i n 2013 dollars ) are summarized below : Stonn Drain (18 in and < 72 in. ) : Storm Drain(> 72 in120 in ) : Elliptical S t orm Dr ain Jaqk and Bore 48 in. ) : Jack and Bore Pipe(> 48 in ) : Box Cul v erts: Headwalls: Man h oles : Manhole Cone floe Box Cul v erts Inlets : lnl e t l aterals : Stormwater Detention : Asphalt Patch (assumed 8-ft wider th an the pipe diameter) : Wet Uti l.ity Relocation Cost: $ 4 27 to $5 67 per inch diameter per lineal foot $ 5 95 to $8 89 per inch diameter per Jineal foot l Yz times the equivalent round pipe $ 27.36 per inch diameter per lineal foot $ 100 00 per inch diameter per lineal foot $ 600 percy concrete plus $0 85 per l b s teel $ 600 per cy concrete $3,181-$1 4 ,700 each Type A C, B and P $1, 800 each $ 4 200 for typica l 6-foot Type 14 curb openi n g Assumed four inlets cons tru cted per manhole Assumed 20 feet of 18-inch RCP per inlet $ 75 000 per acre-foot $ 8 00 per sy-in ($145.46 / ton) for assumed 9-inch full depth section $2 7 40 per crossing for sanitary sewer avoidance $ 1 370 to $ 2 7 360 for r e l ocation of water depending u pon s1ze Indir ect costs and co n tingency h ave been e x p ressed as a percentage of direct construction costs. T h ese include the following : Traffic Contro l : 3% Mobilization I Demobilization : 10% D esign & Engineering : 15% Materia l s Management (Limited Envi Remediation and Disposal) : 7% Cont r act Adm ini stration I Construction Management 1 0% Contingency : 25 % Environmental Compliance ( Erosion Control, etc ) 3% fNDtRECT COST TOT AL '73% Note: Property acquisition is specific to final design and not included in the project costs. S e ptemb e r 2 014 3.2 Summary of Capital Costs Cost by Project A summary of costs for a11 basins and aU projects within those basins is p r esen t ed on the following pages sorted first by bas in and then sorted by project. Costs are tabulated through automated G I S e l ectron i c master p l anning routines and are based upon unit prices developed i n 2013 In some cases, the automated costing may not match e x actly hand cal culated project costs shown in the individual Tec hnical App e ndix notebooks. However great care has bee n taken to ensure t h ese differences are w ithin 5% or less. This Drainage Mast er Plan does not d i stinguis h between Devel o p e r cos t and City cost. In particular, capita l improvements hav e been shown for new developing areas (j .e., Stapleton) although their fund in g w ill certain l y be borne by different entities and budgets than for retro-fit impro v ements of e x isting development. Cost by Basin For purposes of deve l op i ng an overall construction co s t by basin costs are summarized on the following pages to show the total cost of the Recommended Plan Thi s cons i sts of all the projects shown excluding those with an asterisk(*). Projects s h own w i t h an aster i sk have been excluded from t h e Recommended Plan in favor of a n alternative evaluated i n the same drainage basin in order to provide a level' of service necessary to drain or protec1; sump loca t ions (0060-01 0061-02) ; meet street depth criteria ( 4400-0 2, 4600-02) ; removing floodp l ain (4700-01) and other drainage cons i derations (0061-02 5100-01) The total project cost to upgrade the C i ty s storm drai n age infr astructure to meet min imum current drainage cri t eria in the Recommended Plan for t h e entire City is estimated t o be $ 1 478 025 513 in 2013 dollars Pag e 1 9

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D enve r S tonn Drain age M aste r Pl an ID OUTFALL. NAME/ LOCATI O N 0058-01 South Platte River Prairie Gateway 0059-01 South Platte River GlobevflleUtah junction 0060-01 Soi1th Platte RiVer 1-70 & Colorado BouleVard 0060-01T OOYR South P l atte River 1-70 & Colorado BouleVard 0060-02 South Platte River 1-70 & York 0061-01 South Platte River 27th & Federal 0061 02 south Platte River Highland 0061-02-lOOYR South Platte River Highland 0062-01 South P l atte River Lower Platte Valley 0063-01 South Platte River Central Platte Vall ey 0064-01 South Platte River 1st & Federal 0064-02 South Platte River Val verde 0065-01 South Platte River Ruby Hill 0065-02' South Platte River Dartmouth 0067-01 South Platte River College View 0067-02 South Platte River west Belleview 0067-03 No Outfall Marston Lake 3501-01 Second Creek W est Fork Second Creek 3700-01 First Creek First Creek & Peiia Corridor 3700-02 Flrst Creek First CreekG r een Valley Ranch 3700-03 First Creek First Creek Dogwood & Blue Gamma Tr1bs. 3702-01 Flrst Creek First CreekTributary "T" 3900-01 Irondale Gulch Irondale Gulch Stapleton 3900-02 Irondale G u lch Ironda le Gulch -East Montbetlo 3900-03 Irondale Gul c h Irondale Gulch Parkfield 3900-04 Irondale Gul ch Irondale GulchMajestic Commerce Center 3901-01 Irondale Gulch Irondale Gulch West Montbetro 3901-02 Irondale Gulch Irondale GUlch -Gateway 4000-0T Rocky Mountain Afsenal Stapleton West Section 1 0 4300-03 CfearCreek Clear Creek North of 1-70 4309-01 C lear Creek Berkeley Lake 4400-01 Sand Creek North Stapleton 4400-02-lOOYR Sand Creek Quebec Corridor 4400-03 Sand Creek Stapleton 4400-04 Sand Creek East Stapleton 4401-01 Westerly Creek Westerly Creek South Stapleton 4401-02 Westerly Creek Westerly Creek11th Avenue to Montview REC O NIMENDE D PLAN SUMMAR Y O F PROJECT C O STS B V C OLLECTION SYSTEM RECOMMEND E D P LAN NOTES CIP COST (2013 Dollars) ID O UTFALL so 4401 -03 Westerly Creek 562,253,214 4401-04 Westerly Creek Excludes Projects F and F1 & uses S T 4,280,053 1 00-year AlternatiVe 4500-01 Montclair 4500-02 South Platte S6,834,404 4500-03 Montclair SS0,044,259 4500-04 Montclair $69,285 ,056 4600-01 Cherry Creek Excludes Projects B H andJ & $70,145 ,923 uses 1 00-year Alternative 4600-02 Cherry Creek $25,199,832 4600-02-IOOYR Cherry Creel< S34,581.126 4600-03 Cherry Creek $68,436.1 29 4600-03-100YR Cherry Creek Sl 0,284, 55 7 4600-04 Cherrv Creek $29,.296.233 4601-01 Goldsmith Gulch $16,013 .182 4601 -02 Go ldsmith Gul ch 5492.60'4 53,441 705 4700-01 Sloan's Lake 52,311 ,003 4700-01-IOOYR Sloan s Lake so 4800-01 Lakewood Gulch S17.838,865 4801-01 Dry Gulch so 4900-01 Weir Gulch so 5000-01 1 25 & South Platte )1.8,999,763 5000-02 1 25 so 5000-03 1-25 Sl ,271.550 52,509,053 5 1 00-01 Sanderson Gulch so 5100-01-100YR Sanderson Gulch s 18,094,707 5200-01 Harvard Gulch $43,779 847 5200-02 Harvard Gul c h S'O 5200-03 Harvard Glll t h S6,617 ,250 5300-01 West Harvard Gulch 57,681,489 5401-01 Greenwood tulch so 5500-01 Bear Creek so 5500-02 Bear Creek Recommended Street Depth S76,51 0,599 Criteria AlternatiVe 5500-03 Bear Creek 5500-04 Bear Creek $8,926,694 5500-05 Bear Creek S26 858,165 5501 -01 Bear Creek Sl ,962,249 590.1-01 Dutci'J Creek .54,681,400 S e ptember 2014 NAME/ LOCATION RECOMMENDED PLAN NOTES C I P COST (2013 Dollars) Westerly Creek Lowry so Westerly Creek-south of Alameda s 14, 046,203 City $67,090,422 36th & Downing s 50,339,294 Park Hill Colfax $43.363,416 Par k Hill 6'11 Avenue S81 ,571,195 Central Busfness District $63,347,951 Cherry Creek Mall 568.015 612 CherrY Creek Mall Recommend e d Street Depth s 1 5.488,679 Criteria Alternatrve Upper Cherry Creek B7.029,014 Upper Cherry Creek s 1 1 .790,690 Cherry Creek Reservoir )4.961 ,467 Lower Goldsmith Gulch s 1 2 ,141 ,664 Middle Go ldsmith Gulch so Sloan's L ake Excludes Projects C1 ana D & S3,640.712 uses 1 00-year Alternative Sloan's L ake s 14,830,043 12th & Federal $8,595,513 1 2th & Sheridan so Weir Gulch $4,948,695 West Washington Park s 18,439,886 University & Mexico North s 17, 570,255 University & Mexico South $10, 387,265 Sanderson Gulch Excludes Project 0 & uses 1 00-554,928,579 Year Alternative Sanderson Gulch U ses Prqject 0 anl'y Harvard Gulch Lower Basin s 3 5 644,5 80 Harvard Gulch Middle Basin $39 ,004,016 Harvard Gulch Upper Basin $59.028,108 West Harvard Gulch $8,155,827 Greenwood Gulch so Bear Creek-Fort l.ogan S7 ,407,582 Upper Bear Creek s 13 346,391 Academy Park so Bear CreekMarston Lake North )4, 172,615 Plnehurst Tributary S3,478,670 Henry's Lake so coon creek so REC OMMENDED PLAN TOTAL $1 ,478,025,513 Page 20

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D e n ve r Stom1 D rainage Master Plan Septerl'lber .20 STATEMENT OF PROBABLE COSTS IN 2013 DOLLARS PROJECT HARDCXJSTS INDIRECT COSTS TOTALS CXJNTRACT COLLECTION ASPHALT WETUTILJlY T OTAL TRAFFIC MOBILIZATION I DESIGN & MA1ERIALS ADMINISTRA TIOI'l/ CXJNllNGENCY ENVIRONMENTAL T OTAL BY I D PROJECT PIPE MANHOLE INLETS DETENTION CONSTRUCTION CXJNTROL DEMOBI LIZATION ENGINERIN MANAGEMEN T CONSTRUCnON COMPLIANCE TOTAL COL l-ECT ION SYSTEM PATCH RELOO\TE COS T S (3%) (10%) G ( 15 %) (7%) MANAGEMENT (25%) (3%) SYSTEM (10%) A 48TH AVr= OUTFA L L (A) $13,813 353 $488 928 $1,195, 600 $1, 303 220 5310,720 $17 00 1 ,821 $512, 155 $1, 709,182 S2.5a3.n3 $1.1 96,427 $1,109 ,182 54 2(2.955 $512 ,755 $29,588,850 B 48TH AVE OUTF AL L (B) 5685, 224 57, 8 1 1 $73 200 $l76, 832 $9,590 5952,657 528 580 $95 266 5142. 899 $66 686 $95 266 $238, 1S4 528,58C S1.648 008 0Wd.01 c 48TH AVE OUTFALL (C) $5,220 660 $ 1 9 800 5268.400 $42,470 $5 ,561, 330 $ 1 66,540 $555,133 $832,700 $388 593 $555,133 $ 1 ,387, 832 $ 1 66,540 $9 603 801 E 51ST A VENUE COLLECT ION SYSTEM $5,931,143 $432. 5 1 4 S756 400 5 1 057 232 $ 1 09 540 $8 287 ,429 $248,623 5828,743 51, 243 1 14 S580, 1 20 $828,743 $2,071 857 S248 ,S2 $14,337,252 J I NTERSl'A TE 70 OUTFALL S2 521971 $72 026 5536800 $600, 752 $39 730 $3 86 1 279 5 1 15838 S386 128 5579192 $270 ,29(1 $386128 5965 ,320 $ 1 15838 56 680 013 L 49Tl-l AVE AND GRANT ST POND $240 000 $240, 000 $7, 200 $24.000 $36 000 $ 1 6 800 $2 4 000 $60 000 $7.20C $415.200 $62 .253214 F PAR K H I L L PHASE V I 51,313,488 5180 666 $3 1 7 200 5632 604 S58, 870 $2 502 828 $75,005 $250 283 S375,424 $175198 $250283 Sl:l25,707 S75,085 54, 329 893 F1 PA .RM H I L L PHASE VII 5395,922 $63 766 $97, 600 $ 1 99 272 $57.470 $814. 030 $24.421 $81,403 $122,104 $56 ,982 $81.403 $203, 508 $24.421 $ 1 ,408,27? G 50Tl-l AVE INTERC EPT O R $1, 090,449 $ 137, 998 $195 200 5315.540 $17, 810 5'1,756,997 $52, 7 1 0 5175,700 $263 550 5122, 990 $175 ,7 00 5439, 249 552,71C 53, 039,006 0060-0 1 H COLUMB I NE AND YORK UPGRADES $748, 110 $136 068 $366, 000 $6 1 4 740 $87. 800 $ 1 952 ,518 $58 576 $195, 252 $292, 878 $136,676 $ 195, 252 5488,130 $58 ,576 $3 377 858 I RNERS I D E OUTFALL $2,600,959 $30 ,265 $317 200 $2, 740 $'2, 960 16 4 588,805 $296.016 $444,025 S207.211 $'296, 0 1 6 $740,041 '$5, 121 083 L N COLORADO BLVD IMPROVEMENTS 5419,219 $67 ,587 55 1 2 ,400 820 $9 580 5'1,294,606 $38,838 $129,461 $194 19 1 $90 ,622 $129 ,461 $323, 652 $38 838 $2 239 669 M MILWAUKEE ST IMPROVEMENTS $97 750 $ 10.-329 $73 200 $108 800 $290 079 $8,102 S29 008 -543.512 $20 30 $29008 $72 520 $8702 .$501 837 $20 018.2 1 8 006(}.0 1 100YR F PARK H I L L PHASE VI $ 1 640,688 $180 666 5317"20.0 $657,144 $60,240 $2 855 938 $85,678 $285, 594 $428,39 1 $199 916 $285 .594 $71 3 ,984 585,676 $ 4 940 ,773 Ft PARK H I L L PHASE VII S655,500 $63,.766 S97. 000 5220 248 557,470 5 1 004,584 $32, 838 $109,458 $164,188 $76621 5109 .45'8 $273, 646 532838 $1,893 ,631 56,834 404 A E 45 T H AVE SYSTEM $4 1 03,680 $6 1 1,777 '$1,317. 600 $?.301..564 '$220,4 50 $8 565 ,071 $256,652 $655,507 $1, 283 .261 $598 855 $855.507 $2,138, 768 $256,652 514. 800.273 0060-02 B N BRIGHTON BLVD OUTFALL $5,868,869 $423882 $732, 000 $1.223 524 $93,120 $8 ,341 395 $250,242 $834,140 $1,251, 200 $583 .898 $834, 140 $2 085 349 $250,242 $14,430, 6 1 5 c N RACE. ST OUTFA L L $3,917,511 $439.0S2 $1, 049 200 51524,592 $ 1 93 030 57 123,395 $213,702 $712. 340 51, 068 509 $498 638 $'71 2 340 $1780 849 $213,702 5 1 2 323 ,475 D NATIONAL WESTERN IMPROVeMENTS 53 1 82 1 33 $236,431 $732,01)0 $684 340 $72,550 $4 907,45 4 $147,224 $400,745 $736,1 18 $343 ,522 $490,745 $1, 226 864 $147,224 $8 489,896 S50A044, 259 A 19Tl-l AND 23RD AVENVE OUTFAllS $1,329,434 S65 ,852 S219, 600 S::-s0.696 $24,660 $1, 990 242 $59,7U7 $199, 024 $296 ,5315 $139 ,317 $199 ,CQ4 $497, 560 $59,707 $3 ,4413,117 B 20lti AVENUE COLLECT ION SYSTEM 5 1 ,051,395 5 1 82,993 $780800 51 077 652 $152, 010 $3 244,850 597, 346 $324,485 $486, 728 5227140 $324 ,485 5811, 2 1 2 $97,34 $5 6 1 3 592 c 20TH AVENUE OUTFALL 53,712 .2 39 5261,537 58 1 0,,000 51.130.420 $ 1 16,410 $5 830,606 $174,9 8 $583,06 1 5874,59 1 $ 40 8 .142 $583 061 51.457 652 $174,91 $ 1 0 086,949 WS1.01 D 24Tl-l AVENUE COL LECTION SYSTEM $2 392,764 $309 .496 $1, 244.400 $2,011 .488 5308, 000 $6,2156,148 $187 984 $626, 6 1 5 $939,922 $ 438, 630 5626 615 $1, 566 ,537 S187,964 $ 1 0 840 ,435 E AVENUE COLLECTION SYSTEM $3, 1 9 1 ,622 $484 ,3)9 $1,122.40Q $209461 2 S294,31Q $7187,253 $215,618 s7 1 8 n 5 51, 078,088 $503 108 $71 8 725 51.796 813 $215,61 512.433 948 F 7TH STREET OUTFALL. 64 374 029 S2'19, 553 5858, 800 51.1 68,672 $ 1 88,920 $6 609,974 $ 1 98 ,2ffi S660,997 S99t ,4re S462, 698 S660,997 51, 652 ,494 $198,29!: $11,435, 254 G CENTRAL STREET COLLECT ION AND OUTFALL SYSTEM $1, 555 ,858 $239,252 $829, 600 $1, 068 '296 $266, 890 $3 959,896 $ 118,797 5395, 990 $593,984 S'Z77, 193 5395 000 $989 974 $118,797 $6 850 62 1 H U P PE R 29TH AVENUE AND UP PE R ZUNI CXJL LEC T ION SYSTEM $ 1 772 437 $271, 191 $1,024 800 $1. 661,768 $230000 $4 960 196 $ 1 48 806 $496,020 $744,029 $347,2 1 4 $496 02() $1_240 049 $148i!()f $8 58 1 .140 $69 285 056 A W 34TH/35TH AVENUE COLLECT ION SYSTEM $ 1 849 .381 5216 ,147 5927, 200 51,597.152 $282,000 $4,671 880 $146 1 56 $487.188 5730,782 5341,032 S487.168 51, 217 970 $146, 1_5 58. 428,352 8. W 34TH AVE AND LIPAN ST O UTFAL L 64,432 ,880 $87,522 $292. 800 $5 1 1 732 S15,070 $5, 340 004 $ 1 60 200 $5.34.000 $801,001 Si373, 800 5534. 000 $1 335 ,001 $160,2()( $9,238,206. c 40TH AVENUE AND FEDERAL CXJLLECTION SYSTEM $3,363,017 Si475,309 $1,317 60Q $2.375.028 $273,860 $7 804.814 $234,,44 $780,481 51,170,722 $548.337 $780 .481 S 1 951.204 S234. W 513,502,3'27 D 42ND AVENUE AND F E DERAL COlLECTION SYSTEM $1,255,075 $110,438 $780 800 $ 1 2 1 1 828 $99 970 $3 ,458,111 $ 1 03,743 $345,811 $518,717 $242, 068 $345 8 1 1 $864, 528 $103,74 $5, 982 532 E W 46TH AVENUE COLLECTION SYSTEM $ 1 ,116,206 s1n,698 5536 800 $693 184 S67, 1 10 $2.785 996 S83,5&1 $278, 600 $417, 899 $ 1 95 020 $278 000 5696 499 $83,5& 'S4, 8 1 9 .n4 006 1-Ct2 F W 47TH AVENUE COLLECnoN SYSTEM $2,303,86 5 $370.773 $9)2, 800 S1,280 020 $116,390 $4 973.848 $ 1 49 215 $497,385 $748,077 $348,169 $497. 385 $1,243.462 $8 604 756 G CHAF FEE PARK I NTERCEPTOR $1,793 065 $598,512 $1, 073 600 $ 1 ,395 ,496 $153,360 $5, 012 033 '$150,361 550 1 203 $75 1 805 5350, 842 $501, 203 $1, 253 008 $150,36 1 S8, 670 ,8l6 H. FOX STREET OUTFALL $3,786 ,424 $ 1 43,003 $268,400 5547 696 $13,700 $4,759 223 $142 ,777 5475, 922 $713 883 $333 146 6475 922 S1 1 89 806 $142 ,777 $8,233 ,456. I L OWER W 38TH AVENUE COL LE GnON SYSTEM 53 344 033 $278, 844 '$756 ,400 $1,5 1 9 308 $165,650 $6, 064,235 $181,927 $606.424 5909,635 $ 424.400 $606,424 51.5 1 6,059 $18 1 ,927 $10. 49 1127 J. LOWER JNCA STREET COLLECT ION S YSTEM UPGRACES $2,362 874 5281, 089 $683 200 51, 273 ,808 $134, 180 64, 735 ,151 SI4 2 ,05S 5473, 5 1 5 $710 273 5331, 461 5473 515 $1,1 83 188 sa. 191 813 K U PPER W 38THAVENU5CXJLl ECTION SYSTEM $2 156 533 $498036 $1098 000 $1 631512 $19.1 720 $5 575 66 1 $ 167 276 $557,586 $836379 $390310 $567 586 $1 393.965 $167 27 $9 646.239 $95 809 398 OOG1.02YR L NORTHWE S T SUBAREA INTERCEPTOR STOR M SEWER $11 ,921.236 $377,461 $883,,200 51.499, 560 $84,920 $14, 566 .377 $436,99 1 $1,456,S38 $2,184,957 $1, 019,646 $1,45S ,S38 53 ,641,594 $436,99 1 $25,199,832 $25 199, 832 F 27TH ST INTERCEPTOR PI-lASE 1 53,976.74& $ 1 30 598 $195 200 $349 ,888 5;21 920 $4, 674 354 $140,231 6467,435 $701, 153 5327, 205 5 467,435 $1, 1 68 588 $140 23 1 $8, 086 ,632 G 27TH ST INTERCEPTOR PHASE 2 $3 298,360 $202,2 98 $292 800 $680 248 $106,810 $4 580.5 1 6 $137 4 15 5458,052 $687,077 $320,636 $458,052 $1,145, 1 29 $137,41 $7 924 292 006201 1-f 27TH ST INTERCEPTOR PHASE 3 $ 1 .077.213 $237,7'E $463, 600 $733.432 S61,S30 $2, 573 67 2 $77 210 $257.367 $386,05 1 $180,157 $257,367 $643 ,418 $77,21( $ 4 .452.452 I 27TH S T INTERCEPTOR WALNUT/MARKET LA TEAA L $568,694 $97 465 $ 122, 000 5350,0"72 510.960 $ 1 ,149, 19 1 534,476 $114 9 1.9 S1n 379 $80,443 $114,919 5287,'298 $34 ,47 $1, 988 10 1 J 27TH ST INTERCEPTOR CHAMPA LATERAL $ 1 ,334,821 $ 1 12 747 $366, 000 $727, 880 $46,560 $2 588,008 $77,640 $258,80 1 $388,201 $ 181,161 $258,801 $647,002 $77, 64( $4,477, 254 M GRANT ST STORM $2 370 375 $306,2 59 $610, 000 5888,976 $247,740 $4.423. 350 $132.700 6442.335 $6S3,502 $309, 635 $442.335 51.105, 838 5132. 7()( '$7, 652 395 534.581,126 A W '13TH AVE OUTFAL L S 1 ,514,S23 $299,223 $683,200 $952,248 $136,850 $3 ,586,154 $107, 565 $358 615 $53/, 923 $251,031 $356 615 5896 538 $6, 204 046 B W 7TH AVE OUlFAll $7 397 ,2 98 $374,685 $683, 200 $985 884 $36,980 $9 448, 045 $283 ,441 $9 4 4 804 $ 1,417,2,07 $661,363 $944,80.4 $2 ,382.011 '$28-3,441 5 1 6 345 1 1 6 c WBAYAUDAVE OUTFALL $7,186,7 03 $592, 293 $2, 269 2 00 $3 1 7 9,736 $395 ,S20 $ 1 3 623 552 $408,707 $1 362 355 $2 043 533 $953,649 $1,362, 355 $3 ,405, 888 $008,707 $23 568.7 46 tl063 1 D W ELLSWORTH AVE OUTFALL 5 1,193,450 $43,769 573,2 00 $78,440 512 320 $ 1 40 1 ,179 S42,035 5140 1 1 8 $210 177 $96 083 $ 140,118 5350.'295 $42Jl35 .$2 424. 040 E W MULBERRY PL OUTFALL $'2, 535 319 S78. 176 $536, 800 S683, 124 $94,430 '53, 927 849 $117,835 5392,785 5589,177 $274, 949 5392, 785 $981,962 $6 795 .177 F W 3RD AVE OUTFALL 5'3.869, 150 $253,045 $585, 600 $672, 548 569 840 $5 ,450,183 $163,505 $545 018 $817 527 $381,513 $545,0 1 8 51, 362 546 $9 ,428, 815 G W COLFAXAVE IMPROV E MENTS $707,881 $148,075 $610 000 $607,620 $47,920 $2121 ,498 S63 645 $2 1 2 150 $318224 $148505 $212 150 $530374 $3, 670 .189 S68 4361'29 A W 3RD AVE OUTFALL $85 595 $9,543 573,2 00 5111. 724 $8,220 $288,282 58,648 $28,828 $43,242 520,180 528 828 $72.070 $8,64E $498,726 0064-0 1 B W 8lH AVE OUlFAll $699,996 $21, 905 $170 800 8293 ,460 $10 960 $ 1 .197,121 $35,914 5119,71 2 5179 568 $83,796 5 1 19,712 $'299,280 $'35,914 $2 07 1 0 1 9 c W 5TH AVE OU'TFAll $:?, 639 959 $ 141, 194 $610 000 $938, 216 $130,060 S4 '459. 4'29 $133,783 $445 9 4 3 $668 914 $312. 160 $445,943 $1, 114 857 $133 ,75:' $7 714 8 1 2 $10 ,284,557 A 18" UPGRADES 5148, 960 $29,415 $219, 600 $2,740 $595,14 7 $17,8..."4 $59 5 1 5 $89,772 541.660 559,515 $148,787 $1,029 604 B S HURO N S T OUTFAL L S168, 103 $16,684 S97, 600 S166, 1 44 $26,010 $474,541 514,236 S47.454 571 ,181 $33,218 $47,454 $11 8 ,S35 5 14 ,23 5820 955 0064.Q2 c W ALAMEOA. AVE OUTFALL $8 ,197,851 $338,22 0 $1, 073,600 S2, 1 92 ,2 20 S306,010 $12 109.90 1 $363,297 '$1, 210 990 $1,816,4 85 $847, 693 51,210 900 $3 027 475 $363,297 $20 950.128 D W ARIZONA AVE OUTFALL $1, 506 925 $46,969 $146,400 $270, 1 00 $3 4 ,230 $2,004.624 S60, 139 5200 ,462 $300,694 $140,324 $200,462 $501,156 $60 ,13 53 ,468, 000 E W TENNESSEE AVE OUTFALL S949 938 $ 1 04 338 $219 600 $450 1 20 $26 030 $ 1 750 026 $52 501 5 175 003 $262 504 $ 1 22 502 $ 1 75003 $437,506 552 50 1 '$3027546 $29 296.233 A 18" UPGRAD E S 532.490 .$29,447 $48 800 $.42,408 $153,145 $4 ,,594 $ 1 5 ,'31 4 $22 912 $10 720 $15 ,314 $38,286 $4 $26.4. 939 B S LIP AN S T OUTFALL $2,374 888 $13,454 $ 122, 000 $344,032 $38,320 $2, 892 694 586,78 1 $289 269 $433,904 $202,489 5289, 269 $723,1 7 4 566 ,7 8 1 $5,004 ,361 0005.0 1 c S PECOS STAND W ILIFF IMPROVEMENTS $1.192. 639 $ 1 76,367 $390,400 $448, 876 $21 900 $2 230 .182 566,905 $223 0 1 8 $334 ,527 $ 1 56 1 B $223 018 5557,546 566 .905 $3, 858 214 D1 WEVANS AVE IMPROVEMENTS 5878.100 5133.158 $ 1 95 200 5390,7 80 $23,290 S1.S20. 528 648,616 $ 1S2. 053 $243,079 $ 113.437 $162, 053 $405 .132 $48 6 1 $2, 803 5 1 4 D 2 WEVANS AVE EXfENS ION $1,145 559 $218 203 S317, 2 00 $611 944 565.720 ;b2359.626 570 789 $235 963 $353,944 $ 1 65,174 S235963 $589906 570 785 '$4 082 .154 $ 1S.013 !82 Page21

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D e nver Stom1 Drainag e Master Plan S!JJtember 2014 STA TEMEHT OF PROBABI.E COSTS IH 2013 DOLLARS PRO.J ECT HARD COS T S I ND I R ECT COS T S TOTALS OONT RACT COllECTION ASPHA L T WET UTILITY 10T AL TRAF F I C MOB ILJZA TION I DES IGN& MATERIALS ADM INISTRATION I CONT INGENCY Ef\N I RONMENTAL TOT AL BY I D PROJECT P IPE MANHOLE I N L !;TS DETENT I ON CONSTRUCTION CONTRO L DE'MOB ILIZA TION ENGINEffii N MANAGEMEN T CONSTRUCTION COMPLIANCE TOTAL CO LlECTION SYSTEM PA TCH RELOCATE COSlS (3%) ( 1 0%) G(15%) (7%) MANAGEMEN T (25%) (3%) SYSTEM (10 %) 00"--5-0l! A S B RYAN T S T IMPROV EMENTS $94,300 $9 ,543 $73 200 $ 104, 960 52.740 $;184, 743 58,542 $28 474 S42, 711 $19,932 $28,474 $71. 186 $8, 542 S492, 604 $492 604 0067-0 1 A S QU ITMAN S T I MPROVEM E NTS $290 500 -$31,810 $244 000 $334,040 53 1 510 $93 1 860 S27 956 $93 186 $1l9, 779 $65 230 $93 186 $232,965 $27, 956 $1,612;1l8 B W UNION AVE IMP ROVEMENTS 5345 185 sso.o06 5292,800 $31 510 $ 1 057 565 $31 ,727 $ 1 05 756 $158,635 $74.030 $ 1 00.756 $264 ,39 1 $31 ,727 $1,829 ,587 $3 441.705 0067-02 A WGRANDAVE I M P ROVEMENTS $514 559 $ 102, 943 5268 400 $406,108 $43,830 $1, 335.840 $40,075 S133,584 $200,376 $93 509 $ 1 33 ,584 $333,960 $40,075 $2,311. 003 $2 ,311 ,003 3501-01 A HIGHPO INT O PE N CHANNEL $4,2.18, 000 -$21,384 $36,864 $30 100 $4 306 348 $129 ,190 $430 635 $645 952 $30 1 444 $430 ,6'35 $1,076,587 $129 ,190 $7 449 ,98 1 c SEO:)NQ CREEK GRAffi OONTROL $5 ,7 04 ,591 $ 147: 136 $ 1 53.408 $6,005 135 $180.154 .5000.514 $900 ,770 $420.359 $600,514 $1, 501,284 $180.154 $10.388,884 $17. 838 865 A I RONDAlE GULCH DET E N TION-0 1 $975,000 $975 000 $29 250 $97 500 S146,250 568 ,2 50 $97,500 $243,750 $29 250 $1.686,750 3700-03 E' POND 802 OETENTJON $2 744.592 $11. 074 $24,400 $27 456 $2,475,000 $5, 282.522 $158,476 $528 252 5792.378 5369 ,777 $528,252 $1.;320,630 $158.476 $9,1 38.763 G I RON[)IILE GULO'i DETENTJON 06 $3, 000 000 $3 000 000 $90 000 $300.000 $450 000 $210,000 $300,000 $750 000 $90 000 $5,1 90,000 H GULQ-i DETENTJON 07 $ 1 725 000 '$1,725 000 $ 172, 500 $258 750 $120 760 $172 500 $431, 250 551750 5>!, 984,250 5 1 8.999 763 3900-0 1 A STAP LETON 1 0 $735 000 S735. 000 $22,050 $73,500 $110 250 $51,450 $73,500 $ 1 83,750 $22, 050 $1,271.550 $ 1 ,27 1 .550 A E 53RDAVE IMPROVEMENlS $259,960 $27 ,2 22 S 146 400 f>'256,080 $20 550 $71 0 212 $2 1 ,306 $71,021 $106 532 $49.715 $71,021 $ 1 77,553 $21. 306 $1, 228 666 B E MAXWELl P L I MPROVEMENTS $283 ,054 $27.312 Sl/0000 $20.550 S740 1 08 $22 ,200 $74, 0 1 1 $1t1 016 $74.011 $185 : 027 $22, 203 $1.280,387 $2, 509 053 3900-04 B E BOLLING rn IMPR OVEMEN T $ $5 43 4 ,368 $5, 025,000 5 1 0 459.388 $313,78 1 $1.045.937 $ 1 568,905 $732,456 $ 1 ,045,937 $;1, 614,842 53 1 3 .781 $16,094.707 S18, 094 .7.a7 A 18"UP GRADES $20 1 585 $28 629 $219 600 !>'2.31, 0 1 2 5>8,220 5689 046 520,67 1 $68 905 $103 ,357 $48 233 $68 905 $ 172,262 520 .671 $1, 192,050 B E 4 5 T H AV E IMPROVEMENTS $8 583 ,270 $<102', 562 $780 800 :S1 '7'Yl, 460 $197 140 $11 696 232 '$350,887 '$1, 169 623 $ 1 754.435 $818,736 $1, 169 623 52, 924 008 $350,8S7 $20,234.48 1 390 1-01 c E 47TH AV E I MPROVEMENTS S3,407,88Q $217 .9113 S1.517 ;336 $28 1 ,930 36,278 889 $188,367 $627 889 $941,833 $ 4 39,522 $627,869 $1.569 722 5 1 88,367 $10,862 478 D E 53RD AVE IMPROVEMENlS $2,794 394 $224,752 5366,000 $700,984 S50 ,650 $4 136,780 '$124 ,,03 $4 1 3 678 $620 ,517 $413,678 51,034, 1 95 $124 ,,03 E E ALBROOK OR I MPROVEMENTS $765 939 $218 ,23 1 $341 600 $485 656 .$50.670 $ 1 862 096 $55,863 5 186, 2 1 0 S27!l 314 $ 130,347 $ 1 86,210 $<165, 524 $55.883 $3,22 1 427 F E ANDREWS DR I M PROVE MENTS $230,65 1 $23 843 $170 800 $209 ,512 $8,220 $643 ,22 6 S19,2 ST $64,323 S96.484 $45,026 $64,323 $ 1 60,806 S19.297 $1,112,782 $43 779 ,847 4000-0 1 A PONDZD $3 825 000 $3.825 000 $ 114,750 5382 500 $573,750 $267.750 $382 500 $956 ,1 50 S114,750 $6,617 250 $6 ,617, 250 4300-03 A N F EDERA L 8 L VDO!JTFA LL $ 1,150 444 $179,823 $463 600 $888 ,280 $4 1 060 $2, 723 .207 $81 ) 696 $272.321 $408,48 1 S 19Q,624 $272.32 1 $880,802 $81,696 1i4 ,7'11, 148 B C LE AR CREEK OUTFAL L $1.145 000 $62 500 $122,000 $384,720 $2, 740 $1, 7 1 6,960 S5 1 .509 S171, 696 $257 544 Sl20, 187 $171,696 $<129.240 $51, 509 $2,970,341 $7, 681.469 A' 39TH AVENUE/ELM STREET I MPROVEMENTS $ 1 ,327,564 $213,665 $366 000 $638 ,32 0 $80,770 $2 626 3 1 9 $78,790 $262 632 $393,948 $ 1 83 842 $262,632 S656 580 $78,790 $4,543 533 8 1 38TH AVENUE & HOUL Y S T REET CO L LECTO R $ 3 201 603 $350.859 $610 000 $1, 114 ,884 $110.930 $5 454 276 $163,628 $545 428 $818 ,141 $381 ,799 $545,428 $ 1 ,363,569 $ 1 63 628 .$9. 435 .897. 82. 38TH A VENUE' & HOUL Y STREET CO L L E CTOR EXTENSION s-3, 478,174 $392.786 $1,171,200 $;1, 1 71 .764 '$312, ,,0 $7. 526 034 $225,78 1 $752 603 $ 1 .128, 905 3526,822 $752 603 $1.881,308 $225,781 $ 1 3 020 ,037. 4A00-02 c IV AN HOE/IVY STREET COL LECTOR LATERA L S 5418,657 $ 112,1 43 $292 800 Sl95,768 $42 470 537,855 $ 126,,64 $189 276 S88, 329 s 126 t84 $315 460 $37 855 $2,182,981 o 38TH AVENUE INTERCEPTOR* $ 1 460 164 $136 238 $244 000 $51 4.704 $12 1 810 $2 496 9 1 6 $74 ,007 $249 692 $37 4 537 S174 7e 4 S24S,692 $624,229 $74, 007 $4-3 1 9 ,864. E 39TH AVENUE $1,038 028 $ 1 66,298 $244, 000 $455,772 515,070 $1, 9 1 9 168 557.575 5191, 9 1 7 $281, 875 $134,342 $19 1 ,917 $479,792 $57,575 $3 320 161 F 2 U P PER PARK H I L L OUTFA LL $2 109 558 5317,3 38 $878 400 $1,6 1 8,004 $169 790 $5, 093 000 $152 793 $509 309 $763 964 $356,516 $509 309 $1,273 272 $ 1 52,793 $8 8 1 1 ,046. A 39TH AVENUE/ELM STREET I M P ROVEMENTS $2,253 963 $357, 664 $610,000 $1,171,836 $12 4 .600 $4 5 1 8 083 $135.542 $451. 806 $677 709 $316 264 $45 1 .806 $ 1,129 516 $ 1 35 542 $7,816,248 8 1 38TH AVENUE & HOUL Y STREET CO L L ECTOR 55 ,825,517 $377,244 5610 000 51,256,008 $143,770 $8, 2 1 2,589 $246,376 5821,254 $1,23 1 ,881 $574.878 $821 254 $2 053 135 $246,376 514 207,693 44Q(Jo.02..100YR 82 38TH AVENUE & HOUL Y STREET CO L LEC T OR EXTENS I ON $5,517,000 $512,765 $1, 171, 200 S2,S19,072 '$338, 100 -$9, 9 1 8 ,137 $297,544 $991, 8 1 4 $1,487. 72 1 $694 270 $99 1,814 $2,479 534 $297 544 $17, 1 58,378 (street d epth c IVANHOE/IVY STREE T COlL ECTOR $5 ,169, 214 $445 096 $707 600 $1,611,296 $98,630 $8 03 1 836 $240,955 $803 184 $ 1 2 04 775 $562,229 $803,184 52, 007,959 S24 0 ,!l55: $13 895 077 cntena) D 38TH AVENUE iNTERC EPT OR 53 457,792 $ 1 29 1 69 $3 17,200 S-"$5',948 $294,190 $4,794,299 $143,829 5479 430 $719 ,145 $335,60 1 $ 479, 4 30 $1, 1 98,575 $143.829 $8 ,294,1 38 E 39TH AVENUE INTERCEP T OR S 1 119 909 $ 1 66,298 $244 000 5464 624 $15,070 $2 009 90 1 $60,297 $200 990 $30 1 485 $ 140, 693 $200,990 $502 4 75 $60 297 53 ,477. 128 F2 UPPER PARK H IUL OUTFA LL S3, 506,-906 $428 267 5878,400 $1,756,272 '$171, 160 '$6 .7 41 005 $202 230 $674 100 $ 1 ,011 .151 $47 1 .870 $674 100 $1,685,25 1 S202 .23_Q $11.661, 937 $76,5' 1 0 ; 599 4400-03 A STAPLETON 04 $190,000 $37,500 $73,;<00 $ 1 40,000 $440,700 513 22 1 $44 070 $66 105 $30,849 $44.070 $110,175 $ 1 3.221 $762,411 c Q U EBEC ST OUTFAUL $3,066 ,224 5309 520 $512 400 5746,? 44 $84,850 $4_71 9 238 $14 1 ,577 $471, 924 $707 886 $330 ,347 $47 1 924 $ 1 1 79,810 $141,577 $8 1 64,283 58, 926 b'94 4400 -0<1 A STAPLETON 06 $3 701,832 $20,798 S146,4 00 $586,544 $20 530 $4 476.104 $134,283 $447 6 1 0 $671 416 $313,327 $447,610 S1,119,026 $13<1, 283 $7,7 43,659 c STAP LET ON -08 $7, 195,165 $431, 879 $ 1 ,171, 200 S2, 110,984 $139 620 $ 1 1 048.848 533 1 ,465 $1 104 .885 $ 1 657 ,327 $773 419 $ 1 1 04,885 $2, 762 212 S331, 465 $19,114 506 $26 ,858, 165 440 1-01' A STAP LETON-09 $234,076 $95,425 $536 800 $262,468 55.480 $ 1 134 249 534,027 5113 4 2 5 $ 1 70 137 $79 ,397 $113,425 $283,562 $34 ,027 $1, 962,249 $ 1 002 249 A E COLFAX AV E OUTFAL L $182.726 $17. 470 $97, 600 $ 1 73 .772 $23.270 $494 838 S14.845 $49 .484 Si4, 226 534.639 $49,484 $123 710 $14. 845 $856,071 4401-02 B E 17TH AVE OUTFALL $8135,630 $ 1 29 069 5244,000 $494,616 $46,560 $1.799 875 553,996 $179 988 $269,981 $125,991 $179,988 $449,969 $53,996 $3 113 ,78 4 c E R I CHTHOFEN PL OUTFA LL $142 844 $13,701 S97, 000 5 1 40,712 $16 440 $411, 29 7 $12 339 $41 130 $6 1 695 $28 79 1 $4 1 ,130 $102,82 4 $12 339 '$711, 545 A S Al.TOIIJ ST I MPROVEMENTS $175 440 $51.266 $73,100 $80,4 96 $10,950 $391. 352 S11 74 1 $39 135 $58 ,7 03 $;17,395 $39,135 $97 838 $11,741 $677, 040 4401-04 B E MISSISSIPPI AV E DETENTION $9751)()) $975 000 $2.9, 250 $97 500 5146,250 568,250 S97.5QO $243,750 $29 ,250 $1, 686,750 c S HAVANA STOU T FA L L $4,612 ,557 5332, 029 '$585 600 S1, 177,-444 $45 210 :$6)52, 840 -$202, 585 $675 ,264 5 1 ,011 926 $472 699 $675 284 $1, 688 ,110 $202,58 511, 682 413 A E-:33RDAVENUESYS TE M $6, 603 596 $677. 159 $ 1 561.600 $2.649,996 $238,250 $11, 730 60 1 '$35 1,918 $1 173, 060 $ 1 759 590 $821 ,142 $ 1 173,000 $2.932, 650 $351,9 1 8 $;10, 293,939 B 38TH STREET SYSTEM $670,326 $ 151, 729 S244, 000 5422 004 $36,970 S1, 525 ,62:9 $45,769 5152,563 $226,844 $106 794 $152 563 $381,407 $45.769 $2,639,338 c 40TH AVENUE SYSTEM $3,776 509 $688,028 $1,586 000 $2,202,252 $349,030 -$8, 60 1 8 1 9 $258,005 $860 1 82 $1, 290 273 $602 ,127 $860 ,182 $2,150 455 $258,055 $14 ,881 148 4500.()1 D ClTY PARK SYSTEM $1:707.771 $336 425 $800,200 S1. 1 54.000 $12 1 .870 $ 1 425,000 $5, 550 266 $166,508 $555 027 -$832:'540 $388,519 $555,027 $ 1 ,387, 566 $ 1 66,508 $9,601,96 1 E HIGH STREET SYSTEM $3,560,185 $ 182,462 5683, 200 51, 080,340 S95.860 $5, 602 047 $168,06 1 5560 205 S&10.307 S392, 143 $560 205 S1, 400,512 $ 1 6&061 $9,69 1 ,541 F JACKSON STREET SYSTEM $.460,884 $ 111, 476 $268 400 .$365,248 $88,970 $1,294, 958 $38,849 $ 129!496 $194 244 $90,647 $129,496 .$323,740 $38 849 $1,240,219 G 26TH AVENUE SYSTEM $698 ,371 $ 1 06 496 '$390_400 $667 440 $115,000 SUJ77 ,707 $59,33 1 $ 1 97771 $296,656 $138,439 $197,771 $'494.427 $59 ,331 53 4 2 1 433 H E 1 9 T H AVENU E SYSTEM $939 382 $ 1 59 ,671 $536 800 $774 040 587, 670 52.497,563 574,9'27 5249.756 537 4 634 $174,829 $249,756 $624 ,391 $74 927 $4,320,783 '$67 000 422 A MAR ION STRE ET SYSTEM P HASE1 $ 1 278,377 $ 116,407 $ 1 95 200 $320 732 $17, 810 '$1, 928 ,526 $57, 856 $192 853 $289 ,279 $13 4 ,997 $192 853 $462,1 32 $57 ,856 $3,336,352 B MAR ION STREET SYSTEM PHASE 2 $3. 418 .2 79 $288,204 $483 ,600 $921,Sl32 $60 250 S5. 132. 265 $153,968 $513 226 $769 840 $359,259 $513,226 31.283,088 $153 968 $8,878,818 c E 24 THAVESYSTEM S1,833, 195 $350,522 'S878,400 51,091, 804 $135 550 $4 .289.471 $128,684 5428 947 S643,42 1 $300 ,2_63 $428 947 $1,072,368 S12a884 $7, 420 ,785 1150002 D CITY PARK WEST DRAINAGE IMPOVEM E NTS $3 604,408 $606,882 $ 1 586,000 $2 1 37,228 'S294, 310 '$8, 228,828 5246 865 $822 883 51, 23 4 32 4 $576,018 $822,883 $2,007,207 $2 4 6 865 $14 ,235,8i3 E E 1 2 T H AVE IMPROVEMENTS $541.395 'S85,887 $658,800 $642.444 $258,620 $2 187 $218,715 $3'28, 072 $153,100 S2f8, 715 $546,7'86 S6S:61 4 $3,783,762 K N MARI
PAGE 27

D e n ve r Storm Drain age Mast e r Plan Septernber .20 STATEMENT OF PROBABLE COSTS JN 2013 DOLLARS PROJECT HAROCXJSTS INDIRECT COSTS TOTALS CXJNTRACT COllECTION ASPHALT WETUTILJlY TOTAL TRAFFIC MOB ILIZA liON I DESIGN & MATERIAl-S ADMIN ISTRATION I CXJNllNGENCY ENV IRONMENTAL TOTAl,. BY I D PROJECT PIPE MANHOLE I NLETS DETENTION CONSTRUCTION CXJNTROL DEMOBILIZAT I ON ENGINERIN MANAG E MEN T CONSTRlJCnON COMPUANCE TOTAL CO L l-ECT I ON SYSTEM PATCH RELOCATE CXJSiTS (3%) (10%) G(15%) (7%) MANAGEMENT (25%) (3%) SYSTEM (10%) A 16Tl-l AVENUE SYSTEM $5,210.444 $174.033 $707 600 $1, 200 616 $95,870 $7 388,563 $221,657 $738,856 $1,108,284 $5 1 7 199 $738 856 $1,847,141 $221,657 $12,782,213 4500-03 B G LENCXJE STREET SYSTEM 56,098,457 5347 .!'..06 $976 000 $1,839 756 $239 610 $9 50 1 389 $285,042 S950 139 $1, 425 ,208 5665 097 S950. 139 $2 375 ,347 $285,042 $16 437 403 c MONACO STREET SYSTEM $4 397,399 $609 792 $1 824,196 $221,820 $8 ,175, 607 $245 268 $817 56 1 $1,226,341 $572 292 $8 1 7 ,561 $2, 043 902 $245,268 $14 ,143, 800 $43,363,4 1 6 A JACKSON STREET S YSTEM $3,289,045 $ 1 99 330 $463 600 $704 7 1 2 $79,430 $4,736,, 17 $142,084 $473,612 $710,4 1 8 S331,528 $473 6 1 2 $1, 184 029 $142,084 $8 193 484 B HA L E PARKWAY SYSTEM $5,238,017 $ 1 96,732 $829 600 $1, 581,312 S317,520 sa, 163 ,181 $244 895 $816 318 $1, 224,477 $571, 423 $816 318 $2 040,795 $244 ,895 $14 122,302 c 81HAVENUE SYSTEM $4 100.167 $596.485 '$1. 024 000 $1.533 348 $ 1 67,080 $7,429 880 $222 896 $742 988 $1,114 ,482 $52Q092 $742 988 $1,857, 470 $222,896 $12 853 692 4500-04 D KRAMER I A STREET SYSTEM 54,010 347 $688,232 $1,317 600 $2 040 592 $ 1 93 050 $8,249,821 $247 495 $824 982 $1,237, 473 $577 ,487 $824 982 $2, 062 455 $247,495 $14 272,190 E GRAPE STREET SYSTEM $3,096,322 $432 379 S805, 200 $1, 389 690 $268 240 55,99 1 ,831 $179.755 $599 183 $898 775 54 1 9 428 5599 183 $1 497, 958 $179 755 S1D. 365 868 F JACKSON STREET S YSTEM LATERALS $1, 964 .269 $4 1 0,438 '$1.024.800 $1. 548 728 $306,610 $5.254,845 $157, 645 $525.484 $788 ,227 SS67. 839 $525 ,484 $1,313 711 $ 157,645 '$9' 000, 880 G CXJLORADO BOULEVARD SYSTEM $3,275,566 $6 19 926 $1,171. 200 $1.937 004 $321, 610 57,325,306 $219 759 $732 ,5.31 $1,098,796 $5 1 2,711 $732 ,531 $1, 83 1 326 $219,759 $12 672 779 S8t571, 195 A STOUT ST OUTFALL $2,049,040 $246 875 '$1. 3 1 7 600 $1 425 ,492 $186 210 55,225 217 $15>.757 $522 522 $783 783 765 55?2 522 S1, 306 304 $156.757 $9, 039 627 B CHERRY CREEK OUTFALLS $4,353 ,892 $496 419 '$1,537. 200 $2,079 ,582 $407,820 $8 874 913 $266,247 $887 ,491 $1,331 ,237 S62U44 $887 491 $2. 218 ,728 $266 ,247 $ 1 5 353 598 c W 14TH AVE EXTENS i ON $350,954 $35,145 5'244,000 $.347, 1 12 $31, 490 51,008 ,701 $30 26 1 $100,870 5151 305 $70,009 5100 870 $252 175 $30 26 $ 1 745,052 D W 8TH AVE OLJTFALL $400 554 $78 ,731 $244.000 $369 576 $31,510 $ 1 ,132 ,371 $33 ,971 $11 3 ,237 $169 856 $79 266 $ 113 237 $283 093 $33 ,971 $ 1 959,002 E W 9 TH AVE OLJTFAL L $907,677 $76 229 SS66. 000 5491.180 $43,840 $1,884 926 $56,548 $188 493 $282 ,/39 $131, 945 $188 493 $471 232 $56,546 $3 260 924 AQ00-01 F WEST COLFAXAVEOLJTFA L L $2, 456,051 $334 167 $1 ,049, 200 $ 1 705 7 04 $ 191, 690 $5,736,812 $172,104 $573 ,681 5860,522 5401 ,577 $573 ,681 $ 1 434,203 $ 172 104 59 924,684 G CURTIS ST OUTFALL $2,757,458 $424,743 '$1' 659 ,200 $1, 889.715 S305,250 $7,036,366 $211,091 $703 ,637 51,055 455 $492 546 $703 637 $ 1 ,759, 092 5211,091 512 172,915 H N BANNOCI< ST IMPROVEM E NTS $454.341 $103 ,391 $414 800 5489.196 $43,830 $1,505 558 $45,167 $150.556 $225 ,834 S105. 389 $150 556 $376 390 $45,167 $2,804 ,617 I N SPEER BLVD I MPROVEMEN T S $73,910 $ 1 9 086 $ 14 6 400 $96 472 $35 580 $371, 448 $11,143 S37, 145 $55.71 7 $26 ,001 S37. 145 S92 862 $11, 143 $642 604 J W 13TH AVE EXTENSION $1,1 33,566 $2 1 3 875 $439 ,200 $554,696 $80,770 $2 ,422,107 S72,663 $242 ,211 $363 3 1 6 $ 169, 547 $242 ,2.11 $605 ,527 $72,663 $4,190 ,24 5 L W 1 1TH AVE IMPROVEMENTS $548,392 $ 1 04.614 5292.800 S414 2 1 6 $58 870 51 418,892 $42,567 S141 889 $2 1 2 ,834 $99 322 5141. 889 S354,123 S42.567 52 454 683 $63,347 951 A DOWNING S T OUTFAlL $1,781,347 $371 053 $1, 268 800 51, 742, 800 $164,280 $5,328,280 $ 159, 848 $532,828 S799242 $372 900 $532 828 $ 1 332 070 $ 159 ,848 $9,217 924 a LAFAYETTE ST OUTFA LL lATERALS $68 405 S341,6fJJ $36 1 ,782 $49,280 $ 1 157,983 $3.4, 739 $115,798 S 173,69r $81, 059 $11 5,798 $289 496 $34. 139 $2 003.309 c E-STl-1 AVE OUTFALL 51, 952 770 $313 905 $1, 073.600 $ 1 192,748 $89 050 54 622,073 5138 662 $462 207 5693,3 1 1 $323 545 5462 ,207 $ 1 155 518 S 136 662 $7,996 185 0 E 6Tl-l AVE OUTFALL $1, 0 15,562 $168 ,122 $488 000 $623 152 $58 880 $2,353,716 $7061 1 $235,372 $353 057 $164 760 $235 372 $588 429 $70 6 1 1 $4,071,928 E S274, B55 $49 ,691 $292 000 $344 476 $39,690 $ 1 00 1 612 S30,048 $100 ,161 $ 150,242 S70, 113 $ 100,161 $250 403 S30,048 $ 1 732 788 4600-02 G E 890 4600.04 A 18"UPGRADES $264 ,385 $64 406 $488,000 $345 092 $20,550 $1.182.433 $35,473 $118 243 $ 177. 365 $82. 710 $118 243 $295 608 $35,473 '$2 045.608 E DAR T MOUn'! AVENUE OUTFALL $874,200 $ 1 70 698 $2.44, 000 S::..S5. 600 $10,960 $'1, 685,467 $50 ,564 $168 ,547 $252 820 5'11 7 983 S168,547 $42 1 .367 $50 ,564 $2,915,859 $4, 961,467 A 18"UPGRADES $707 590 $106 ,674 5634400 $750,200 $ 1 19 070 $2 317,934 $69 538 S23 1 .793 $347 690 $162 255 $231,793 $579 484 S69 538 $4 010 025 B E ILJF F AVE I MPROVEMENTS $758 ,851 $142 495 $317 200 $568,038 $23,200 $ 1 809 872 $54,296 $160 ,987 $271,48 1 $126 ,691 $180 .987 $452 468 S54,2g; S3. 131, 078 460 1-01 c S MONAro STREETP f
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D e n ve r Stonn Drainag e M aste r Plan September 201 4 STATEMENrOF PROBABL E C O STS IN 2 0 1 3 DOLLARS PROJECT HARDOOS T S INDIRECT OOSTS TOTALS OONlRACT OOLLECTIO(II ASPHALT WF::r UTILITY TOTAL lRAFFIC MOBILIZATION I DESIGN & MATERIALS ADMIN I STRA llON I CONTINGENCY ENV IRONMENTAL TOT AL BY 10 PROJECT P I PE MANHOLE I NLETS D ETENTION 76 $55 586 583 379 $38 9 1 0 $55,500 $138 934 $16,676 $96 1 635 J EVANS T R IBUTAR Y (EAST OF BROAOW A Y ) $7511, 811 $75 785 $366,000 $663 236 $75 330 $1,935,162 $56 055 $ 1 93,516 5290 274 $135 ,481 $193 5 1 6 $483,790 $58,055 $3,347,829 K GALA PAGOTRI BUTARY (SOUTH OF EVANS) $128 653 $11 115 $73,200 $ 1 32 016 $15 050 $360 034 $10 80 1 $36,003 $54 ,005 $25 202 SS6 ,003 $<..(),008 $10 ,801 $622,857 M GALA PAGO TRI BU TARY (SOUTH O F W E S LEYj S2CX5,795 "514,524 $112!000 $ 1 05 856 $2.740 $451, 9 1 5 $13 ,561' $45 19:? S61-7fff 53 1 ,63!1 $45 192 $11 2,979 1 $13,557 $781 ,813 0 HARVARD GU L Q-i OUT F A LL PRELIM INARY REP ORT $12 220 960 855 ,48 1 $414,800 $47, 4 56 $83 570 $ 1 2,822 ,267 $384 668 $1,282,227 $1, 923 340 $897, 559 $1, 282,227 $3 205 567 $384 658 $22,182 523 p ROSECII\LE PARK CETENT I ON $1,447 500 St,447 500 $43 425 $ 1 44.750 $217, 125 $10 1 325 $144 750 $3151, 675 $43, 425 $2 ,504, 175 S35.644 .500 A OOlUMBINE OUTFAL L $22 230 $4,004 $24 400 $29 016 $5, 460 $8519C $2 556 58 519 $1' 2.778 $5, 963 $8 519 $21 298 52,556 $147 .37'9 B OORNELL lRI B U T ARY (FlOWS TO ENG L EWOOD) $89,635 $12.724 S97,600 $109 592 $8, 220 83 1 7 ,771 $9, 533 $31,777 S47 666 S22, 2 4 4 S3U77 $79 ,443. $9 ,533 $5 4 9 ,7<14 c CII\RTMOUTH TR IBUT ARY ( F LOWS TO E NGLEWOOD) $54 085 S9,543 $73,200 $64 892 527 360 $229 060 $6, 872 522, 908 $34 ,362 S 1 6 ,CJ.jf) $22.908 $57,270 56 ,872 $396 306 D DRY GULCH MA J OR OONDUIT '$2283 168 $23 859 $ 1 95,200 $365,568 .$30. 120 $2,897 9 1 5 $86.9'37 $289,792 $434 ,667 5202 854 $289792 $724.479 'S86Jf.37 $5, 0 1 3 393 E FLORA TRIBOTARY (F L OWS TO ENGL E WOOD) $314 ,102 $42 102 $292 ,8()1) $341 ,592 $52 020 51,042 6 1 6 53 1 278 $ 1 04,262 $156,392 S?2, 983 $104 262 $260 654 $3 1 ,27 8 $ 1 803 725 G GAYLORD OUTFAL L (NORTH OF HARVARD GU LCH) $50 025 57,747 $48 800 $55,660 $4 1 0 S16S,362 $4 99 1 $16 636 524 954 $11 6 4 5 $16 636 $4 1 590 $4,991 $287 605 I HARVARD GU LCH PARK TO RACE $ 1 2 279 540 $54 676 $439,200 $60,280 $ 1 2,833 ,67 $385 0 1 0 $1,28 3,368 $ 1,92 5 .051 S898 357 $1, 283 368 $3,208, 419 $385 010 $22.202 259 520().{)2 J OORONA 517 8 366 526 234 $195 200 $2.10,588 59, 590 $6 1 9,958 $ 1 8 599 $61, 996 $92,994 $43 397 $61 996 $154 ,9(..()' $18 599 $ 1,072,52"9 K JOSEPHINE OU T FAL L $ 1 7 290 $4,004 524 400 $22,568 S5 460 S/3,802 $2 2 14 $7, 300 $11 070 $5. 166 $7 ,360 $ 1 8 450 52,214 $127,676 L LAFAYETTE OU T FAL L (NORT H OF HARVARD) $767 824 $233 894 $439 200 $47 4 ,440 562 990 $1,978,348 $59 350 $ 197, 835 $296 752 5138 484 S 197 835 $494 ,587 $59,350 $3, 422.54 1 M LAFAYETIE OUTFALL (SOU T H OF HARVARD) SW 135 $9,543 573,200 $78 ,492 $ 1 370 $222.740 $6,682 522,274 $33 ,411 $15, 592 $22 27 4 $55 665 $6,682 $385 340 N PENNSYLVANIA OUTFAll $22 3 1 0 $1,385 524,832 $4 f10 $52,637 S1, 579 $5,264 $7 896 $3, 685 $5, 264 $ 1 3 159 $1, 579 59 1 ,063 0 RACE OUTFAL L $71 085 $9 543 $73.200 $84 672 $5,480 $243,98C $7, 3 1 9 524,398 $36,597 $17, 079 524 398 $00 995 $7, 319 $422,085 p UNIVERSITY OUTFALL (NOR T H OF HARVARD GULCH) $375 1 1 8 591,602 $292, 800 $325,717 $23 290 $1, 106 ,527 $33,256 $110 853 $166 279 S77.5fJT $11 0 853 $277, 132 $-33,256 $ 1 ,917, 753 s W I LLIAMS OUTFAL L $62 ,700 $9,543 $73 200 $81,840 56, 850 $234 133 S7 ,ffi4 523,413 $35 1 20 $ 1 6 389 $23 4 1 3 S."i8,5..':\3 $7,024 $405,049" T YORK OUTFAL L $138.032 $19 187 S122,000 $152,872 $6, 850 $438,941 $ 13.168 $43,894 $65 8 4 f $S0,726 $43 894 $100 735 $13.188 $759,367 $39.00 4 0 1 6 Page24

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D enver Ston n Drainag e Master Plan 5.E;J tarnber 2014 STATEMENT OF PROBABLE COSTS IN 2013 DOLLARS PROJECT HARD COSTS INDIRECT COST S TOTAL$ CONTRACT OOLLECTION ASPHALT WET U T ILITY IOTAL lRAF fJC MOBILIZATION I DESIGN& MATERIALS ADMI N ISTRATION I CONT1NGENCY EJIIVIRONMENTAL TOTAL BY I D PROJECT P I PE MANHOLE 1NlS DElEN T ION CONSffiUCTION CONTROL DEMOBILIZATION ENGI N E ERIN MANAGEMEI'lT CONSTRUCTION 1 COMPUCINCE TOTAL SYSTEM PATCH RELOCATE COSTS (3%) (10%) G (15%) ( 7% ) MANAGEMENT (25%) (3%) S Y S'f!2M ( 10%) A AMHERST OUTFALL $154 ,904 $ 1 9 ,635 $ 1 2 2,000 $ 1 5 2,592 S12.3:!JJ $461 661 513,850 $46,166 S69 ,249 S32,316 $46, 1 66 $ 1 15 415 $13,850 $798, 6 7 3 AA STEELE OUTFALL $147 160 $23,9.40 $ 146,400 $ 149,820 S12 ,3:!JJ $479,650 $ 14 ,390 $47,965 $71 ,948 $33,576 $47 ,965 $1 1 9..91 2 $14,390 $829,796 B BIRCH" OUTFAL L $395 771 $72, 411 '$'292 ,800 $334 ,320 S:!Q, 14Q $1;1 2 5 448 $33,763 $112 .545 $ 158,817 $78, 781 $11 2 .545 $281:362 '$33,763 $1,947 02 4 BB YALE OUTFALL (COLORADO TO B IRCH) "5'1 1 69 ,003 $12,600 '$170,000 $201 ,724 .. 36.970 $1 591 ,097 $47 733 $ 159, 1 1 0 $238 ,665 5111, 377 5159110 $3f!7 774 $47.733 $2 752,599 c CLAYTON OUTFALL (SOUTH O F HARVARD GUJ.Crl) $694 9 7 5 $123 77 4 $414,800 S513,364 $102 ,690 $1,849.60 $55,488 $ 184,960 $277 ,440 5129 ,472 $184 ,960 $462 ,401 $55,488 $3 199 ,812 cc YALE OUTFAL L ( BIRCH TO CLERMONT) S251 .Z41 st800 $24.400 $46,812 ss:850 '$331 ,103 $9,933 $33,110 $49,665 $23 ,177 $33, 110 $62,776 $9,933 $572, 807 D Q..A YTON ffiiBUTARY (SOUTH OF AMHERST) 5347 ,450 $1 2 5 ,390 $292,800 S:!lJ4,888 $34,240 $1 1 04 768 $33, 1 43 $ 1 10,477 5165 .715 $77,334 5110 477 $276,1$!' $1 911,249 DD YALE OUTFALL (CLERMONT TO BRCOK) $397 ,546 $74,072 $471 ,618 $ 1 4, 14 9 $47,,62 $70,743 $33, 0 1 3 $47 1 62 $1 1 7 ,004' $14, 149 $815,900 E CLERMONT OUTFAlL "$1 ,059, 5 1 6 $216 ,975 '$683,200 $829 084 $64.300 $2,853, 185 $85,595 '$285,316 $427 975 $199 ,722 $285 ,316 $7 1 3 2 9 1 '$85,595 $4,935,975 EE YALE OUTFALL (BROOK TO DENNISON) $383 4 2 0 $3,600 $48,800 $7 1 ,440 $8 .220 S515,48C $ 1 5 464 551 5'18 $36,004 $51 ,548 $ 128,870 $15,464 $ 891 ,780 F COLORADO OUTFALL (NORTH OF HARVARD GULCH) $ 1 ,700 ,623 $315 767 $658,800 $936 ,848 $113 ,6:!lJ $3,725,668 $ 1 1 1,770 $372,567 $558 ,850 $260 797 $372 ,567 $931 417 $11 1 ,770 $6,445, 40!) FF YALE OUTFAL L (DENNISON TO DAHLIA) $477 .596 53,600 $48,600 $95,312 55 480 S6:!JJ, 788 $ 1 8,924 563,079 S94.618 544,1'55 $63,079 S157.697 $ 1 8 ,924 $ 1 091 ,264 G COLORADO OUTFALL (SOUTH OF HARVARD GULCH) $612 .094 $62,760 $43f! ,200 $637 ,180 583. 5 1 0 $1 ,834, 744 $55,042 $275 2 1 2 5128 .432 5183 .474 $458,686 $55,042 $3 1 74 106 5 20().{)3 GG YALE OUTFALL (OO.HLIA TO EUCORA) $348 2 1 8 $28,006 $48,800 $81 ,720 $ 1 0 ,960 $517,764 $ 1 5 ,533 $51,776 $77,665 $36, 2A3 $51 ,776 $129 441 $15,533 $895,731 H CCOK OUTFALL $471 ,395 $130 ,525 $195,200 $270 ,904 $60,220 $ 1 134. 244 $34,027 $113,424 $ 170, 137 579,3W $1 1 3 ,424 $283 ,561 $34,027 $ 1 ,962, 241 I DAHLIA OUTFALL 8235, 174 $27 769 $170,800 $220 720 $ 1 5 ,070 $669;533 $20,086 $66,953 $100.430 $46,867 $66953 $20,086 $1 158,291 II YALE OUTFAL L (GLENCOE TO l-IUDSON) 8392 ,083 580,233 $146,400 $183 852 $10,960 $813,5 2 8 $24 406 $81,353 $ 122,029 $56,947 $81 ,353 $203 382 $24,406 $ 1 ,407,404 J DARTMOUTH l'RIBU T ARY S6i1,283 $87 ,365 $610,000 $634, 724 $69,830 $2 ,013, 222 $60,397 $201 3 2 2 5301.983 $140.926 $201 322 5503 ,306 $60,397 S3.41Q.87 5 K AQL\MS WAY IMPROVEMENTS $95,006 $ 15 ,858 $97 ,600 593,588 $1,370 $303, 432 $9, 10 3 $30,343 $45,515 $21 ,240 530,343 575,858 59, 103 '$524 937 L DE;NNISON OUTFALL $124 ,939 $ 1 8 2 63 $122 ,000 $130 ,300 $8,220 5403,722 $ 1 2,112 $40,372 $60, '558 S28,26 1 $40,372 $12,112 $698 ,439 M EASTMAN TRIBUTARY (EAST OF FOREST) '$1 2 1 8 ,909 $324 171 $707,600 S776 ,9'JO $ 117,820 $3, 1 45,4:!JJ .$314,543 $471 8 14 $220, 180 $31 4 ,543 S786 ,358 $94,363 $5 441.594 N EUDORA OUTFALL $2,051521 $206 ,910 $488,000 $838 8 16 $73,980 $3,659, 227 $ 109, 777 $365,92 3 $548,884 $256, 146 S365,f'/23 .$914 807 $ 109,777 $6.330.464 fi GLENCOE OUTFAll OF YALE} $278, 4 7 8 $35,703 $219 ,600 $258 ,416 $3 1 ,510 $823 ,7 07 $24, 7 11 $82,371 $ 123, '556 557,659 S82 371 $205, 9 2 7 $24.71 1 $1,425,013 a GLENCOE TRIBUTARY (SOUTH O F H IGHLINE 0\NALJ 5833, 492 5208 295 $439,200 $620 ,524 $76, 6&l $2 178,191 $65,346 $217,819 5>'326,729 $152 ,473 5217 8 1 9 5544,548 S65,346 $3,758,271 u JACKSON OUTFALL (NORTH OF HARVARD GULCH) $ 108,445 51 4 109 $97,600 $120.704 $4, 110 $344,968 $10,349 $34,497 $51,745 $24, 1 4 8 $34, 497 S88 2 42 $10,349 $596;795 l/ JACKSON OUTFAL L (SOU.TH,OF HARVARD.GULCH ) $68,885 $7.]4 7 S48 ,800 $76, 672 $6, $208,954 $6,269 $20,895 531 ,343 $ 1 4 ,627 $20,895 552,238' $6,269 $361 ,490 w MANSFIELD TRI B (FLOWS TO OiERRY H I LLS V ILLAGE) $ 157,864 $32,559 $ 2 1 9 ,600 $16'4 ,632 '$23,290 $597 ,94 $17,008 $59,794 $89,692 $41856 $59,794 $149 ,486 $17,938 $ 1 034 443 X MONROE OUTFAL L $ 1 02 ,037 $16,006 $97.600 $105 .032 $ 1 0 ,960 '$331, 635 $9,949 $33,164 $49,745 $23, 2 1 4 $33, 1 64 $62,909 $9,949 '$573.72.9 $59,028, 108 A 18" U PGRADE S $24 ,890 52.9, 447 S48 ,800 $32,488 $ 135,62::> 54,069 $13, 56' 2 520,344 $9,494 513,562 $33,906 $4,069 $234 ,631 530().{) 1 B S FEDERAL BLVD I MPROVEMENTS $51 5 ,287 $157 ,981 :$341 ,600 $449.000 .$38 ,320 $1 502 188 $45,066 $150,219 $105. 153 $150 2 1 9 $375 ,547 $45,006 $2 ,598,786 c S ZUNI ST OUTFALL $1.144.235 $234 102 '$634.400 $1 0 1 4 ,480 $49,320 $3,076,537 '$92,296 $307 ,654 9461 481 521 5 ,358 S30 U54 $769 134 '$92, 296 $5 ,322,410 $8. 155,827 A 18' UPGRADES $230,565 $38, 17;? $292 ,800 $300 ,948 $ 15.070 'S877 ,55C $26,327 587.756 $ 1 3 1 633 $61 4 2 9 587 ,756 $219 ,389 $26,327 $ 1 ,518, 1 72 B S KNOX C T UPGRADE $110 ,834 $57,638 548,800 555.7 84 $2,740 $275,700 $8.2'74 527 ,580 $41,369 $19. 3:>6 $27.580 $68,949 $8, 274 $477 1 2 8 550().{)1 c S UTICA S T IMPROVEMEN T S $416,480 $72,483 $73,200 $168 ,844 $32',860 $763,867 $22, 9 1 Q $76,387 $114,580 $53, 47 1 $76,387 $ 100, 967 $22,916 $ 1 .321 491 D W AMHERST AVE IMPROVEMENTS $447 ,450 sro, 439 $463, 600 $564 ,040 $69,850 $1,625, 3 7 9 $48.761 $ 1 6 2,538 $243,807 $1 1 3 .777 $ 16 2 .538 $406,345 $48, 761 $2 81 1 ,906 F VRAIN ST IMPROVEMENTS $248,330 S1Q6,570 '$122,000 $182,980 1579,360 $22, 1 77 $73,924 $110,886 S51 747 $73,924 $ 184, 8 1 0 $22, 177 $1,278,885 $7 ,407582 A 18'' UPGRADES $107 730 $28,629 t21 9 ,600 $140 ,616 $ 2 .740 $499,315 $14 .979 $49,932 $74, 897 $34, 95 2 $49,932 $ 124, 8 2 9 $14,979 $863 ,815 B S N E WLAND S T OUTFALL 551 3 ,69f $53,996 $341 ,600 $467 ,596 $46,580 $1,423, 463 $42,704 $142,346 $213, 5 1 9 $99, 64:2 $ 14 2 .346 $355,866 $42, 704 $2 ,462,590 550().{)2 c S SHERIDAN BLVD OUTFALL "$1, H 6' ,389 $153 237 $585 ,600 5949,640 $86,230 $2 891 000 $86,733 S289, 110 $433,'664 $202 377 $289, 110 $7 2 2 774 $86,733 $5, 001 ,597 0 S WE'BS'TERST OUTFALL "$1',2 1 1. 210 '$53,548 $386 ,000 $485 ,360 $52 .020 $2, 1 58. 138 $65.044 $216,814 '$'.>'25, 22. 1 $151,770 $216, 8 1 4 $542,034 $65,044 $3 ,750,879 E W BATES AVE I M PROVEMENT S 5147 ,935, $48,533 $ 195,200 $ 174,382 $9,590 517 ,269 $57 564 S86 ,346 $40,295 557 564 $143,910 $17,269 5995 ,857 F W DARTMOUTt1. AVE IMPROVEMENTS 544,965 $6,362 $48,800 $50,048 $6,850 $4 ,711 $15,702 s:23,554 $10,992 $15,702 $39,256 $4, 711 $271,653 $ 1 3 ,346 .391 55CJn.Q4 A S WADSWORTH WAY IMPROVEME N T S $514 ,608 $84,506 $146,400 $259 008 $31 ,4/Q $1,035, 992 $31 ,080 "5103,599 $155 ,399 $72,519 $103 ,599 $ 258,9'.38 $31 ,080 $ 1 7 9 2 ,266 B GLENBROOK DETENTION BASI N & S GARRISON ST IMPROVEMENTS $402,876 $286 ,430 S390,400 S2n,928 $23,290 S 1 ,375,924 $41 ,278 $ 137, 592 5206 ,389 596,515 $137 ,592 $343 ,981 $41,278 $2.380,349 $4, 1 7 2 .615 A FOOTHI L L S GC IMPROVEMENTS $ 1 ,055.7 77 $15,905 S t 22 ,000 $140,740 $ 1 .370 $ 1 335,792 $40,074 $ 133,579 $200 ,369 $93,505 5133 ,579 $333 ,948 $40,074 $2 3 1 0 ,920 B FOOTHI L L S GC IMPROVEMENTS -0 I $45,000 $45,000 $ 1 ,350 $4,500 $6,750 $3 150 $4 ,500 $11. 250 $1 ,350 $77 ,850 c FOOTHI LLS GC I M PROVEMENTS 0;? $90,000 S9000C 5 2.700 59,000 ST3 ,500 $6 ,300 $9 ,000 $22,500 $2 ,700 $ 155,700 550(1.()5 D S HARLAN ST DETENTION-0 1 $30,000 $30,000 $900 $3,000 $4 ,500 $2 1 00 $3 ,000 $7 ,500 $900 $51,900 E S HARLAN ST DETENTION. 02 $45,000 $45,00C $ 1 ,350 $4,500 $6 ,750 $3 150 $4 ,500 $ 1 1 250 $1 ,350 $77,850 F S HARLAN S T DETEl'JTION -03 $15QOOO $ 15000C $4 ,500 $15,000 snsoo $10,500 $ 1 5 ,000 53'7 ,500 $4,500 $259 500 t G S PIERCE WAY D E l'ENTION $31 5,000 $315,000 $9.450 531,500 $47 250 $22,050 $31)j00 $78.7:xl $9,450 $_544,950 53.478,670 PrOjects shOWfl
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Denve r Stor m Drain age Master P l a n 4 0 STUDY REFERENCES ASCG Incorporate d Montclair Basin Denver Stann Drainage Master Plan September 7 2004 Atkins & Enginuity 4'h Avenue -Williams to Lafayette Drainage Stlldy Final Report F ebruruy 2 012. Atkins, Sand Creek {4400-02) and Upper Park Hill (0060-01, 4400-02 & 4500-01} Basins Final Drainage Study. J u l y 2011 Boy l e Engineering Co r poration R esul ts from First Creek Future Conditiom Model. Update july 31. 2003 Boy l e Engineeling Corpo r at i on 2003 kondale Gulch Watershed Master Plan Implementation Hydrology Model Update, July 9, 2003. BRW Inc., Lowry Master Drainage Plan Addendum No. 2 December 1 998 BRW Inc and Mat1i.x Design Group Inc Final Stapleton Infrastructure lvfaster Plan. June 2000. Cam p D r esse r & McKee, Inc. Flood Hazard Area Delineation Marston Lake North. Febr u a r y 1 979. Camp Dresser & McKee, Inc Flood Hazard Area Delineation Westerly Creek January 1977. Camp Dresser & McKee, I nc Nlajor Drainageway PlanningMarston Lake North Phase B Development of Preliminary Plan. Octo b er 1 979. Camp Dresser & McKee, I nc. Major Drainage way Planning Westerly Creek Volume 1!. Feb ruar y 1 977 Car t er Burgess, South Broadway Reconstruction : Altzona A venue to Iowa Avenue Final Drainag e Report, November 2007 Cente n n i al Eng i nee ring, lnc. Flood Hazard Area Delineation Weir Gulch Tributaries r' Avenue Dakota A11 enue J uly 1917. Ce n tenni a l E n gi n eeii n g Inc. NfcyorDrainageway PlaiWingWeir Gulch Tributariesf' Avenue Dakota Avenue Depew Street Basin July 1978 Centennial Engineering Inc. Major Drainage way Planning Weir Gulch Tributaries,. P' Avenue and Dakota A venue Phase A Report. Oc t obe r 1977. Centennial Engineering Inc Final Master Drainage Study {Lower Downtown) 20th Street Viaduct Replacement South Platt e River to Lower Downtown. August 1 992. Cente r m i al Eng i neering I n c. Nord1 1-25 Bus/HOV Proj ect Drainage Maps with SWMM Elements Aprill992. Centen niai E n gineering. I n c. North I 25 Bus/HOV Project Master Plan Sub-Basins. J anua r y 1993. S e ptemh e r 2014 CDM, Harvard Gulch/Universi ty Hills/Yale-Glencoe System Master Plan and Preliminary Design.. Ap ril 2005 CH2MH ill Glo.bevilleUtah Junction OurfaJJ Systems Planning Study for th e Urb an Drainage and F l ood Co n trol D i strict, 20 13. CH2M Hill Westerly Creek (Upstream of Westerly Creek Dam) Major Drainageway Plan for the Urban D r ai n age and Fl o od Control D i str ict & De n ver & A m ara u n derway. Chow, Ve n Te P h D Open-Channel Hydraul ics 1 959. City and County of Denver Deprutment of P u b li c Works Wastewater Management Divis i on. Denver Storm Drainage Master Plan. Jul y, 1989 C ity and County of Denver Depar tment of P ub li c Works Wastewate r Manageme n t Div i s i on. Storm Drainage Master Plane April 2005. CHy a n d County of Denver Deprutment of Pub li c Works Wastewate r Manageme n t Divis i on. Stann Drainage Design and Technical Criteria. Jan uruy 2006. City and County of Denver. Assessment D a t a Co ll ectio n Man u al. C i ty and Gotmty of Denver Deprutme n t of Parks a n d Recreation Lake Manag e men t and Protection Plan Apti l 2004 Colorado Departmen t o f Transportation, Valley Highway Logan to ff1 Avenue Record of Dedslon June 2007. De n ver County Assessors Office. 2003 Property Value Database. Enginu ity, Park Hill (NortiJ of Smid1 Road) Drainage Outfall Systems Plan Conceptual Design Report for t h e U r ban Drai n age and F l ood Contro l D i stric t Januruy 24. 20 1 2 .. ERO Reso u rces Cor p oration Draft Enviromnental Assessment kondale Gulch Preli.Jninary Drainage Study. J u ly 1 6 2003. Fede r al Emerge n cy Manageme n t Agency Mitigation D i rectorate. Engineering Principles and Practices for Retrofitting Flood Prone Residential Buildings, januruy 1995 Fo r es t City Stap l eton East -West Linear Park Detention Facility StapletonFinal Drainage Report, November 1 2002. Forest City Stap l eton Jnfrastru c ture Master PlanSection 5 : Storm water Management System, Mruch 2 0 01. Forest City Staple t o n Nord1 Stapleton lnfraslrllcture Master Plan May 2004. Forest City Stap l eton, North Stapletonliifrastrllcture hfaster Amendment No. 1 Decembe r 2006. Page 26

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Denver Stor m Drainage Maste r Plan Fores t C i ty Stap l et on Stapleron Filing No. 2Final Drainage Report December 2000. F crest C ity Stapleto n Stapleton Plannh1g Area 4 Schemalic Phase Report May 2004. Forest C ity S t a pl et on Staple ton Fillng No. 7-Final Drainage Report Sep t embe r 2006. Forest City Stap l e t on Stapleton Filing No. 18-Final Drainage Report Aptil 2006. Forest City Stap l eton, Stapleton Filing No. 19-Final Drainage Report, November 2006. Fras i e r & Gingery Inc., Major Drainagewa y PlanningSanderson Gulch/Weir Gulch Volume I Report, August 1972. Fras i e r & Gingery, Inc. Mcyor Drainage way PlanningSanderson Gulch/Weir Gulch Volume 11 Drawings A u gust 1972. Gingery Associates Inc Flood Hazard Area Delineation Bear Creek. December 1979. Gingery Associates Inc Flood Hazard Area Deli;Jeation Goldsmith Gulch and Tributm:ies 1 un e 1976. Gingery Associates Inc. Flood Hazard Area Delineation Harvard Gulch West Harvard Gulch & DiyGulch. December 1979. Gingery Associates Inc. Flood Hazard Area Delineation Sanderson Gulch & North Sanderson Gulch. August 1979. Ging ery Associates, Inc. Goldsmith Gulch Major Drainageway Planning. November 1977 HDR. Rocky Mountain Ditch Outfall Systems Planning Study, Preliminary Design Report. A u g ust 2003. H e nk e l s & McCoy, Inc. Denver International Business Center Master Drainage Plan J anuary 6 2000. H e nkel s & McCoy Inc Final Drainage Report m1d Stormwater Quality C ontrol Plan Den ve r International Business Cente r Fili n g No.8, August 1999, Revise d Januar y 7, 2000. H y d rosys t ems Engineering Consulting Service, Hydrology Study fo1 the Goldsmith Gulch Drainage Basin, October 5 1989. Hydros ys t e m s E n g ineerin g Co n sultin g Service. Appendix to Hydrology Study for the Golds m ith Gulch DrqJnageBasin Marc h 23, 1994. ICON Engineering Inc., Sanderson Gulch Drop Structure Inventory and Bank Stabilization, SouU1 Platt e River Confluence to Sheridan Boulevarct Engineering Assessment and N!aintenance Master Pian, january 2002. ICON E n g i neering In c., Weir Gulch Invent01y and Rehabilitation Plan May 2004. S e ptemhet 2014 I C O N Engineering In c. D1y Gulch Outfall Systems Plan May 2013. ].F. Sato and Associates. Coors Field Phase 2, OffSJte Draillage Bash1s Plan Sheet. Mar ch 1994 J acobs C art e r Bur gess. South Broadwa y from AriZona Avenue to Kentucky Avenue PreliJninmy Drainage Report, May 2008. Kiowa E n g in eeri n g Cor p oration, Academy Park Tributa1y to Bear CreekOutfall Systems Planning Study. D ece mb e r 1997. Kiowa E n gi n ee rin g Corporation Academy Park Tributaiy to Bear Creek Outfall Systems Planning StudyPreliminary Design Report. 1 uly 1999. Kiowa Engin ee rin g Corpora ti on Upper Weir Gul ch Mcyor Drainageway P lmwing StudyAlternative Development and Evaluation, October 1992. Kiowa E n g in ee rin g Cor poration Second Creek and Direct Flow Area 0053 Outfall Planning Stuc( y ) Preliminary Design. May 1990. Kiowa Engin eeri n g Corporation Pinehurst Tributaiy to Bear Creek Outfall Systems Planning Study. Preliminary Design Report December 1999. Kiowa E n gi n ee r i n g C orporation. Giobeville-Utah ]unction Watershed Outfall Systems Planning Study Preliminary Design Report. Februaty :woo. Kiowa Enginee tin g Corporation Creek (Lower) Drainageway Update.. Hydrolog y Report December 2008. Kiowa Engineering Corporation Westerly Creek (Lower) Drainageway Update Major Drainage way PlaiJning Phase A RepOJt, june 2009. Kiowa Engineering Corporation W esterly Creek (Downstream of Westerif Creek Dam) ME!}or Drainageway Plan for th e U rban D raina ge and Flood Cont rol D i s trict & D e n ver & Aurora july 2010. Kirkham Micha e l and Associates Master Stann Drainage Study; Fair lake Development, Revised Mar c h 1994. Kirkham M i chael and Associates Quincy Lake Phase l11 Drainage Rep011 1 un e 2003. Landmark Engineering Ltd ; Final Drainage Report on Stormwater Quality Control Plan, Gravesite Developmen t and Cemetery Jmprov eJnents Fort Logan National Cemete1y., Dec e mber 2003. L ove & Associates Inc. Prairie Gateway Outfall Systems Planning Alternative Evaluation Report. A u g ust 2002. Love & Associates, InC'. Prairie Gateway Outfall Systems Planning Preliminary Design Report Ap til 25. 2003. P age 27

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Denver Storm Drainage Master Plan Martin/Martin Inc. R evision to the First Cree k and DFA 0055 Outfall Systems Master Plan (Pi cadilly Road to Buckley Road}. Nove mber 18 1998. Martin/Martin Co n s ulting Eng ine e r s. Denver International Ailport Drainage Jvlaster Plan -Part Three Analysis of Full Development Plan, Final Report june 2004 Martin!Mattin Cons ultin g Engineers Union Pacific Realty Company Property, Phase IV anc! V, Irondale Gulch Basin Drainag e Plan J anuary 6 1 994 Martin/Mattln Co nsultin g Engineers Gateway Pa1* Parcel IV West Irondale Gulch Basin Drainage Plan October 8 1996 Matrix D es i g n Group Inc. 4f1"14rf' Stann Drain Outfall R eport, januru y 2008. Matrix D es ign Group In c., Federal Boulevard Storm Sewe.rhnprovements PrelinliJJa..ry Drainage Report, Oc tob er 2008. Matrix D es i g n Group Inc., Gulch Master Plan for th e City and County of Denver October 2009. Matrix D es ign Gro up In c., Harvard Gulch Outfall AJten1atives Analysis and Feasibility Study Preliminar y Engineering Report for t h e City a nd Co unty of D e nver May 20 10 Matrix D es i gn Group In c., Nor th Stap l eton Infrastructure Master Plan Approved Decembe r 2006. Matrix D es ign Group Sanderson Gulch-Major Drainageway Plan. April2013 Matrix De s i g n Gro up Sanderson Gulch Mcyor Drainageway Plan and Flood Hazard Area Dellneatlon, for the Urban Drainage and F l oo d Co ntrol Di s tri c t Se ptemb e r 2013. MB Co n s ulting Inc. Single Tree at DIA Filing #2 Master Drainage Plan December 18 1998. McLaughlin Water Engineers Ltd. Stormwater Outfall Systems Plan Stap l eton Area, July 1 995. McLaughlin Water Engineers Ltd South Platte River Central Platte Valley : Altemative Evaluation and Preliminary Design Report. D ece mb e r 1989. Merrick and Com pan y, Flood Hazard Area Delineation West erly Cree k Mruch 1 983. Merrick and Compatly, Outfall Systems Planning Westerly Creek East of Havana October 1996. Menic k and Co mp a n y. Urban Drainage & Flood Control Distri ct Denver, Glendale Arapahoe Co unty: Flood Hazard Delineation C herry C r eek. Jul y 1976. Merrick and Com pan y, Harmon and O'Donnell & H e nnin ger Associa t es. In c Major Dra lnageway PlanningCheJTyCreek. May 1 977. Menick and Com pan y, H armo n O'Donnell & H enninger Associates, Inc. and Alan M. Voorhees & Associates I nc Master Pla.JJ for Cherry Creek the Phase A Study Report. I uly 3 0 1976. S e ptemh e r 2014 Mose r & Associates First Creek (Upstream of Buckley Road) Major Drafnageway Plan: Co nceptual Design Report for th e U rban D rai na ge and Flood Control D istric t August 2010 Moser & A ssocia te s. Irondale G u lch Outfall Systems Plan Conceptua l Design Report for th e Urban Drainage and F l oo d Co n tro l District Sep t ember 2 011 Moser & A sso ciates, Upper Goldsmith G ulch Outfall Systems Planning Co n ceptua l Design Repor t for th e Urban D rain age and Flood Co ntrol Di s trict, November 2005. Moser & Associates Upper First C reek B aseli n e Hydrology Report, May 2009 M ull er Enginee tin g Com pan y Inc. First Creek Master Plan Ac!)ustments September 30 2004 Nelso n Haley Patt erso n & QUirk. Montb ello Storm Drainage Preliminary D es i gn. Vol. IIDrawi ngs May 1 97 5 Olsson Associates Ba.Jannwr Ditch Outfall Sys t en1s Plan C onceptual Design R ep01t for th e Urban Drai n age and Fl oo d Co ntrol District April 20 10 O l sson A ssoc iat es Marston Lake North Drainageway -Major Drainageway Plan M ay 2012 Pat due Cornwe ll & Associates Inc. Majestic Commerce Irondale Gu l c h Basin Master Drainage Plan April 8 1998. PB Americas h1c., Hydtologic 817d Hydraulic Draft Report for Denver Union Station. October 17, 2008. PB A m ericas Inc. Hydrologi c and Hydraulics Report for J(ennedy Ball Fields OutfaJJ. July 2010. PBS&] 211 ) & Federal StormwaterMaster Plan (Basin 0061-01, 0061-02). A pril 2 005 PBS&] CheJTY Creek Neighborhood Drainage Study Final Report ; May 2009 PB S&], Dutd1 Creel( Coon C reek Lille y Gulch and Three Lakes Tributary MajorDralnaageway Plan and Flood Hazard Area D e lineation Phase B October 17, 2008. PBS&] Hampden Heights Area Flood JiJVestigation and Improvement Plan June 2002. PB S&], RTD FasTracks East Co rridor Draft Drainage Master Plan Oc tober 2008. Rob erts Co n s ult a n ts, Inc., Green Valley Rm1ch, First Creek Bash1 F Outfall Study for Future Deve lopment Parcels. May 10. 2000 Rob s on S G Geohydrology of th e Shallow Aquifers in the D enver Metropolitan Area Co l orado. 1 996. Rocky Mountain Co n s ult an ts I nc. Lakeshore Village Final Drainag e Repo1t and Stormwater Management Pian Revised Januat y 2000. S.A. Miro In c ODP/FDP Master Drainage Report for Hjghpotnte, Revised December 3 2004 P age 28

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Denver Storm Drai nage Master P l a n S.A Miro Inc Master Utilities Report for Highpoime at DIA FDP/GDP Revised july 23. 2004 SA. Nliro, Inc .. C.P Bedrock Inc., Denver Connection AfasterDrainage Plan Febr u ary 28 2003 Sellards & Grigg Inc. Flood Hazard Area Delineation, Dry Gulch and Tributaries November 1977 Sellards & Grigg Inc. Evaluation of Debtis and Flood Control on GoldsmiU1 Guic!J, 1 -225 to Iliff Avenue December 2004. Sellards & Grigg. Inc. Flood Hazard Area Delineation Lakewood Gulch, February 1979 Sellards & Grigg. Inc. University and Mexico Basin Hydrology and Hydraulics Master Plan, April 2005. S i mons Li & Associates. Tnc Storm Drainage Planning Uppe r W e sterl y Creek Outfall System March 1 982 Southeast Conidor Constructors Drainage Report Area 2.2, 100% Fina.J., I 25/LRT Southeast CoJTidor. April21, 2003. Stewart, Kev i n G., P E. Flood Wan1ing and Preparedness. Mar ch 3 2003. Stormwater & Environmental Consultants Inc. A S u bdivision of Olsso n Associates, Alternatives Evaluation Report, PlaJming of Holly Hills Area Tributary to Harvard Gulch Outfall Systems. April 2000 Sto r mwater & Environmental Cons u ltants lnc., A Subdivis i on of Olsson Associates Preliminary Design Report. PlaJJJJing of Holly Hills TributaJy to HarvaJd Gulch Outfall Systems October 200 1 Tw ner Collie & Braden, lnc Lower First Creek and DFA 0055 Outfall Systems Planning Hydrology Report. August 2000 Turne r Co lli e & B r aden, Inc. City of Englewood OutfalJ Syste ms PlaJJJJing, Prelimiiiar_y Design Report, Septem b er 1 999 Turner Coll i e & Braden Inc Amended Fiiial Drainage R e port for Hampden Town Ceme1: Revised November 13, 2000. T urner Collie & B r ade n Inc. Stapleton Sitewtde Infrastructure lv!aster Plan. 1996. Tw n e r Collie & Braden fnc., Amended Master Drainage Report for Hampden Town Cente 1 : Revised A u gust 13 2002 Urban Drainage and Flood Con trol District, Colorado Urban Hydrograph Procedures 2000 v 1 2.1 and Urban D r ainage Stann Water Manageme n t Mode l (UDSWMM) 2000 v 1.4.6. Urban Drai n age and F l ood Co n tro l Di str i ct, Colorado UrbaJJ Hydrograph Procedures 2005 v 1. 4.2 and EPA Sto r m Water Manageme n t Mode l (EPASWMM) v 5 0.022. S eptemhe r 2014 Urban D r ainage and F l ood Control District. Urban Storm Drainage Crit e ria Manual Vo l umes I & II. June 2001 U r ban Drainage an d F l ood Control D i strict. Urban Stann Drainage Criteria Manual. Volutne III. September 1999. Urban Drainage and F l ood Control District. South Platte River : A Plan for the Future Chatfield to Brighton. December 1985. URS Compa n y Flood Hazard Area Dvtch Creek. Lille y Guld1, Coon C reek & Three Lakes Tributar y. May 1978. URS Company Flood Hazard Area Sloan sLake Basin October 1977. URS Compa n y Major Drainageway Planning Dut c h Creek Lilley Gulch. Coon Creek Draiiiage Basin Area Phase B PreliminaiyD e sign August 1979. URS Company ME!}or Drainagewa y Planning Sloan s Lake Basin Interim Report Phase A March 1 977. URS Company, Mtijor Drainageway PlanningSloan's Lake Basin, Phase B December 1977. U.S. A rmy Corps of Enginee r s Westerly Creek Dam and Kelly Road DamWater Co n t r o l Manual USACE. Westerif Creek Dam and Kelly Road Dam -Wate r Control Manual, April1991. Vesta l Engineerjng. Inc. Green ValJey Rand1 Final Drainage PlaJz, March 22 2004 Vestal Eng i neer i ng, Inc., Green Valley RB11ch First Creek Himala,ya to Tower Subbasin Basin Boundaries J anuary 2004. Vesta l Engineering. Inc. Green V aJJey Rand1 Master Drainage Map, Developed Basin Map. August 11, 2003 Washington Group International Globevllle Utah }un c tion Wate rshed Outfa11 System Planning ReStudy, October 2004 WH Pacific NordJwest Denver Sub-Area Drainage and Transportation Study janu
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Denver Sto r m Drain age Master Pl a n WRC E n gi neering Inc., Henry's Lake Basin Phase B Technical Addendum janua r y 1984. WRC Engineering Inc., Henry s LakeDraJnageway Phase B Report, Dec ember 1983. WRC Engineering, Inc., Major Drilll)ageway PlmmingHydrological R eport Hef11y 'sLake Basin Phase A Report. December 1982. WRC Engineering Inc., Major Drainageway Planning of Denver High Li11e Canal and Little Dry Creek Watershed (ARAPCO) Phase A Alternatives Evaluation Report, May 2003. WRC Engineering Inc., MajorDrafnageway Planning of Denver High Line Canal (Dad Clark Gulch to Mississippi A venue) Phase B Prelimlnary Design June 2004. WRC. Four Square Mile Area Storm Drainage Outfall Altemallves August 1985. WRC. Outfall System Planning -Four Square Mile Area. August 1985. Wright Water Engineers Inc. First Creek and DFA 0055 Outfall Systems MasterPlan, Preliminm y Design Report. February 9 1990. Wright Water Engineers Inc Irondale Gulch and DFA 0055 Stormwater Outfall Systems Plan Preliminary Design R eport. May 1990 Wright Wate1 Engineers In c Flood Hazard Area D e lin eaflon South Platte River : Den ver Metropolitan Area Sand Creek to Oxford Avenue September 1985. Wright Water Engineers Inc. Major DraJnageway Planning South Platte River Chatfield Dam to Baselin e Phase B 2 Volumes Nove mber 1985. S e ptemh e r 2014 Pag e 30

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CollectionS stem 0058-01 0059-01 0060-01 0060-02 43 0061-01 45 0061-02 47 0062-01 51 0063-01 53 0064-01 55 0064-02 57 0065-01 59 0065-02 61 1-Cl Cl Cl (/) 1-Cl 1-co (/) 1-co co (/) 0 1z 11-(/) (/) z 0 co ..J 1-(/) Cl 11-z <( ..J <( (/) (/) 1-<( (/) (/) 0 Cl (/) ..J cr 1-(/) z Cl (/) w a: <( u <( >-(/) ..J >-..J c;: w w 0 0 <( "' 0 ::J ..J <( z w z a: w z Cl z (;) cr 0 a: w ..J :X: ..J <( :X: w 0 w ::::> w ::::> cr 0 1-0 <( 0 0 :X: (/) 1-..J lJ.. N 0.. :X: co >-(/) u Cl :X: ::;: 0067-01 63 0067-02 65 0067-03 67 3501-01 69 3700-01 71 3700-0 2 73 3700-03 75 370 2-01 77 3900-01 79 3900-0 2 81 3900-03 83 3900-04 85 3901-01 87 3901-0 2 89 4000-01 91 4300-03 93 4309-01 95 4400-01 97 4400-0 2 99 4400-03 103 4400-04 105 4401-01 107 4401-02 109 4401-03 111 4401-04 113 4500-01 115 4500-02 121 c: 'e 4500-03 117 El 4500-04 119 "' 4600-01 123 c 4600-02 125 ... 0 4600-03 129 4600-04 133 iii 4601-01 137 4601-02 139 4700-0 1 141 4800-01 145 4801-01 145 4900-01 147 5000-01 149 5000-0 2 151 5000-03 153 5100-01 155 5 2 00-01 159 5200-0 2 161 5 2 00-03 163 5300-01 165 5401-01 167 5500-01 169 5500-02 171 5500-03 173 5500-04 175 5500-05 177 5501-01 179 w 5901-01 181 ..... u: 11-(/) 1-(/) (/) (.) <( ::;: ::::> 0 (/) 1-a: 0 ::::> 0.. Cl a: Cl (/) a: co w co w ::;: ..J co <( <( :X: (/) u 32NDAVE 26TH AVE 20TH AVE 1-(/) 0 Cl w a: <( ..J COLFA X AVE 11TH AVE 6TH AVE 1ST AVE ALAMEDA AVE EXPOSITION AVE MISSISSIPPI AVE FLORIDA AVE JEWELL AVE ILIFF AVE YAL:EAVE HAMPDEN AVE MANSFIELD AVE QUINCY AVE UNION AV,E BELLEVIEW AVE Areas w ith c ros shat c hing ar e part of Master Planned Development s. For mor e information or clarifi c ati o n c ontact D e vel o pm e nt S e rvi c es STUDY AREA MAP City & Co unty o f D e n ve r S torm Drainage Ma s ter Plan Lege nd Inte rsta te M a j o r R iver 11 __ _.1 Studied Coll ec t ion Sys t em Bo u nda ry I I Uns t u di ed Collecti o n Syst e m B o un dary f?WJ Ma ste r P l anne d Deve l o pm ent A rea c-=:c City & County of De nver Boun d a r y 0 0 1 2 4 Miles P age 3 1

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D e n ve r Stonn Drain age Master Plan Septerf'lber This page left intentionally blank. Page 32

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0 0 0 (/) 0 al al (/) (/) z al 0 (/) .... (/) z al --' .... z V) 0 fV) <( 0 --' V) V) ::i f-<( V) V) 0 :5 z 0 (/) --' .... z 0 V) 1.1.1 0: :;!; (.) <( >-w (/) (/) :.: --' :::; <( --' a: z w 0 0 <( z w 0 ...J z :::J 0: uJ 0 z 0: 0 <( 1.1.1 ...J :X: ...J V) z (.) 0 0 <( I U.r 0 iiJ :::J iiJ :::J 0: 0: 0 <( 0: :X: (/) --' u.. N a. I al u.. V) u 0 :X: :::< :::J (/) (.) <( :::< 0 .... 0 a. 0 al uJ ...J al <( (/) 32NDAVE 26TH AVE 20TH AVE COLFAX AVE 11TH AVE 6TH AVE 1ST AVE ALAMEDA AVE EXPOSITION AVE MISSISSIPPI AVE FLORIDA AVE JEWELL AVE ILIFF AVE YALE AVE HAMPDEN AVE MANSFIELD AVE QUINCY AVE UNION AVE BELLEVIEW AVE I sear Gulch ) l8100l 0 2 4 DRAI NAGE BASINS WITH AREAS OF CHANGE DENVER STORM DRA I NAGE MAS TER P L AN CITY AND COUNTY OF DENVER Legend I nterstate I I Collection System Boundary B l u e Pr int Denver Area of Change C::] City & County of Denver Boundary Page 33

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D e n ver Storm Drain age Master Plan Basin 0058-01 (Prairie Gateway) Existing Basin Description : This collection system basin is a tributary to the South Platte River and is lo cated in Denver and Adams Counties north of Stapleton The basin consists of about 1.0 I I acres tl1e northern portion which consists of the Rockv Mountain Arsenal The basin was l oosely defined in D e n ver s 1989 Master Plan and inc luded a portion of nortl1 Stapleton (south of 56th), as well as t h e P ostal Facility and Adams COlmty (north of 56\h). Basin 4400-0 I includes all area sout h of 561h Avenue in accordance with th e approved Draio age Master Plan for the Stapleton Redevelopment s ite, dated March 200L Therefore the resulting basin lies north of561h Avenue A lthough m ost of th e land in this basin i s wit hin Adams Cow1ty it is inc luded in tlli s D e n ver study for the 70-acre Denv e r Water Pump Station and Postal Facility. TI1e surro undin g area was prev ious!) part o f the Rock y Mountain Arsenal bnt bas been cleaned and t ransfeJTed to the U.S Fish and Wildlife S e rvice. which in-tum ha s transferred tlle land to Commerce City. Thi s land i s known as the Prairie Gateway which includes Dick' s Sporting Goods Soccer Stadium The site was studied in detail b y the Urban Dr ainage & Flood Con trol District Adams Cow1ty and Commerc e City in a r epo rt titled, Prairie Oateway Ou(fa/1 S ystems Planning Altemotive Evaluation Report," dated A ugust 2002. The r eport concl u ded that the 100-year storm could be retained on the s it e rather than upsizing the stonn drains tl1rough Commerce City to the South Pl atte Ri ver. The re are many existing natural depressions on the site that can contain the 1 00-year rainfaU event. Jn addition the US P osta l FaciJity existi n g retent io n b asi n s contain the 1 00-year stonn Th e Prairie Gateway r epo rt ide n tifies the m aximw11 avai labl e sto r age for the P osta] Facility as I 0 7 acr e-feet for the 30-acre parking lot and 29.6 acre feet for the 31.7 -acre Bulk Mail Facility. W ith the r edevelopme nt of the P rairie Gat eway site for the Dick's Sports Socce r Stadium. drainage east of Quebec Street and north of 56th AveJJue has been directed into two m ajor regional retention basins wit h app roxim ate l y 225 acre-fee t of reten t i on sto r age fo r the 1 00-yea r 24 h our storm eve nt. By ag reement, thes e retention basins discharge into t h e Rocky Moun tain Arsenal betwe e n storms by controll e d r eleases. September 20 1-J Page 34

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0 Key Map : ... .. .. 650 1,300 For Deta il ed Hydrology See T echnical Append i x and Work Map 63RDAVE >-5 :.:: Q_ (.) lJ.J co lJ.J ;::) 0 Commerce City 62NDAVE 59T H AVE 58TH AVE E 56TH AVE Adams County .... Collection System ...... Boundary Proposed Storm Pipe UDFCD Study Recommendations 1(/) 2 (/) 0 a: 2 1(/) :c (/)
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D e n ve r Storm Drain age Mast e r Plan Basin 0059-01 (GiobevilleUtah Junction) Existing Syst em Description: Thi s collection sys t e m basin cons ists of2.602 acres (4.07 square mile s) a nd is mo s tl y builto ut. I-25 traverses the midd le of th e basin and 1-70 trave r ses t h e southern p ortion ofthe ba s in. The 1 -25/I-7 0 interchange i s within this basin Blueprint Denver shows mu c h of the industrial a rea north east o f the 1-25/ 1 -70 interchange as '"Ar eas of Change. The north ern approximately one-third of the basin i s within Adams County. B asin dra in age is predo minat e l y wes t to cast. w ith eight m a j o r outfalls to the South Platt e Ri ver. A ninth o utfall exists at 5811\ Avenue in Adam s County Rennick railroad yard, west of I25 intercepts a significant amount of th e basin drainag e from the 'vest. 1-25 also is a b a rri e r t o the runoff du e to th e limited c r ossi ng capacity and e levated desi gn. The outfall sys t e m s sou t h of approximately T-70 have cap ac it y for t h e major stom1 (n o t including t h e railroad yard dive r sio n) The capacities of the outfall syste m s north of approximately 4th Avenue vary fro m l ess than th e 5-year flood even t to approximately a 25 year eve nt. Constraints to dra in age infrastructure in this ba sin include: Crossing the r a i lroad yard s west ofl-25 Crossing l-25 Multiple large Metro sewers jus t wes t of the So ut h P latte Ri ve r The South Platt e Rive r wes t bank leve e D rainage Deficiencies: Dra inage and t1oo ding problems in the Globe v ille Utah Junction wat e r s h e d are primari l y caused b y undersized infrastru c tur e and a lack o f drain age infrastructure. Th e existin g dra in age syste m s are typicall y w1dersized for th e 2 year even t. The 20 1 3 Globeville Utah Jun c tion Systems Planning Study b y CHM2HIII for the UDFCD provi des additional detail on draiJ1ag e d e fic iencies throu g h o ut the b asi n l11e OSP documented that the minor stotm co ll ectio n system for the ves t e m p ort i o n of the basin i s the '"' atersh e d n orth of 1-70. H owever. the O S P also confirm e d that in larger s t o rm eve nts infl ow from the Sunnyside Nei g hborhood south ofl-7 0 can e nt e r the Gl o b ev illeUtah Jtm ctio n wa t ers h e d from sou t h ofl-70 in the vicinity oflnca or J aso n Street s. The trans-basin fl ow r ates shown on the facing page are from the Gl o b evi ll e OSP not nwde lin g docum e nt e d in t h e Technic a l A pp e ndi x For purpo ses of tlli s Master Plan a I 00-year alternative i s proposed for Basin 0061-02 to intercept thi s mhoff in th e m a jor storm and con v ey it south to the South P latte Rive r This impro ve m e nt would prevent all flows from south ofl-70 from ente ring the Glob ev illeUtah Junction (0059-01) Basin Potential Inundation Areas: In a major flood. 1 -25 creates a P o t e nti a l Inund atio n Area at West 52"d Avenue and Bannock Stree t and a Pot entia l Immdati o n Area at West 43r d A ve nu e and Cahita Ct. P ote ntial inundation i s al so p ossib l e around the COOT d e t e ntion basin on th e eastside ofl-25, at 52nd Avenue and Bro a d way and the a rea located at 51 r Avenue and Washington Street becau se of topographic co n s tr a int s There's also a Pote ntial Inund ation Area in 1 -70 at North P ecos Street. Pot e n tial inw1dation i s also possi bl e in a major s t o nn event n ortl1 and eas t of the Argo Park d e t e ntion basin locat e d near East 491 h A ve nu e and Nort h Logan S t ree t. An updat e d 2dim ensio nal a nal y sis of P otential l m mdati o n Areas for the Globeville Utah Junction basin was com pl eted September 2 0 /-I for the Master Plan Updat e b y ICON Engineering. S ec the conesponding m e morandum in the te c hnical appendix for additional info rma t i on Proposed Capital lrnpovement s: The following d rain age improvements have been iden tifi e d b y the OSP and are proposed to increase the le,, el of service to a minimum of l 0 y e a r cap ac ity. Proj ec t A: 48th Avenue Outfa ll (A) The A improvement i s sized base d on th e in s tallati o n of th e I 00-year alternative L) i n basin 0061-02 (Highland Basin).Thi s project inc lud es u p s i ze d and n e \ v pip e alon g 481h A ve n ue and ultimat e l y di scharges into t h e South Pl atte Ri ve r This has m
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Key Map i 10061-01 1 iii 0 800 1,600 For Deta il ed Hydrology See T ec h n i cal Append i x and Work Map ..-. Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe ... UDFCD Study Recommendations Legend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location (' Proposed Detention Basin Existing Basin 11 Potential Inundation L.__J Area Planned Transit Line Adams Co1,mty Existing Transit Line D City and County Boundary 10060-01 1 P roposed P r o j ec t s NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. The trans-basin flow rates are from the Globeville OSP not modeling documented in the Technical Appendix. .. Commerce Cit y ... A-48TH AVE OUTFALL (A): $29,568,850 ... C -48TH AVE OUTFALL (C) : $9,603,801 -+ E 51ST AVENUE COLLECTION SYSTEM: $14,337,252 .,. JINTERSTATE 70 OUTFALL: $6,680,013 Basin 0059-01 Globeville Utah Junction

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D e n ve r Storm Drain age Mast e r Plan Basin 0060-01 (1-70 & Colorado Boulevard) Existing Syst em Description: This collection sys t e m basin includ es a mix of indust r ial and reside ntial lan d u ses and consists of 1.3 71 acres ( 2 .14 square mil es). It is full y built-out w ith older n e ighbo r h oo d res i dential in th e u pper reac he s a nd commercial ill the l owe r reaches. Blueprint Denver s how s the region do w n stream (northwest) of Vasquez Boul evar d as an 'Area of Change Th e upp e r reaches ofBas in 0060-0 1 are shown as 'Areas ofStabili.ty". All drain age from thi s basin outfalls t o the South Platte Rive r Runoff i s co n veyed thr o ugh the basin primaril y by th e s tre ets as surtace fl ow. witJ1 several stonn drain p ipes a ls o co n veying wate r to th e north Some ofthe stonn drain pipes te rmin ate at the City limit or at the Par k Hill (Triangle) detention basin b efore runoff co ntinues into Adams County and into th e S o uth P latte Ri ve r. This basin i s se r ve d b y two primar y outfalls: a 4 2-i n c h diam e t e r pipe a lo ng York Str ee t a nd a relati ve l y small ope n e haw1 e l north of the Park Hill (Triangle) de te n t ion ba s in runnin g al o n g the Union P acific and Roc k Island Railroad s through Adams Co unt y This basin is situate d at the bottom of seve ral other m ajo r drain age basin s. Durin g m ajor s t01m even t s b asin 0060-01 can pot e ntiaU y r e ceiv e trans-ba sin surface runoff tl:om a number of other b as in s including P ark Hill 44 00-02. 0060-02. and Montclair 4 500-01 (thr o u g h 0060-02) A total of five tran s-bas in ove rland flowpath s are in this basin during th e Three of th ese are inflows from basin 0060-02 at th e upst r ea m (sout h) p o rtion of th e basin and t wo a r e fr o m basin 4400-02 at the southeast p o rtion of the basin inflo ws fr o m 006 0-0 2 occur along Brighton Boul evar d and th e B NS F Railroad : along the UPRR near I-7 0 an d York Street ; and across I-70 at Fillmor e Street. Inflows from b asin 4400-02 are received from th e east al o n g Smith Road n ear Forest Street and at the Park Hill Golf Course near 38' h Avenue and D ahlia Street. A portion of th e wat e r f rom 4400-0 2 continues t o t low t o the eas t along Smith Road and into b asin 0060-02 w hil e a p o rti o n overtops t h e UPRR and flO\".' S n o rth in basin 0060-0 1 i n a major storm eve nt. Drainage Deficiencies: Th e exi s tin g drainag e s ys tem has capac i ty to con vey l ess than the year s torm eve nt to th e outfal l. R ainfall nmoff in excess of t h e storm drain capacity has a histot y of pondin g in the sump and flat areas. Major drainage prob l e m s ha ve been ex p erie nced alon g t he Smith Road conido r at Dahlia, along V asq ue z B ouJeva rd near S a nd Creek al o ng Yor k Street. a nd at th e Denver Wate r R ecycle P la nt l oca t e d in Adams Cou nt y just do w n stream of D e n ve r s c i ty linllt. Specific draina ge d eficiencies include: Th e exis tin g Union Pacifi c Ra il road (UPPR) rightof-way c reates a major barrier for surface tlo w and causes bro a d floodin g of t h e Swansea Neighborhood Impro ve d convey ance (stmm drain) i s n eede d in York Street up strea m of Brighton B o ulevard and in the indus trial zo n es up stre am ofVasquez Boul eva rd Dra in age d efic i e ncies at th e bas i n s outfa ll t o the Sout h Platte Rive r have b ee n d ocume nt e d b y E ng imtit y for th e Urban Drain age and Floo d Contro l Di stric t in a repmt titled Park Hill (North of Smith Road) Drai11age Outfall Systems Conceptual Design R eport. dated Januar y 24 2012. A port io n o f the are a includ e d in thi s st ud y l ies in Adams Colmty o utsid e of D enve r's board ers. but D e nver wouJd b e a coope ratin g p a rtn e r for the show n as Proj ect I, since i t serves as th e primru y outfal l for mu ch of Bas in s 0060-01 and 4400-02. Potential Inundation Areas: An area of potential in u ndation h as been id e nti fie d w ithin Ba sins 0060-01, 0060 02 and 4400-02.. related primaril y t o ponding b e hind rail road tracks 1 -70 and other s ump s in th e Jower porti o n s of eac h bas in September Proposed Capital Improvements: Draina ge improv e m e nt s in t h ese basin s s houJd be v iewed primaril y to achieve the minimum p erfonnance o b jectives for residential and commercial areas ( 2 and 5-year s t orm drain syste m capacities and street co n veyru1ce in l arge r st01m events) estab li s h e d for th e D e n ve r s t ormwate r pro gram primari l y d u e to th e hig h cost of retrofitting new stonn drai11 i11 existing streets. Proposed capital impro ve m e nt s in clu de: Pr oject F: Park Hill Pha se VI A nev v 5-yea r s t onn drain sys t e m is n ee d e d in Dahlia Str ee t Thi s propos e d proj ect will connect d ow nstream to the plann e d 84 Park Hill Phas e V stom1 drain at Dahli a Stand S mith R oad (currentl y in d esig n ) and Project F I ups t ream Proje c t FI : Park Hill Ph ase VII A ne w 5-year stonn d rai n s yste m is n ee d e d in Dahlia Street. TI1is p ro pos e d proj ec t w ill con n ec t downs trean1 to Proj ect Fat E. 38th Avenue and 4400-0 2 Project F2 upstr e am. ProJec t G : 50th Avenue li1te r cc p tor A new sto rm drain svste m i s n ee d e d in 50o. Avenue This proposed proj ect w ill co n nect to the exist in g P a r k Hill Phase IT sto nn drain system at 501 h A venue and Co l o r ado B o ul evard. Proj ec t H: Columbine and York Upgr a d es A 5 vear storm dmi n s ys t e m is n ee d e d i n Brighton Boul ev ard fiom York S t r ee t exte nd i ng sou th i11 Brighton B o ule v ard Y o rk Street and Cohunbinc Street. Pr oject 1 : R ivers id e OutfuJl A 10 0-ycar 9'x6' outfall s t orm drain i s proposed v'
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Key Map ... . .. = i E ii .. ::: co !; 0 0 g -.;; g D lit ( 0059-01 ) l Q. I e 1l 0 11! 650 1,300 Feet ;:: 1 inch equals 1,300 feet ': '; : !::::: -<:" g : j V) \ \ For Detailed Hydro log y See Technical Appendix and Work Map Adams County Commerce City .. .... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Thalweg Proposed Storm Pipe --UDFCD Study Recommendations X Proposed Pipe Disconnect Legend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location ;- Proposed Detention '-.J Basin Existing Basin 11 Potential Inundation L__J Area -+--Planned Transit Line Adams County ( 4500-01 1 -+-Existing Transit Line D City and County Boundary .... .: Other Municipalities D Other Counties Proposed Projects NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. ( 4400-03 ) F-PARK HILL PHASE VI : $4, 329,893 F1 PARK HILL PHASE VII : $1,408,272 G-50TH AVE INTERCEPTOR: $3,039,606 H COLUMBINE AND YORK UPGRADES: $3,377.858 I RIVERSIDE OUTFALL: $5,121,083 L-N COLORADO BLVD IMPROVEMENTS : $2,239,669 MMILWAUKEE ST IMPROVEMENTS: $501,837 Basin 0060-01 1-70 & Colorado Boulevard Denver Storm Drainage Master Plan Page 39

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D e n ve r Stonn D rai n age Mast e r Pla n Basin 0060-01 (1-70 & Colorado Boulevard) (Alternative 100-Year Basin) Proposed 100 Year Alternative Capital Improvements: P ro ject F and F 1: Park Hill Phase Vl & V U Stonn drain alig n m e nts shown in th e I 00ycar al t e mative from Project s F and Fl ar e th e same aJigmn e n t s for t h e minor sto rm Pipe sizes have i n creased for the 1 00year altcmati vein o rder to reduce surface runoff d e pth s in th e stree t to 1 2 -i nches in the g utt e r in accordance w it h D enve r street-de pth crit e ria Thi s analysis i s based on the July 2011 Sand Creek (4400 02) and Upper Park Rill (0060 01 4400-02 & 4500-01) Basin s Final Drainage b y Atkins. See t h a t stud y for a dditional alternatives September 201-/. P age 40

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Key Map .. E c ;; "' :ii 11 E oi. > 0 .8 g. ::; c.' ::; 0 V> ( 0059-01 ) 0 g g. l Q. e 0 .!!! 650 1,300 Feet ;:: 1 inch equals 1,300 feet . "' Q:: : \ Cl. -<::' : : V) \ . I I \ .. \ For Detailed Hydro log y See T ec hni cal Appendix and Work Map Adams County Commerce City .... Collection System ...... Boundary t:t Topographic Basin -'Boundary : 100-yr Sub Collection System Boundary Thalweg Proposed Storm Pipe UDFCD Study Recommendations X Proposed Pipe Disconnect -L egend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location r -. Proposed Detention Existing Basin 11 Potential Inundation L....l Area Transit Line [ 4500-01 1 Existing Transit Line D City and County Boundary ...... ,: Other Municipalities D Other Counties NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. ( 4400-03 ) Proposed Projects F-PARK HILL PHASE VI: $4,940,773 Basin 0060-01 1 00-yr Alternative 1-70 & Colorado Boulevard Denver Storm Drainage Master Plan Page 41

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D enver Stonn Drainag e Master Plan Basin 0060-02 (1-70 & York) Existing System Description : This collec t ion system bas i n consis t s of 93 4 acres ( 1 .46 s quar e miles) and is fully built-out with older ne i g hb orhood residential in the upper reaches and industrial in the lower reac h es l11e Na tional Western Stock Show gro und s arc l ocated within this drainage basin Bluep rint D enve r s ho ws the industrial portions ofthe basin as .. Areas of Change Only the r eside ntial neighborhoods arc shown as 'Ar eas of Stability ". All draina ge from this basin outfalls to the South Platte Rive r Int erce pt ed s t omnvater i s discharged to th e South Platt e Riv e r via at l eas t 12 stom1 drai11age outfalls H oweve r the only o n e major (la r ge r than 48inc h) outfa ll exists at R ace Co urt j u st up st r eam of th e Burlin gton D itch hcadgat e Thi s outfall ( D esig n Point 1 549) local l y drain s 59 7 ac r es tribut ary areas di sc h a r g in g via a 78inc h pip e and paralle l 42-inc h pipe whic h h ave a tota l ca pacity of abo ut 4 1 0 cfs Follo w in g th e c rit eria o f a n 80% full f low pipe. the existi n g sys t e m has l ess than a 2 yca r l eve l of ser vice w h e rea s c urr e nt criteria requir es a 5-yca r le ve l of se rvice for co mm e r cial/ind u strial areas Constraints to draina ge infrastructure in this basin include : Crossing a major raiJ sw itching yard west of Blak e Street Crossing 1 -70 Crossing the BNSF R ailroad next to Brigh ton Boul eva rd An eleva t ed sectio n of the Metro S ewe r along the South Platt e River. creati ng a waU barrier for drainage While this basin i s locally serve d by seve ral smal l stonn drains wit h a maste r plarmcd goal of conveying the minor 2-or 5-year eve nt. the basin also experi ences pass through' flow fro m other basins during a major storm event. A t otal of four trans-basin overland flow pa t h s are observe d in this ba si n during the major-event. Three of these a r c inflo ws from basin 4500-01 (Montclair) a t the upstream (south) portion ofthe basin Specificall inflo ws occur at th e UPRR [ ntermodal Facilit y a t 40th Avenue and High Street; at 40'h Avenue a nd York Street: and a t th e M arke t Lead jus t eas t o f 40th A venue and Mad iso n Street. Add iti o nall y, o n e inflow fro m ba sin 0060-0 I (orig inall y from 4400-02) flow s west alon g S mit h R oad and the UPRR and e n ters thi s ba sin at the Market Lead wes t of Colorad o B ou l ev ard Som e ofthis tran s -basin major -event nmoff continues duough ba sin 0060-02 and e11ter s ba sin 0060-0 l at vario u s points Til ese l ocatio n s inc l ude along Brighto n B oulevar d and th e B NS F Railr oad along th e UPRR near l -70 and York Str eet. and across I70 at Fi1Jmo re Street. Pote ntial Inundatio n Area s: H ydrau l ic analys i s shows areas around the National Wes t ern Stock Show Co mplex to be s ub ject to potential inUJldation during m ajor s tonn eve nts l11ese areas are located alo n g the South Platt e R iver Vall ey and at l ocal i zed a reas and s u mps. R e d eve l opment of the sit e wou l d warrant drai n age improveme n ts in this area. A second area of poten ti al inundation in this basin i s the result of o v erflow from Ba sins 4400-02 and 006001. Runoff from these b asins e n ters B asin 0060-02 along Srrutb R oad and c r osses 46th Ave nue between N. Clayton Street and N. Stee l Str eet, and flows overland back int o Basin 0060-01 Altemative drainag e impr ove m e nt s in these basins may reduce th e threat of pot e ntial inundati o n in this area Anothe r area of pot e ntial inundation is the r esul t of overland flo w fro m the M ontc l air B asins ( 4500). R u noff i n excess ofrh e pip e capac i ty w ill e nt e r b asin 0060-02 so uth ofl-70 n ca r 401 Avenue and continue to flow in September 2 0 1-J a northerly and northwesterly direction through the basin. Drainage improvements associated"' ith C OOrs proposed lowering and reconstn1ction of 1 -70 will need to address this off-site runoff from Mo n tclair l1lis is cu rrent! b e in g eva l u ate d in the Montclair Outfall Sys t e m s Planning Study by the Urban Drainage & Flood Control D istrict (UDFC D ). funded by the UDFC D and D e n ver. Drainage Defi cie nci es: The ex isting drainag e system generally ponds water b eyon d a 2 year stonn event with significan t widesp r ead areas of pot en tial inundation expec t ed to occur during a I 00-yea r event. Proposed Capital Improvements: Th e trans-basin overland flows we r e not tak e n int o co11s ideration whe n sizi n g the propo se d proj ects ide ntified herein. If u ps t ream prop ose d p rojec t s are co n s tntcted tor th e lOO-year storm eve nt the trans-ba sin t1ows wi II b e int e r cepte d b y the propo se d sys tem s in eac h b asin and th e r e w ill b e no mor e tran sbasin flow Four major storn1 d r ai n project s h ave bee n p ropose d in this basin to increase the level of se r v ice f r om a 2-ycar capacity to a 5-year capacity. Project A: East 45th A ven u e Svstcm Thi s project includes an exte n sio n of th e latcml network so uth ofl70. Currentl y stonnwatcr is collected in 45th Avenue. These improve m e n ts the s t orm drain s into 44lh and 43rd Avenues Pr ojec t B: North Bri Q h ton Boul evard Ou tfal l This proj ec t involves construct i on o f a n e w o u tfall a t a new l ocation There is no easy or o b vio u s new outfal l r ou t e to the South Platte River : access is eithe r restricte d by 1-70 or the Stock S h ow comp lex. To maximize the use of th e existi n g pi pe network a ne\ 96-inc h outfall has been proposed fro m Y ork Street & 45th Avenue through th e National Western Stock S hov g r o und s t o th e South Platte River. Negotiations are needed to obtain an case ment for a new drainage outfall iJ1 this area if the existing outfall is to remain witho ut rep l acement. Ot her minor outfall pip es a l so need to be ups i ze d in o rder to impro ve th e l eve l of se rvic e in t h e area. Proj ec t C: No rth Rac e Str ee t O u tfall Th is proj ect invo lves up s i z i ng ex i stin g storm p i p e nort h of 1 -70. l11e railroad i s a maj o r b arrie r for construc tin g new pipe in thi s area There arc few r oadway c r ossi n gs of the railroad in t h e ar ea. Th e 9 1 -acrc area (sub-basin 520) n ortheast of Va s qu ez Bou l evard a nd [-70 is currentl y drain e d by an 1 8-inc h pip e under 1-70 The propos e d pipe tbllo ws a n ew alignment in 481h A ve nu e to avo id constmction i n the J 70 corri dor P rojec t D : National W es t e m T mproyements Thi s proj ec t involves enlarging exis tin g stonn dr ain outfal l s ncar I -70. Sp ecifical l y a 30-inch o utfall south of l-7 0 (D es ign Point 6 10) i s up size d to a 48-inch pipe A 24 inch outfall north ofl-70 ( D es ign P oint 600) is upsized to a 48 inch pipe A 30-inch o u tfall north of 1 -70 ( D es i g n P oint 590) i s upsized to a 54-inch pipe Prelimina r y design may consider paral l el pipes for this p r oject r at h e r than com pl ete r eplace m ent. P age 42

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Key Map 0 600 1,200 ( 0059-01 ) For Detai l ed Hydrology See Technical Appendix and Work Map ...... Collection System ...... Boundary Proposed Storm Pipe 1-1-1(/) (/) (/) LLI z LLI LLI 0 a:: ::.:: 1-0 :::> ::2 -' -' u -' z u: z z ( 4500-01 ) Legend Existing Storm Pipe ;' Proposed Detention Basin ( 0060-01 ) 1(/) w -' w w 1(/) z E40THAVE II I] I I N 8 oo,o -+-Existing Transit Line D City and County Boundary ..... UDFCD Study Designed Storm Improvement Existing Basin I" 1 Topographic Basin Recommendations Boundary --Existing Surface Flow 11 Potential Inundation : Other Municipalities P roposed P rojects NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. .... AE 45TH AVE SYSTEM: $14,800,273 ..... BN BRIGHTON BLVD OUTFALL: $14,430,615 .... CN RACE ST OUTFALL: $12,323.475 ..... D-NATIONAL WESTERN IMPROVEMENTS: $8,489,896 Basin 0060-02 1-70 & York Feet Proposed Pipe L__J Area ___________________________________________ _____________ x ____ D is c o nn e c t _______________ ____ s _ig_ n ir ic a nt F Ioo ___ d in g L oc a tio n ____________ P Ia n n e d T ra n sit L in e ___ ______________________________ Pag e 43

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D e nver Storm Drain age Master Plan Basin 0061-01 (27th and Federal) Existing Syst .em Description: The 27th and Federal collection system bas in i s l oca t e d in northwest D enver. The approximate b o undari es of the basin are W 1 9111 Avenue o n the south (Sports Authority Fi e ld at Mil e High Sta diu m) W. 34'h Avenue on th e north the South Platt e Ri ve r to the east a nd a varying e dge on the west ptimaril y eA_"tendin g toN. Newt o n Street with some portions e:-.1endin g as far west as N. Wolff Street. Th e b asi n i s compri se d of appro x imate l y 1 ,428 acres ( 2.23 sq mi) of full y d eve l ope d a rea. The basi n gen e rall y drains from wes t to east and h as multiple outfalls into the South Platte Ri ver. The basin i s compose d of a variet y of land u ses including r e side11tial parks commercial and industri a l land u ses. Much of th e b asin i s r eside ntial vvith comme rcial areas primarily l ocated along F e d e r a l Boulevard and tl1e ( -25 corrid o r Blueprint Denver shows the area w ith i n Y z mile of 1-25 botUJded o n the east b y 1-25. W. 20\h Avenu e on t h e south and W 33'd Avenue on the North as an area s ubject to change. The remaind e r (ov e r three-quart e rs of th e b asin) i s shown as being au ''Area of Stabilit y". All drainage from this basin outfalls t o t h e South Platte Rive r In te rcepted stonm, vatcr i s discharged in over 9 se p arate stonn drainage outfaJJs w hich cross under 1-25, uJt i mate J y discharging into the Sou th Pl a tt e. Some of t h e more maj o r o utfall s includ e: 50-inch pipe at W 20th Avenue and N. B rya n t Street 4 8 -inch x 72-ineh pipe at W 25th Avenue and W B yron Place 5 ft x 8ft box culvert at Central Street and l9'h Street Drainage Deficiencies: In geheral : much of the existing syst e m is tmd e rsized an d docs not ade qu a t e l y con vey t h e 2-year or 5-year desi g n flows. Storm drain infrastructure in t hi s bas i n h as unders i ze d outfalls incomplete n etwo rks of stor m drain l a teral s and is primaril y composed of brick a nd clay pipe syst e m s which d o not meet Denver Pub l i c W o rks' current drain age criteria for s i ze a nd/or material. M u ch of the system "vas previo u s l y a part of a combined sewe r sy ste m w hich h as s in ce been se parated from th e sanitar y component. The 27th and F e d eral basin lies o n a r e lativel y steep a rea o n th e si d e of t h e Sou t h Platte Ri ve r Valley. As a result water te nd s t o move quickly through the bas in and generall y does not produc e areas of severe ponding Howeve r there are two major flo w paths w i thin the ove rall b asi n that d o see s h a Uow overland flooding This shallow flooding is primarily con tained in the streets when a storm event excee d s th e sto rm drain capac it y" The two maj o r flow p a th s are g e n e rall y d esc ribed as follows: Beginning near th e int e r sec tio n ofN. King St reet and W 271h Avenu e t r ave lin g southeast t o the Sou th Platt e River on the east s id e o f Mil e Hi g h Stadiwn. Bcgitmin g ncar Irving Street and Speer Boulevard trave lin g southeast along Speer Boulevard to I-25 Proposed Capital Improvements: Drain age impro ve m e nt s in thi s basin are p rim a ril y recomme nd e d t o achi eve the minimwn perfonnance o bjecti ves as described in D e n ver s D rainage 2-year and 5-year systems f o r r es id e ntial and conune r cial areas respecti ve ly. To m ee t these reqttirements. most of the existing stotm drain network \ V iii n eed to be replaced These im provements can be pha sed i n s mall e r projects followi n g the completion of the major project comp o nents. Prop ose d capital improvements i nclude : September 20 1-J. Con struc tion of s t om1 dra in s in l ocal road s s ho w n t o i mprove interception of m ino r stOJm event nmoff and con veyance with in n e i g hborhood s Ins tallation offour new outfal l s und e r I -25 at N Bryant Str eet and 19\h Aven ue ; at N. B zyant Street a nd W 20th Avenue: at W 23r d Avenue and N. Alcott Str eet: and at N Zuni Street and W Jnstallation of major storm drain intercep t o r s connecting t o the I-25 outfalls Page 44

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Key Map Wheat Ridge e ., .. ;: .. u 0 : iii li E g. ::; a.' ::; 0 Vl 0 N "' 8 D g. 1 "- i e g e' 0 600 1.200 .?! Feet ;:: 1 inch equals 1,200 feet ( 4700-01 ) SloanS Lake For Detailed Hyd rology See Technical Appendix and Work Map 1-(j) z 0 (/) >-2 z UJ 1-z W27THAVE W 26TH AVE W 24TH AVE Cooper Lake ..... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Thalweg W 19TH AVE Proposed Storm Pipe UDFCD Study Recommendations X Proposed Pipe Disconnect -Legend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location (' Proposed Detention t-.J Basin Existing Basin 11 Potential Inundation L__.1 Area Planned Transit Line Existing Transit Line D City and County Boundar y ...... : Other Municipalities D Other Counties ( 0062-01 ) ( 4600 -01 ) \ Proposed Projects .... A 19TH AND 23RD AVENUE OUTFALL$: $3,443,117 .... B 20TH AVENUE COLLECTION SYSTEM: $5,613,592 .,.. C-20TH AVENUE OUTFALL: $10,086,949 _., D 24TH AVENUE COLLECTION SYSTEM: $10,840,435 .... E TH AVENUE COLLECTION SYSTEM: $12,433 ,948 .... F 7TH STREET OUTFALL: $11,435,254 .... G CENTRAL STREET COLLECTION AND OUTFALL SYSTEM : $6,850,621 ..., H UPPER 29TH AVENUE AND UPPER ZUNI COLLECTION SYSTEM: $8,581,140 Basin 0061-01 27th & Federal Denver Storm Drainage Master Plan Pag e 45

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D e n ve r Stonn Drain age Master Plan Basin 0061-02 (Highland) Existing System Description: The Highland collection system basin is l ocated in northwest D enver. The approximate boW1dari es of the basin are W 34th Avenue to the south. 1-70 on the nort h the South Platt e River t o the east and a varying edge on the west extending as far west as N P erry Street. The basin is comprised of approximate l y 1 909 acres (2.98 square mil es) of full y developed area. Th e basin ge n eraJ l y drain s from west to east and h as m u ltipl e outfa U s i nto the Sout h Platte River The basin i s co mp osed of a variety of l and u ses including residential parks commerc i a l and ind ustria l land uses. Much ofthe b asin is residential w ith commer cial areas primaril y lo cated along Federal B ou l evard, W 38th Avenue a nd the 1 -25 corrid or. Man y areas hav e mixed comm e r c i al/ retail space o n street come r s wit h gas sta t io n s co n venie n ce sto res and o th e r neig hborh ood retail outlets. The nortJ1 east corner of the b asin i s compose d of indu strial an d wareho u se u ses. Thi s area is general l y bound ed by 1-70 (nort h) and W 44t h Ave (south) and N. P ecos Street (west) and the R enn i ck Rail yard (east). Blueprint Denver s h ows ''Areas of C h ange in the vicinity ofW. 38th Avenue. just west of Federal B oulevar d N. Inca Street north ofW. 38' h Aven u e and W 44th Ave n ue just east of F ede r a l B ou l evard. Th e remainder of the basin is sl1ow n as being an A rea of Stabilit y" All drainage f r o m this basi n outfalls to the South Pl atte River. I11te r cepted sto nn water is discharged in over 5 separate st01m drainage outfalls whi ch cross under 1-25 ultim ately discharging into the South Platte Some of th e more major outfalls includ e: Do ub l e 8 x 8 bo x c ulvert and a twin 7.25' x 3 ,5' box culvert at W 34th Ave n ue and N Kalamath S t reet 60-inc h x 84-inc h pipe at W 381h Ave nu e and I25 24in c h stonn pip e crossing tmder 1-25 at Inca Street dtaitring a small l ocal b asi n j ust v.' est of 1 -25 A 36-inc h and a 30 -inch storm drain cross i ng under 1-25 just north of the P a rk Avenue overpass draining a small local basi n on the west side of 1-25 Drainage Deficiencies : Stonn drain infrastructu r e in this basin l1as u nd e r s i zed outfal l s. inco mpl ete n etwo r ks of sto nn drain l ate r a l s and Is primarily co mp osed o f brick and c l ay pipe systems w hi ch do not m ee t Denver s dr ainage criteria for s i ze and/or m aterial. Much of the system was pre v iousl y a part of a combined sewer s y stem wb.ich has since b een sep arated from the sanitary compo n ent. Th e Hi g hland B asin lies o n a r elat ive l y s t eep area on t h e s i de of th e So uth Platte Riv e r Valle y. As a r esu lt \Vater te n ds to m ove qldck l y through the basin and ge n eral l y does not prod u ce areas of severe ponding H owever there are five major flow paths wit hin the. overa ll bas in that do see overlan d flooding in1arg e r stonn eve nt s. TI1is shal lo w flooding i s primarily contained in t h e streets w h en a stonn eve nt excee d s the stonn drain capacity Th e five major flow path s identified as t h alwegs are generally described as follows: Along W. 4 7'h Aven u e from near N. Pecos Street .flowing cast toN_ J ason Street, then north eas t u n der 1-70 ru1d e nt eti n g the Globe v ill e Utal1 Junction (0059-0 l ) Basin B eg innin g near 461h Ave n ue eas t ofN, Jason Street flowing sou th betwee n N. Inca Street and the UPRR/BNSF railroads t owards theW. 38th Aven u e lLOderpass and l -25/38th Avenue/Park Avenue West int erc han ge. September 2014 B egin nin g at the int e r section ofW. 44th Avenue and N. Zuni Street flowing east in W. 44lh Avenue toN. Shoshone Street then southeast toN. Inca Street between W 361h and W 37t11 Avenues then east and tmdemeath 1-25 crossing the railroad. thence northeast through the B NS F railroad y ard. B eginning at the intersection ofW. 415 1 Avenue and N. Bryant Street, flowing so uth east and ultimately reaching the bank of stonn drain i nlets at W 34lh Avenue and N. Kal a m at h Street Beginning a t th e intersection ofW. 36th Avenue and N. Alcott Street tlowing northeast toW. 38t11 Avenue and N Tejon Street, t hen east on 38th Avenue toN. O sage Street and so uth eas t towards the bank of stom1 drai n inlets at W 34th Avenu e and N. Kala m ath Street. In g e neral much o f th e existi n g syste m is lUldersized and does not adeq u ately convey the 2-ycar or 5-y e a r design flows. The storm drain system a l o n g N. lnca Street (W83-3 33 A and W83333 B constructed from 1988 through 1994) was designed for th e 2-3/4 year event and was cons tru c t ed of concrete p i p e. howeve r the design frequenc y ide nti fied in t hi s stu d y indica t es the need for a 5-year syste m the r efo r e this syste m is undersized as welL The 2013 GlobevilleUtah .function Outfall Syst e m s Planning Study b y CHM2 Hill for the U DFCD. co nfirm ed that in larger sto nn events runoff from t h e S u n n ysi de Ne i g hbo rhoo d sou th of I-7 0 ca n l eave th e Highland Basin (006 1 -02) from south of 1-70 in the v icinity of J ason S treet and enter the Globeville Uta h Junction B asin (0059-0 I ). Th e trans-basin flow r ates s hown on th e facing pag e are from the Glob ev ille OSP not m odeli n g documented in th e T ec hn ica l Append ix. For purposes o f thi s Master Plan a I 00-yeat a lt ernative i s proposed for Basin 0061-02 to inter cept this runoff in the major storm and convey i t so uth to the South Pl atte Riv e r. This improvement would pre ve11t all flows from south ofl-70 from entering the GlobevilJe-Utah Junction (0059-0'1) Basin Propose d Capitallmprovements: Projec t s A-K Drainage improvements in this basin a r e primarily recomm e nded to achieve the minimwn performance objectives as described in D e n ver s Dr a ina ge Crit e ria Manual; 2-yea r a n d 5-y ear syste m s for r esi dential and comme r cial areas r espective l y and all owi n g str eets to co n vey runoff up to 12-inches deep in t h e gutte r in larger stot m eve n ts. To m eet th ese requir e m e nt s most o f th e exist in g stonn drain network will n eed to be re placed Th ese improvements can be ph ase d in smaller pr ojects following t h e completio n of the m'-\ior o u tfall project compone nt s. P roposed cap i tal improvements include: I nstalla tion of new outtalls under 1-25 at W 34th A venue ahd Lip an a nd Par k Avenue and 1-25_ Jnstallation of major storm drain interceptors connecting t o the 1-25 outfalls Construction of s t orm drains in l ocal roads shown t o imp rove interception of minor stonn event runoff and co n veyance wit hin n eig h bo rho ods Pag e 46

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Key Map 0 600 1,200 0 Rocky Mountain Lake IV) (.!) z IV) (.!) z > 0:: z For Detailed Hydrology See Technical Appendix and Work Map w > 0 0::: (.!) z 0 :::; m ...J <( 0:: w 0 w lL z z ( 0061-01 ) ..... Collection System ..... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe .... UDFCD Study Recommendations -W 33RDAVE IV) z 0 ...., w 1-z \ W32NDAVE z tn' P roposed Project s Argo Park 4AF NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. The trans basin flow rates are from the Globeville OSP. not modeling documented in the Technical Appendix. J 11 _. AW 34TH/35TH AVENUE COLLECTION SYSTEM: $8.428,352 B W 34TH AVE AND LIPAN ST OUTFALL: $9,238,206 C 40TH AVENUE AND FEDERAL COLLECTION SYSTEM: $13,502,327 _. D42ND AVENUE AND FEDERAL COLLECTION SYSTEM : $5,982,532 E W 46TH AVENUE COLLECTION SYSTEM: $4,819,774 _. FW 47TH AVENUE COLLECTION SYSTEM: $8,604,756 G CHAFFEE PARK INTERCEPTOR: $8,670,816 _. H FOX STREET OUTFALL: $8,233.456 I LOWER W 38TH AVENUE COLLECTION SYSTEM : $10,491,127 J LOWER INCA STREET COLLECTION SYSTEM UPGRADES: $8,191,813 K UPPER W 38TH AVENUE COLLECTION SYSTEM : $9,646,239 Legend Existing Storm Pipe r ProposedDetention -+-ExistingTransitline Basin 0061-02 -.J Basin Designed Storm Improvement Existing Surface Flow Existing Basin g City and County Boundary H i g hI a n d D Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 ,2ooreet Thalweg X Disconnect SignificantFioodingLocation -+--Planned Transit line Denver Storm Drainage Master Plan Page 47

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D e n ve r Stonn Drai n age Maste r Pla n Basin 0061-02 (Highland) (Alternative 100-Year Basin) Proposed 100 Year Alternative Capital Improvement s : Pro ject L : Northwes t Subarea lnte r ceptor St01m Drain The Jantlary 20 1 2 North wes t D enve r Sub-Ar ea Drainage and Tran sportation Study b y WH Pac ific includes a no det e ntion a l temative (Alte m ativc C) for a 1 00-yea r stonn drain syste m on the east sid e of th e basin Thi s im pro ve m e nt inclu des installation of 1 2 'x6 RCB, and 84 '' to 1 20'' RCP t hat gen eral l y follows J ason Street from West 4th Street to t h e South Pl atte Ri ve r. Thi s impro ve m e n t will preve nt a ll flows from enterin g the Gl o beviiLe Utah Junction (0059-0 1) Bas in Proposed 1 0-year impro ve m ents w ithin the Gl o bevill e Utah J u n ctio n (0059-0 I) B asin account f o r this I 00year alternative preve ntin g an y flows from tra ve lin g n o rth oflnterstate 70 o r cast oflnterstat e 25 September 201-/. P age 48

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K ey Map 0 600 1,200 0 -l -l w 0 -l z Rocky Mountain Lilke 1-(/) {!) z > tY 1-(/) {!) z 5 Q;: z w > 0 0: {!) z 1-(/) -l -l <( (.) tY z w 0 w lL z ( 0 0610 1 1 1-(/) z 0 lJ 1-z L egend \ W32NDAVE ln' (/) ...... Collection System Existing Storm Pipe f' -. Proposed Detention Proposed Storm Pipe ...... Boundary &----.l Basin For D e t a il e d Hy d rology See T ec hni cal A pp en dix and Work M ap t:t Topographic Basin ---UDFCD Study Designed Storm Improvement ..J' Boundary Recommendations Existing Basin 1 : 100-yr Sub-Collection --E x isting Surface Flow D Potential Inundation : Other Municipalities -+-Existing Transit Line D City and County Boundary ( 0 059-01 1 ) Prop ose d Pr o j ec t s NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. The trans-basin flow rates are from the Globeville OSP, not modeling documented in the Technical Appendix. '. .,.. L-NORTHWEST SUBAREA INTERCEPTOR STORM SEWER: $25,199,832 Bas i n 0061 -02 1 00yr Alternative Hi ghland Feet System Boundary X Proposed Pipe Area _____________________________________________ _______________ jr ______ s ig n ih c an t F Io o d in g L _oc_ a ti o n __________ _________________________________ P age 49

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D e nv e r Stonn Drainage Master Plan Basin 0062-01 / 4500-02 (Lower Platte Valley) Exi sting System Description: These two collection syste m basins combi n e d includ e a mi x of indu s trial. comm e rcial and residential land u ses. and includ e 2.856 tributar y acres (4.46 s q uare mi l es ) The basin i s fuJiy built-out with older neighborhood res identi a l in the upper reaches and commercia l in th e lower r e ach es Tili s basin includes Lower Dow11town. Coors Field. rail yards, and a munber of existin g resi d e nti a l neighborhoods It is c h aract erized b \' t e rra ce topograph y in the upper portion s of th e b asin and ve r y flat outfalls n ear th e South Platt e Ri vc r Ti1is co ndition results in inadvertent dete ntion near t h e basi n headwat e rs and s urcharge of stonn drains in lower reach es. Currentl y, most of th e drainage (nearly 75 % oftbe b asin) outfall s through o n e 8 J -inch storm pipe at 361 h Street. with a ppro x imat e l y 1 ,936 acres tribu ta ry t o thi s o n e o utfall. Th e exi s tin g pip e has approximate l y 476 cfs capacity. b u t the h y drology indicates the flow wi ll be o ve r 1 .000 cfs in a 2-ycar event, and 1 700 cfs in a 5-year event (des ign flow). There are opportunities for regional water qu a lity treatment off th e existing 81inch pip e ncar th e South Platt e o utfall since it curre ntl y can convey a rainfall (WQCV) over s uch a large devel o p e d basiJ1 a r ea. Drainage Deficiencies: The exis tin g drainage system has l ess than a 1-year capacity. R ainfall nmoff in excess of t h e storm drain capacity has a history ofponding in th e sump and flat areas Man y of th e exi sting storm drain s surcharge o ut th e manholes durin g l arge s torm even ts Major drainag e problems have been exp erie nced in this basin. particularl y north of Coors Fie ld During a major sto rm event. split flow conditions exist in d1e basin w h e reby stom1 runoff is and import e d out and into thi s basin For split flo w condition se e th e 3 1 t Street & 36'1 Stree t Outfall Study and Concept Desi g n R eport, December 20 1 2 b y Wi I son and C o mpan y. Potential Inunda t io n Areas: Several areas of potential immdation have been ide ntified witllin the bas in mos tl y in areas w h ere the streets becom e v e ry flat. The areas s urrounding the int e rsections of 36th Stree t/Blake Street. 31 $I Street /Blake Street. 32ncl Street l7'h Avenue /Lafayette Stree t 16th Ave nu e /Frank lin Street and 161n A ve nue / Clark so n Street have been idcnti fied as locations where l 00-year inundation depths could reach up to 3-feet in d e pth durin g a I 00year event. Proposed Capita l Improvements: This basin requi res impr ove m ents primaril y to the outfall since the l a teral network i s c urrentl y extensive in t hi s basin The o utfall s hould h ave 5-year capaci ty. whereas th e l ateral network through th e r esidential areas s hould have a 2-yea r capacity The e xi s tin g 81-inch outfall in 361h Stre e t is unders i zed and additional o utfall s are need e d to relieve the burden on th e existing pipe Constructing tvvo new outfalls in this ba si n will r educe the tribu t ary area of th e existing outfall. l11e Jr Stree t & 3rJ" Street Outfall Study and Concept D esig n Report, compl eted b y Wilson and Compan y in 20 investigated several outfall alte mati ves w ithin th e basin and the rcconun e nd a tion s from that r eport are reflec ted i n thi s Maste r Pl an. Thirtee n major drainage projects arc propose d for this bas in a s described below: September 20 I-I Project A : Marion Street S vstcmPhase I conne c t s to th e recently designed River North Ou tfall locat e d in Stre et. The Phase l ext e n sio n includ es a new I 02-inch pipe in Marion Stree t from 32nd A venu e t o 29'h Avenu e. The existing pipe \ Vill be cut and plugged to provide additional capacity in th e down strean1 syste m w h e r e the new pipe crosses th e exis tin g s t orm pip e Work o n thi s project should begin at the outfall and extend upward to improve the level o f drainag e service in th e basin Project B: Marion Stre e t SystemPhase 2 sto nn drain' ill continue up the basin wid1 a l 02-in c h to 90-tnch pip e in Downing Street to 2 1 s t A ve nu e. Project C: East 2 4th Avenue Svstem prov id es additional stonnwat e r collection for the propo se d trunk lin e in P roject B I t includes a 60-i n c h pip e in 24'h A ve nu e w ith additi onal lines extending up to 20th A ve nu e and Vine Street. This prqject also include s r eplac in g exis tin g s m al l pipes wit h 1 8-i nch dirunetcr pipe s to meet current drainage criteria. improve collection/conve yance and r e duc e maintenance probl e m s Project D : Citv P ark West Dra in age Improve m ents ext e nd s into the upper basin with an84-inch to 36 inc h diameter Thi s p roject a lso inc lu des r e p lacing s m all pipes w ith 18-in c h diam ete r pipes to meet curre n t drainag e cri t eria. improve collection /conveyance and reduc e maintenanc e problem s. Project E : East I t h Ave i mpro ve m e nt s includ e replacin g existing s mall pipes with 18-in c h diame t e r pip es t o meet current drainage criteria improve col lection/con veyance and reduc e maintenance problems. Pro ject F : 2 71h Street Int e rc eptorPh ase l includes max imi z ing th e us e of the existi n g I 08-i n c h pip e i n th e Coors Field Parking L ot. Currently, t h e tributary area t o the pipe i s onJ. 88 acres. The o u tfall ,.,ill ext e nd u p 271JJ Street t o Champa Street \ Vid1 a 96-in c h pip e P roject G : 27th Stre e t Inte rceptor-Phase 2 will continu e upstream in 271h Street from Champa Street to Washington Street and al o n g Washin!:,rton Stre e t t o 19'h A ve nu e wi th a 90-in c h t o a 72-in c h pipe Proj ect H : 27th Street InterceptorPhase 3 wi II c tend alo ng Clarkson Street from 19th Avenu e to 1 41h A ve nu e with a 60-inch pipe transitioning do' n t o s mall e r pip e up into the basin Thi s also iJlc ludes late rals in 16th Avenu e Proiect 1 : 2711' Street Interce pto r W a lnut/Mark e t L ateral Includes a new upsi zed pip e 11e tw o r k in Walnut/Market Street south of 27th Street. Proj ec t J : 27th Street Int e rc eptorChampa Lat e ral consi s t s of a new box and pipe network in Champa Street south of 2 71 h Street Project K: North Mari o n Street Lat e ral s propo ses t o replace the exi sting small stom1 drai n s east of Project A \\ ith 18-inch or larger pipes t o meet current drainage c rit e ria and reduce maintenance Project L: East 33rd Avenue L ateral s includes a sys t e m t o b al ance out the r emainde r of the basin tri butar y t o tbc existing outfall. A new 42-incb pip e at 33'd and Downing Street will disconnect the e xi sting pipe in H umboldt Street and con vey ru n off to t h e exi s ting 8 1i nch pipe in Downing Street. which i s b e in g r e l ive d with construc tio n of th e new o u t fall in 33r d Street. In a dditi o n existing s mall stonn drai n s are proposed to b e replaced with 18-inch pipes to meet curr ent drai n age c rit e ria and reduce maintenance P roject M : Grant Street Storm Drain collect s runoff from th e existing stonn drains in 9th and lOth Aven ues at Ogde n Street and delivers runoff in a 5-year even t to d10 l31h Avenue E xtension project in Basin 4600-0 J l11is prqject also inc l ud es up s izin g t h e exi s tin g s torm drain in Grant Street from I Oth to 1 3 th Ave nu e P age 50

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0 K ey Map [ 0061 -02 ] [ 0061 -01] 800 1,600 For D eta il e d Hydrology See T ec hni cal A p pend i x and Wor k M ap ..... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe ... UDFCD Study Recommendations [ 45000 1 ) L egend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location (' Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__.1 Area Planned Transit Line Existing Transit Line D City and County Boundary ( 450 0-04) [ 4600-02 ) Pr o posed Pr o j ec t s NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems. not proposed drainage improvements .... A MARION STREET SYSTEM PHASE 1 : $3,336,352 ...,. B MARION STREET SYSTEM PHASE 2:$8,878,818 .... D CITY PARK WEST DRAINAGE IMPOVEMENTS : $14.235,873 ..... E E 12TH AVE IMPROVEMENTS: $3,783.762 ..,. F27TH ST INTERCEPTOR PHASE 1 : $8,086,632 ..... G 27TH ST INTERCEPTOR PHASE 2:$7,924,292 .... H TH ST INTERCEPTOR PHASE 3: $4,452,452 .... 127TH ST INTERCEPTOR WALNUT/MARKET LATERAL: $1,988.101 ...,. J 27TH ST INTERCEPTORCHAMPA LATERAL: $4,477,254 ...,. K N MARION ST LATERALS : $2,422,884 .... LE 33RD AVE LATERALS :$10,260,820 ..,. MGRANT ST STORM DRAIN : $7,652,395 Basin 0062-01 & 4500-02 Lower Platte Valley and 36th & Downing

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D e n ve r Stonn Drain age M as t e r Plan Basin 0063-01 (Central Platte Valley) Existing System Description: Thi s c o lle c tion sys t e m b as i n consist s of a r eas drainin g t o th e right bank o f th e S ou t h Platt e River from Bayaud A ve nu e o n th e sout h t o Sp ee r Bo ulevar d / Ch erty Creek on the n o rth and as fa r eas t as L ogan St ree t Thi s b asin co n s i s t s o f 1 29 7 ac r es ( 2.03 s quar e mil es ) and includ es o l de r n eig hb o rho o d r esi d e n tia l in th e up pe r r eac h es eas t o f t h e r a ilr o ad trac k s an d S anta F e and c omm e r c i a l i n th e l owe r r eac h es All dr ainage from this b asin o utfal l s int o the Sou th Pla tt e Rive r [nt e r ce pt e d s t onmv a t e r i s d ischarge d via a t l eas t 32 s t o nn drain age outfalls w hich are c ompri se d mainl y of l oc al sto rm drain s from T-25 and adjace n t pro p erties. S o m e o f t h e exis tin g l arge r outfalls inclu de: B a y aud A ven u e o utfall i s 36i nch ( 5 4-in c h upstrea m) w ith 3 44 tribu tary acres 3 rd Aven u e outfall i s 5 4in ch with 214 tributary ac res 6tn A ve n ue outfall is 72 -in c h with 256 tribu tary ac r es 13th A ven u e outfall i s 4 2 -in c h w ith 119 tribut ary ac r es C o lfa x A ve n ue outfall i s 36-i n ch w ith 39 tribu tary acres Eli tch o utfrul is 48inc h with 4 4 t rib utar y ac r es Th e sto rm drain infr as tru cture cons i sts of a raudom n etwor k o f d.raills and late ral s D ra ina ge f ro m th e b asin i s c on s train e d b y th e e l evatio n o f th e S o uth Platte Rive r and l -25 whi. c h gen e rall y r e du ces ca paci ty and c reat es s ump or su r c h a rge co ndition s durin g major s t o rm events Th e r eac h adja ce nt to the So uth Platt e Rive r b e t ween 61 h A ve nu e and Ch erry C ree k was r e m ove d fr o m th e ri ve rin e floo dpl ai n b y LOMR Case No. 1 2 -08-04 74P, D ece mb e r 17.201 2 b ythe co m p l etio n ofth e S o u t h Platt e River R es t orat i o n impr ove m ents Drainage Deficiencies: Th e exis tin g drain age sys t e m s h ave capac it ies varying fr o m a !-year to a 5 year s t o tm eve nt. Rainfall runoff in exc ess of th e stor m drain cap a city h as a his t ory of p o ndin g w i t hin t he co mm e rci a l a nd in d u s trial areas against t h e railr o ad a nd 1-25 Local ize d p o ndin g occ ur s fre qu e n t l y a t W Ellswo rth Ave nu e an d N Lipat1 Stree t due t o to p ogra phi c cons train ts imp ose d b y t h e existing r a ilro a d and 1 -25 Th e basin d e lin eat i o n i s b ase d upon th e s t o nn drain n e t wo r k. Th e only s plit flow sit uat i o n in thi s b a sin w h e r e th e pip e flow contrave n es th e s ite to p ogr aph y i s a t t h e Eli tc h es s it e Runoff in excess of th e 16 x4 box culvert capa c i ty a t t h e P e p s i C e nt e r w ill flow fro m t h e Aurari a Calli pu s a nd t he P e p s i C en t e r are a n o rth wes t int o S i x F l a gs Elit c h Gard e n s Two m a j o r -eve nt FL0-2D a n alyses ide nti fy t h e P o t e nti al Tmmdatio n A r eas al o n g Broadway, fr o m Ala m eda A ve nu e to 5th Ave nu e and anot h e r at IOih A ve nu e and O sage S t r ee t. Th e result s wer e i n co rp ora t e d i nt o t h e M as t e r Pl an A t r an s -b as in flow o f 58 c f s fro m th e 4600 01 B asi n a t 1 olh A ve nu e an d O sage Str ee t was ide ntifi e d durin g a 1 0 0 year s t o rm eve nt. Proposed CapitaJ Improvements; Blueprint D e nver s h ows the m a j o ri ty ofth e b asiu (co mm e r cial are a s) a s Areas o f C hange" Onl y th e res id e ntial n e i g hb o rhood cas t o f the r ai lroa d tr ac k s b et\.vcc n A l ameda and 8th Ave n ue i s s hown as an Areas o f S tabil ity a re lative l y s mall are a ofthe ove rall b asi n Difficulties in cons tru c tin g addit io n a l or r e pl acement storm drains a r e th e crossing o f t h c r a ilroad an d 1 -25 C OOT' s V alley Highway -Logan t o 6d' Avenue RecQrd of D e cision (ROD) dated Jtm e 200 7 S ectio n 4 .9.1.4 St01mwat e r Dr ainage n ote d that D e n ver s Storm Drainage M a s ter Plan a nd subseque nt dr ainage impr ove m e n ts s hould b e co n side r e d w it h eac h p h ase o f final design for t h e Valley Highwa y Pr o j ec t September 20 1-J Pro jec t A : W es t L3!h A ve nu e Outfal l Thi s proj ect includ es r e pla c ing th e existing 42 -in c h o u tfull w ith a new 66-in c h pipe t o pr ovide a 5 yea r l eve l o f serv i ce. The e nl arge m ent of th e exis tin g syste m is carri e d u p th e s t01m drains alon g 13th Ave nue. Th e 13111 Ave nu e o utfall i s s h o"Vvn w ith a l ate ral exte n s i o n o f a 54 -inch s t o rm dra in furth e r int o th e su bb asin fo r connection b y futur e red eve l o pm ent Pro tec t B : W es t 7lh Aven ue Ou t f aJI Th e ex i s tin g 72in c h s t o rm dr ain in 7th Aven u e mu s t b e up s i ze d t o a 90-inc h pip e t o provid e a m i nim um 5 -ycar l eve l of serv i ce An exis tin g con s tri c tion occurs w h e r e a 60-inc h pip e w i t h 0 .6 1 % s l o p e c onn ec t s dow n s tr ea m t o a 4 2 -in c h and 48-i n c h pip e at 0 6 1 %. Thi s intenned iate r eac h of pipe b e t wee n Qu i vas a n d T e j o n s h o uld be r eplace d w ith a lar ge r pipe ( 7 8 -in c h ) f o r 5 year cap ac i ty Proj ec t Wes t B ava ud Avenu e Th e ex i s tin g sys t e m has less tha n a 1-yea r event ca p ac ity. The Bay aud A ve nu e outfa ll con sis tin g of a 5 4-in c h p i p e i s prop ose d f o r r eplace m e nt with an 8 4-in c h pip e fo r a 5 year sys t e m A t G al a p ago, the pro p ose d pip e jog s o ve r to Ell sw01t h Aven ue to pr ese r ve th e existi n g tnm k sys t e m u p stream a nd to L ogan w ith a lat e r a l CA'tcndin g so uth inN Lin c oln S t reet t o p r ovide addit io n a l stotm con veyance in t hi s a r ea. Pr o j ec t D : West Ell swort h A ve n ue A s h o rt 24-inc h s t o rm drain o ut fall i n Ell sworth under 1 -25 s h o uld b e r ep l ace d wi th a 54-inc h pip e t o pro vide 5-year cap acity, a n d cJiminate fr e qu e n t p ondin g at E1lswo rth an d Lipan ca u se d b y bloc k age o f the run off by t h e rai lroad and I25. Pro jec t E: W est Mulb c rr v Pla ce A new 4 8 x72 box culve rt o utfall i s pr opose d in Mul be rry Place. This 60 acre area i s c u rre ntl y serve d b y 15 an d outfu!Ls R e d eve l o pm e nt o f t h e a rea w i Il p r o mpt th e co n s tr uc ti o n o f a n ew outfall, Pro tec t F : W es t 3rd A ve nu e Outfall A new 7 8 -in c h outfall is p ropose d to replace th e e x isting 60-in c h o utfall i n 3ra Avenue t o achieve a .5-ye a r l eve l o f serv ic e Proj ec t G : W es t C o l fax Aven u e Impro ve m e n ts 1 8 -in c h up g ra des and r e p l a ce m e n t o f an exis tin g 36 i n c h pip e w ith a new 60-in c b pi p e i s p ro p ose d in thi s ge n e r a l area P age 52

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Key Map 0 600 1,200 ,.,.. ............ .... _,. .. -..... ..,.,_ ..... # .,.. ...... _, --........ ... *.; .-Y _. --11111111 For Detailed Hyd rolog y See T echn i cal Appendix and Work Map ...... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe UDFCD Study Recommendations ____ ... _.. ....... ---..... Cher::t -.- ----( 4600-01 ) ( 0064-02 ] ) ... ; NOTE: Trans basin nows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvem ents. ( 5000-01 ] I ......... .. .... ..... ... ..... BW 7TH AVE OUTFALL: $16,345,116 C W BAYAUD AVE OUTFALL: $23,568,746 D W ELLSWORTH AVE OUTFALL: $2,424 040 E W MULBERRY PL OUTFALL: $6,795 177 G W COLFAX AVE IMPROVEMENTS: $3,670 189 Existing r --Proposed Detention -+-Existing Transit Line Basin 0 0 6 3 -0 1 -.J Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatlon g City and County Boundary centra I pI a tt e v a II e y --Existing Surface Flow L__J : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 ,2ooreet Thalweg X Disconnect SignificantFioodingLocation -+--Planned Transit line Denver Storm Drainage Master Plan Page 53

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D e nv e r Stonn Drainag e Maste r Plan Basin 0064-01 (1st & Federal) Existing Syst .em Descri ption: This collection system basin is tributary to Weir Gulch and the South Platte River b y topograph y a nd pipe network I n general. thi s basin i s located south of Weir Gulch The basin consists of279 acres (0.44 square miles) and includes resid en tial in the upper r eaches and industriaVcomrn ercia l in the lower reaches Much of the indu s trial land i s wi thin the c urrent South Platt e Rive r floodp lain Int e rc e pted stonmv ater is discharged via 6 storm drainage outfalls into t h e South Pl a tt e River. The outfalls i t1clud e : South Platte Ri ver Yuma Street outfall is 21-inch forlocal drain age 5'h Avenue outfaU is 42-inch wi th 172 tributary acres 6' h Avenue 42-iuch outfall for 74 tributary ac r es 6' h Avenue 15-iuch outfaU for local drainage 7' h Avenue 36-iuch outfaU glh Avenue 24-iuch outfaU The stonn drain infrastmcturc consists of a ra ndom netwo r k of dmin s and laterals in the low reaches and coll ectors in th e residential reaches. The condition and capacity of the existi11g in lets is unknown at thi s tim e Blueprint Denver shows the Federal Boul evard subject to change along with some ofth e commercial and industrial area adjacent to t he South Pl atte River. The residentia l neighborhoods are shown as Areas of Stability" in Blueprint Denver Drainage Deficiencies: Significant portions of Basin 0064-01 arc within the South Platte River regulator y floodplain including subbasins I 0 20, and 32 The areas in th e South Platt e Ri ver floodpl ain have capacity for t h e 2-year stom1 eve nt although this area should have a 5-year level of service by land use criteria. Proposed Capital Improveme nts: Propo sed South Platt e Ri ve r channel improvements from W 141h Avenue toW. 81h A venue vvill remove much of the d evelop m ent in this basin from th e regulatory fl oodp l ain The lower reaches ofWeir Gulch have been imp rove d to convey d r ainage duri n g the l 00-yea r event. No major dt:ainagc complaints have been reported in these basins o ut side the regulatory floodplains due to the r e lati vel y steep g r adient toward the r ece iving drainag eways and lack .of s ump s or flat areas. Th is b as in generall y m eets D enver drainage crite ria. The roads and drainage pipe convey t h e 2-year stotm eve nt in rcsid e nt1al areas and 5-year stonn event in th e comm erci al!industlial areas Most of t h e capital improvements proposed in D envers 1 989 M aster Plan have. been constructed This area has been improved b y construction of diversion facilities to Weir Gulch impl e m e nted s inc e the 1 989 plan September 201-1 A difficulty in constmctiug additional or replacement storm drain outfalls is the presence of the M e tr o Sanitary Sewer along the west bank of the South Platt e Rive r Otherwis e railroad t r acks and the int ersta t e are l ocate d on the o ppo s it e bank of the South Platt e and t h e r e are r e lati ve l y few obstructions for new s t o rm pipe in thi s basin. Propo se d projects include: Proiect A: West 3'd A venue Outfall Stonn drain l aterals are extende d further into t h e basi n to reduce srrcc t flo oding Stom1 pipes smaller than 18-inch have been upgraded to 18-in c h per current criteria ProJect B : West gm Avenue Outfall A new 3-foo t x 6-foot bo x culvert outfal l i s prop ose d i n 81h Avenue. Project C West 5111 Avenue Outfall A new 4-foot x l 0-foot box culvert otttfall is proposed in 51h A ven u e to better serve properties in the current South Platte River floodplain. A1112-inch and 1 5-inc h collector stom1 drains do not meet curren t drain age c riteria and h ave b ee n proposed for r e placement w ith 1 8-inch pipes Page 54

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K ey M ap 0 600 1,200 For D e tail e d Hyd rolog y See T ec hni cal App e ndix an d Work M ap ---' I [ 4 8 000 1 1 .-. Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe --UDFCD Study Recommendations Barnum Park Lake i ..... L egend Existing Storm Pipe 1-(/) a:: ::::> (.) w 0 Design e d Storm Improvement --E x isting Surface Flow Significant Flooding Location ;- Proposed Detention '--'Basin Existing Basin 11 Potential Inundation L.___J Area Planned Transit Line Existing Transit Line D City and County Boundary \ \ \ \ NOTE: Trans basin flows shown with a heav y black arrow are based on e x isting s t orm drain systems, not proposed drainage impro v ements. \ \ \ ( 4 6 0 0 -0 1 1 \. \<;;} ....:. \ 0 "& '! A-W 3RD AVE OUTFALL: $498,726 B-W 8TH AVE OUTF ALL: $2,071,019 Basin 0064-01 1st & Federal

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D e nver Stonn Drain age Master Plan Basin 0064-02 (Valverde) Existing Syst em Description: This collection sys tem basin drains to the South Platte River between 4'11 A venue on the north and Sanderson Gulch on the south. The wes t ern boluldarv of the basin is Morrison R oad The basin consists of L6 94 acres (2.65 square miles) Much ofth e upper is comprised of residential neighborhoods while t h e lower portion i s m ostl y com m ercial/ industrial along the South P latte River. An existing detention basin is located in West-Bar-Val-Wood P a rk located at W Bayaud Avenue a nd S. Tejon Street. Improvem e n ts h ave b ee n con st m ctcd along Mississippi Avenue, w hi c h convey 310 cfs, in t h e minor stom1 to Sanderson The improvements effectivel y remove almost all the Huston L ake are a from this basin when consideri n g th e minor stom1 events. In the major stonn a 100-year runoff of 1 ,026 cfs is imported into this basin via Mississippi Gulch located east ofS. P ecos and W Mosier Pl ace. The 2013 Sanderson Gulch Major Drainageway Plan and Flood Ha zard A rea Delineation b y M atrix Design Gro up f o r the U DFCD, evaluated a conveyance syste m to collect and convey t h e 100-year flows t o Sand e rson Gulch The storm drain infrastructure consists of a network oftmnk lines and l ate ral s includin g fifteen o u tfalls. D rainage from t h e basin is constrained b y the South Platte River floodplain, which parallels the west side of t h e river throughout the basin and has m.inim a l topogr aphic relief. BluePrint D en ver s hows Federal Boul evard Alameda A venue and Morrison R oad to c h ange along with some of the commercial/i ndu strial areas adjacent to the South Pl atte Riv er. Currentl y a significant p ortion of t h e drainage basin (55 % of the tributary area) out falls through a 9-foo t x cul vert at W 4th Avenue and VaiJejo Street. Desi g n point 1 1 50 s hows that 931 acres a r e tributary to tl1is one o utfall. Drainage Deficiencie s: The existing pipe s y stem that outfalls into the South Platte a long Vall ejo Street is undersized G e neraU y the lower portion of th e s y s t e m i s located in th e South Platte floodpl a in w hi c h i s r elative l y flat for drainage purposes. The 9-foo t x 4 Yz-foot box c ul vert i s deficient d u e t o the minimal 0. 19% slope. The syst e m can convey th e 2-year event in some areas but not in oth ers. A 5-year design criteria s hould b e set for t his indu stria l area. The svstem in Dakota Avenu e b e low Federal Boulevard will convey less t h an a one-year event. Storm drains the commerci al areas of Federal Boulevard s h o uld b e s i zed for a 5-year even t acco rdin g to D e n ve r s stonn drainage criteria Localized drainage probl e m s occur in the industrial areas along th e river mostl y due to relat i ve l y flat grades. The areas north and south of Vanderbilt Park have been identified ""1th drainage probl e m s as well as p rop e rtie s a l o n g S Jason Str eet. Proposed C apital Improvements: This basin requires improve ments primaril y to tl1e outfall s ince tl1e l ateral network i s currently e:-.1:ensive in tb.is basin Th e outfal l should h ave 5-year capacity, whereas th e late ral network through the residential areas shoul d have a 2-yea r capacity September 201-/. Ptoject A: 18-Inch Upgrades This project upsizes various pipes to t h e Citys 18-inch minimum diameter pipe Project B : S Huron St. Ou tfall A 42-inch out fall is proposed along Huron Street to serve comm ercial properties alon g tl1 e Sou th Platte River In th e so uthern portion of the. basin. Pr ojec t C W. Alameda Ave Outfall A nev v dual system in w Alameda A ven u e and w Byers Drive: from the South Platte River to s Tejon Street is p roposed to prov id e improved drainage in this basin Upstrea m of Tejon a 6-foot x 6-foo t RCB 84-in c h R C P i s p roposed alon g A lameda Avenue to r e lieve the existing Vallejo Stree t Syste m Th e new p1pe v v i II r eceive a portion of t h e flo w fro m th e Alameda/ Alcott intersection w hil e the remainder of the flow wi II be conveyed b y the existin g Vall ejo Street outfall I mprovements are a lso proposed in Alcott Street be t wee n Alameda and Virginia Avenues. A proposed 60-in c h pipe along Virginia Avenu e w ill relieve the existin g system in Dakota Avenue b y providing additiona l con veyance to se rve subbasins 50, 60, 70 and 90. The i;np r ovements extend west of Federal B oulevard and then a long Fede r a l Boulevard (or the a lley west of Federal) to provide sto rmwatcr interceptio n for F ederal Boulevard, Pr ojec t D : W Arizona Ave. Outfall A 54-inch o u tfall is proposed along Hw-on Stre e t t o serve commercial properties along the South P latte River in the so uthern porti o n oftbe basin Project E : W. T ennessee Ave Outfall A 42-in c h outfall is proposed along Huron Street ncar V
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e K ey M ap Lakewood i ;' ... ..; iii NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems. not proposed drainage improvements. 0 750 1,500 For D e t a il e d Hy d rology See T ec h ni cal App e ndix and Wor k M a p ., I ,./ [ 4 900 0 1 1 -,,A ..... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe UDFCD Study Recommendations -Barnum Park Lake Barnum Park W K ENTUCKY AV E 0 al L egend Exi sting Storm Pipe Designed Storm Improvement -E x isting Surface Flow r' -' Proposed Detention -.J Basin Existing Basin .. Gutcl> 'f -+-Existing Transit Line D Ci t y and County Boundary .. ... 11 Potential Inundation : Other Municipalities P roposed P rojec t s __. A18" UPGRADES: $ 1 ,029,604 .... BS HURON ST OUTFALL: $820 955 __. C W ALAMEDA AVE OUTFALL: $20,950 128 .... D W ARI ZONA A V E OUTFALL: $3, 4 68,000 ..,.. E W TENNESSEE AVE OUTFALL: $3, 027,546 Basin 0064-02 Valverde Feet Proposed Pipe L__J Area _____________________________ __________ jf ___ s ig n ir ic a nt F Ioo __ d in g L oc a tio n ________ P Ia n n e d T ra n sit L in e __ ____________________ P age 57

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D e n ve r Storm Drain age M aste r Plan Basin 0065-01 (Ruby Hill) Existing System De sctiption : The R u b y Hi ll colle ctio n system ba s in i s bounded b etwee n F e d e r a l Bo u levard and the South Platte Rive r and generall y between Colorado Avenue and Ilif f Avenue Rub y Hill Park i s l ocate d along the South Platt e River in the n ort h ern portion of thi s b as in. north of J ewell Avenue. A Power Plaut is l ocate d in the so uth ern portion oftl1e basin along th e South Platt e River. Approxjmat e l y 20% of the basin i s locate d within th e bo u ndari es of Eng lewood (soutl1 of Evans bet\veen Ztmi and P ecos) and the r emainde r is in D e n ve r The R u b y Hill drainag e basin i s a ppr oximately 1 25 square miles in size and i s fu ll y d eve lop e d with r es id ential and indu s trial properties in the upp e r r eac hes and indu s tri al properties in the lowe r r eaches along th e banks o f the South Pl atte River. The b asin is relati ve l y stee p with Evans Ave nu e gen e rall y b eing t h e low point (thalweg) o f th e drainag e basin The Evans sys t e m outfalls v ia a 72in c h pipe to the Sot tth Platt e Riv e r Oth e r o ut:fulls ih th e basi t 1 includ e a 36-in c h pip e in Warr e n a 4 8inchx72-in c h RCBC in Iliff and oth e r s mall local o utfal1s. Drainage Deficiencie s: Th e exis tin g drai11age syste m has capacity to convey less than the 5-year storm event wit hin Evans A venue an d J ewe ll Avenue. A small strip of Potential inu ndation areas occur w ithin ba s in s 300, 310 and 320. in a commercial area. w h e r e the railroad embankment blocks the tlow pat h to the So uth Platt e River The Pot e ntial Immdation Area is imme diatel y adjacent to the railroad track s and i s t oo thin to show o n the a dj o inin g map at this scak l11e flat topography al ong th e South Pl atte Rjve r m akes it di fficult to ade qua t e l y drain tl1e lo we r p o1tio n oftl1is basin Oth e r probl e m areas include: Basin s 220. 230 240, 250 and 260 wh i c h drain an ind ustrial/r eside ntial area should be size d for the 5year Th e 5year flow rate is 399 cfs TI1e e x isting 36-i nc h storm drain capacity canno t handle eve n t h e 2 year event of 221 c fs. Propo se d Capital Improvement s: Drainage improvements in this basin s hould b e v iewed primarily to achieve the minimum o bjectives for r esiden t ial and commercial areas (2-and 5 year sys t e m capac i ties) esta bli s h e d for the City and Cotmty of D e n ver. Although this basin has not been ide ntifi e d b y Blueprint Denver as a sig nificant area of change red eve lopm ent of thi s area could pro vide au opportunity to construct the propo se d fucilities. T wo exis tin g d e t e ntion ba sins are locat e d w ith i n the u p per p01ti o n of th e b asin. The d ete n tion bas i ns ar:e l ocate d nort h of W E vans Ave b e t wee n S Val lejo Stre e t and S. Tcjo11 Stre e t. The two existing d e t e ntion basins are s mall and are not mod e le d in the h y drolo g i c anal ysis No improvements to these facilities are propo sed The propo se d stOJm d rainage impro veme n ts are summari zed belo w : Project A: 1 8in c h Upgrades This project i n c ludes up s i z in g an exis t i n g 1 5 -inch stom1 drain L ateral loca ted within t h e alley between Kalan1ath and Jas o n Street t o an 1 8-inch storm drain. Sept e mber 201-/. Project B : S. Lipan St. Ou1fall Construct a new outtall to the South Platt e River inS. Lipan Str eet. TI1is new system w ill b e b e tween J ewe ll Avenue and Evans Avenue and ext end west in Evans Avenue to Navajo Street. Thi s new outfall w ill convey the 5-year s t o rm event from Propo se d Project s C D l and D 2 to th e South Platte Ri ve r. Proiect C S. Pecos a'lld W. iliff Impro ve m e nt s Constmct a new 5-year stotm drain to collect and convey s torm flows along the w est side of th e Burlin gto n Northern and Santa F e Railroad and arotmd the comme r c ial site a long South Pe{;OS Street t o Proposed Proj ect Bin Evans Avenue Pro jec t Dl: W. E v an s Avenue Improvements Up size th e existing storm drain in Evans Avenue b etwee n S Navajo Stree t and S. T ejo n Street to convey th e flo ws from P ro po se d Project 0 2 to Proposed Project B Project D2: W Evan s Ave. Extension Up s ize th e existing s tonn drain fac ility to a 5 -year capa c ity w ithin Evans Avenue f r o m th e exi s tin g d e t e ntion basin a t W. Pa c ifi c Pl ace to S Clay Stre et. Upsizc late ral s inS. Clay S tree t and S Z uni Street bet\;veen W E vans A ve nu e and W. W arre n A venue. Upsize the. culvert under W Asbuty Avenue b etween th e two smal l dete nti o n basins P age 58

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K ey Map a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. 0 600 1,200 For Detailed Hydrology See T ec hni cal Appendix and Work Map [ 5100-01 1 .... Collection System ...... Boundary 1-1 Topographic Basin Proposed Storm Pipe --UDFCD Study Recommendations -West fl. ----- arvard Gulch ....... ___ Arapahoe County ..... ..... .. ,. ..... \ I W EVANS AVE Arapahoe County [ 5200-02 1 ... BS LIPAN ST OUTFALL: $5,004,361 __. C S PECOS STAND W ILIFF IMPROVEMENTS: $3, 858,214 ... D1-W EVANS AVE IMPROVEMENTS :$2 803,514 .,.. D2W EVANS AVE EXTENSION: $4,082 154 L egend Exi sting Storm Pipe r --. Proposed Detention -+Existing Transit Line Basin 0 0 6 5 -0 1 Basin Existing Basin P City and County Boundary R U by H i II 11 Potential Inundation : Other Municipalities Feet Proposed Pipe L__J Area _____________________________ ___ D is c o nn e c t __________ ___ s ig n ir ic a nt F Ioo __ d in g L oc a tio n ________ P Ia n n e d T ra n sit L in e __ ____________________ "' Boundary Designed Storm Improvement -Existing Surface Flow Page 59

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D e n ve r Stonn Drain age Mast e r Plan Basin 0065-02 (Dartmouth) Existing System Description : The Dartm o uth Collection S ys tem Basin borders West Harvard Gulch Basin directly to th e south. TI1e Dartmoutl1 basin is bounded bet\ ee n F e deral Boul ev ard and th e South Platt e Rive r and generally between Amherst an d Hampden Avenues. Most of th e basin i s locat e d w ithin the bound a ri es of Englewood and only a ppro x imat e l y 30% oftl1e basin is in Den ve r D e n ve r's portio n includ es th e upp e r s t eep r eac h es n ortl1 ofW. Dartmouth A venue b e t wee n F e d era1 Boul ev ard and Zuni Str eet, and an industrial comp lex l ocated along t h e banks of th e South Platt e River north o f Dartmouth Avenue. Th e D a rtmouth collection system basin is approximately 0.76 s quare miles in size and is fully developed with re s id ential prop erties in th e upper r eac h es and industrial prop erties in the lowe r r eac h es al o n g t h e banks of the South Platt e Ri ve r Land u se mix in the basin i s about 1 /3 r eside ntial and 2/3 commercial and ind ustriaL Th e basin i s r e lat ive l y s t ee p w ith Dartmouth Avenue gen e rall y b eing th e low poi nt (thalweg) o f th e drainage basin No o utfall pipes in thi s basin a r e shown in the D e nver GIS databas e since tb e o utfall for tbis basin i s in Englewood Drainage Deficiencies: Curr e ntl y this basin drains east to Eng l ewoo d s stonn draina ge system w hich drains jnto the Sou th Platt e River. Th e 5-year flo w rate i s 424 cts. Th e exis ting Englewood syste m ran ges in size from a 42-inch pip e t o 73-inchx55-inch e llipt ica l pip e Th e r e is not s uffici e nt data to d e t e rmin e i f the exi sting Engl ewoo d pip e i s sufficient to convey th e 5-year storm event. No future impr ove m ents will b e propos e d outside of the C ity and County o f D e n ve r Proposed Capital Improvements: Proj ec t A: S. Brvan t Street Improvem e nt Onl y a small improv e m e nt is recommended al o ng South B1yant Stre e t fr o m Dartmouth A ve nu e to and west in Comell Avenue A 24 -inch 2 -year capacity stom1 drai11 i s propo sed September 20 1-f Pag e 60

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0 Key Map Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. 600 1,200 Fo r D eta iled Hydrology See T ec hni cal Appendix and Work Ma p 0 ::; al : I . . . . : 1 ...... Collection System ...... Boundary : ... : l Proposed Storm Pipe 1(/) a::: -W AMHERST AVE GIRARD AVE [ 0067-01 ) L egen d West H. -----.... Gulch -......... Existing Storm Pipe (' -' Proposed Detention '----' Basin .... [ 0065-01 ) -+-Existing Transit Line D City and County Boundary -eUDFCD Study Designed Storm Improvement Existing Basin I" 1 Topographic Basin Recommendations '"Boundary Existing Surface Flow 11 Potential Inundation : Other Municipalities Englewood Propose d Projects .,. A-S BRYANT ST IMPROVEMENTS: $492,604 Basin 0065-02 Dartmouth Feet Proposed Pipe L__J Area ___________________________________________ _____________ x ____ o is c o nn e c t _______________ ____ s ig n ir ic a nt F Ioo ___ d in g L oc a tio n ____________ P Ia n n e d T ra n sit L in e ___ ______________________________ P age 61

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D e n ve r Stonn D ra in age Master Plan Basin 0067-01 (College View) Existing System Description : The College View Collection System B as in has a total drainage area of approximatel y 1 .29 s q uare mil es. This basin flows east through D e n ve r and Littleton to it s con flu e n ce th e So uth Platt e River. Th e lower portion i s o ut s id e the Cit y and Count y of D e n ve r a nd was not s tudi e d The basin is c urr ent l y full y d eve lop e d wit h th e ex c e ption of a few scatt e r e d vacan t l ots including r eside nt ial, comme rcial and indus tri a l areas Drainage Defic.iencies: The e ntir e storm drain syste m '"vithin th e College View B asin is ade qu a t el y size d tor the 2-yea r s torm eve nt Howev e r th e stmm d rain syste m shou ld h ave 5-yea r capacit y du e to the comme r cial a r eas through th e n e ighborhood M uc h of the r es id e ntial area along W est Quin cy A venue does not h ave an y stom1 drain s ys tem and w ould b e n e fit fr o m a n ew lat e ral. Proposed Capital Improvements: T\ major stmm drain proj ects have been proposed in thi s b asin to increase th e level of serv ic e from a 2year ca pacit y t o a 5-year capacity Project A: S Quitm a n Street Impr oveme nt s A oe\ ; v 1 8 -in ch to 24 -inch sto nu drain from W. Quinn Pla ce toW. Stanford Avenue and S Quitman St ree t i s proposed Pr o j ec t B : W es t Union Ave nu e Impro ve m e nt s The exis tin g stm m drain system along West U ni o n Av e nu e does not meet th e minimum requir e d performance o bjecti ves fo r a 5 year stom1 drain Ups i zing th e ex i s ting s t orm dra in syste m t o a 4 2 -inch p ipe w ill satisfy t hi s requirement. Diffi culties i n co n st ru c tin g a n ew o utfall sys t e m for this bas jn would includ e coordinatio n w ith d ow n stream mun ic ipaliti es a t t h e two o utfaJll oca ti o n s Lowell Boulevard and F ederal B o ul evar d. Agr ee m en t s should be in plac e before a n y designs are "Consid ered September 201-/. P age 62

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0 Key Map Fort Logan Lateral 600 1,200 Marston Reservoir [ 0067-031 Fo r Detai l ed Hydrology See T ec h n i cal Append i x and Work Map ( 5500-01 1 WQUINCYAVE Arapahoe County Bow Mar .... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe UDFCD Study Recommendations ( 5500-01 1 ... ...... . . .. . .. .... ........... Englewood ..... P roposed P rojec t s ..,. A S QUITMAN ST IMPROVEMENTS: $1,612,118 ... B-W UNION AVE IMPROVEMENTS: $1,829,587 Existing ... --. Proposed Detention -+Existing Transit Line Basin 0 0 6 7 -0 1 -' Basin Designed Storm Improvement Existing Basin g City and County Boundary c 0 II e g e View -Existing Surface Flow c:::J Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 ,2ooreet Thalweg X Disconnect SignificantFioodingLocation -+PlannedTransitline Denver Storm Drainage Master Plan Page 63

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D e n ve r Storm D ra in age M as t e r Pla n Basin 0067-02 (West Belleview) E x isting Syst em Description: The W es t B elleview C ollectio n S ys t e m B as in h as a t o t a l dr a in age are a of ap p roxi m ate l y 4.21 s quare mil es. 'TI1is b as in flows eas t thro u g h D e n ve r a n d Littl e t o n to its con flu e n ce wi t h th e So u t h Platte R iver. Th e lowe r p o rti o n ofthis b asin i s o ut si d e th e City a nd Co u nty o f D e n ve r an d was not s tudi e d The b as in i s c urr e ntl y fuJJy d eve l o p e d w ith th e exce pti o n of a few scatte r e d vaca nt l o t s inclu din g r es id e n .tia l co mm e r c i a l and indu strial are a s. Drainage Deficiencie s : The existing d eve l opment in th ese b asins i s relatively n ew G ra nt Ranc h within B asin 0067-02 h as b ee n full y d eve l ope d a nd the s t onn drain a ppear s to be a d equa t e in th is a r e a TI1e drainage b asins t o th e n o rth a l o n g W B elleview Ave nu e an d "'rithin B as in 0067 02 h ave n o exis tin g stom1 d rain in D e n ver s GIS d a t aba se. Proposed Capital Improvements: P ro j ect A: W G ra nd Aven u e Im prove m e n ts Th e exis tin g r esi d e ntial n eig hb orhoo d a l o n g W Gra nd A ve nu e curre ntl y d oes not h ave any s t om1 d r ains A 2 year cap ac i ty s t o rm d rain sys t e m i s prop ose d a l o n g W Grand A ve nu e and wilJ com 1 ect t o Eng l ewood's sto rm drain sys t e m a t W Grand Avenue a n d S Mead e S t r ee t September 20 1-f P age 6 4

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e I 0 : la !! E g. :; I Q. ::; 0 Vl I "' 8 D g. 1 "-. I e g e' .?! ;:;: Key Map ....... .......... .,..------' I I =\ 0 \ GrantB Reservoir 750 1,500 Feet 1 inch equals 1 ,500 feet 0 Marston Reservoir [ 0067-03] Bowles Reservoir No. 1 GraniC Reservoir For Detailed Hydrology See T ec hnica l Appendix and Work Map ..... Collection System ...... Boundary 1-1 Topographic Basin '-...l Boundary Thalweg Proposed Storm Pipe ... UDFCD Study Recommendations X Proposed Pipe Disconnect Arapahoe County L egend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location (' -- Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L.__J Area -+-Planned Transit Line W TAN F ORAN DR -+-Existing Transit Line D City and County Boundary .. ... : Other Municipalities D Other Counties Sheridan ....... .... Propose d Proje c t s _.. A-W GRAND AVE IMPROVEMENTS: $2,311,003 Basin 0067-02 West Belleview Denver Storm Drainage Master Plan Page 65

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D e n ve r Stonn Drain age Master Plan Basin 0067-03 (Marston Lake) Existing Syst em Description: The M arston L ake Collection System Basin h as a tot a l drainage area of approximately 1.06 square mil es Thi s basin Is within Denver aJ1d has no o u tlet. A 1 2 -foot bjgh bem1 surtoLmds the reservoir. whic h i s owned and operated by D enver Water for potable water storage and keeps stor m water from entering or leaving. A smal l p01t io n of Mar sto n R eservoir does includ e a smal l resid ential area wit h no outlet. Drainage Deficiencies: No drainage deficiencies are identified at this time Propo se d Capital Improvement s: No improvements are proposed September 2 0 Pag e 66

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Key Map Jefferson County uwe Lake Henry .... .......... ........ _.....__ --:: .. ...... --...... .......... ____ ..... "11111 .. .. .. .. .. Jefferson Lakewood \ t .. /"""-I I .\ \ [ 5901-01 ) Bowles Reservoir No. 1 Grant C Reservoir [ 5500-04 ) Fort Logan Lateral ;- Proposed Detention '----'Basin Existing Basin 11 Potential Inundation L__J Area Planned Transit Line Jefferson County Existing Transit Line D City and County Boundary ...... : Other Municipalities D Other Counties .. Arapahoe County Bow Mar [ 0067-02 ) Bowles Lake . .. . . .. ...... [ 0067 -01 ) Littleton Basin 0067-03 Marston Lake Denver Storm Drainage Master Plan Pag e 67

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D e nver Stonn Drain age Maste r Plan Basin 3501-01 (West Fork Second Creek) Existing Syst .em Description: The West Fork of Second Creek i s loca ted aJong th e southern boundary of DIA w ithin th e City and County of D e n ve r and drain s about 3.45 square miles of area t o t11e main branch of Seco nd Creek. West Fotk Second Creek flows across P efia B oulevard at tbe 90 b end a nd continues in a northwesterJy direction.. eventuall y o utfalling to th e South Platt e R ive r There is limited exis t ing developm ent w ithin t11e West Fork Second C reek Coll e ction S y stem B as in The land i s mainl y agric uJturaJ with dry l and fruming and pasture in th e uppe r reaches. The Hig h Line Canal temunates at the West F ork. The s ustain e d unused flow in tbe Hig h Line Canal has historic aJl y been wasted t o the West Fork downstream of 641h Aven u e and the flows have erode d the channel o n t11e West Fork At Towe r Road th e W es t Fork channel is about 15 fe e t dee p vYi t h ve rtical and very stee p un stable bank s. The conflue nce of Second Creek and the West Fork of Second Creek i s a wide relativel y flat area suppo rtin g a s t and of cottonwood trees. Som e wetland areas are p resen t in th e uppet r e aches of th e West Fork. but. as the channel has e rod e d th e channe l banks have becom e incised and support onl y a narrow b a nd of wetland o r riparian vegetation The floodplain i s contained within the channe l except a t road crossings, w h e r e overtoppin g may occur The ban k s are un s tabJ e a nd some lateral channel migration may occur dming large flows. Identified Drainage Problems/ Deficiencies: West F o r k Second Creek is largel y und evelo ped, and drainage i s primaril y via open channe l s and swal es. Th e re a r e few stom1 drain pipe systems w ith i n the basin Since th e r e i s littl e developm e nt t h e system c urrentl y functions p o ndin g or drainage probl e m s except f o r channe l e rosi o n w h ich w ill b e exacerbat e d b y further devel opme nt. Proposed Capital Improvements: Th e drainage basin i s ctme ntl y mostl y undevelope d w ith a low imperviou s n ess. TI1e Second Creek and Dir ec t Flow Area 005 3 Outfall Systems Planning Study Preliminary D es ign complete d b y Kiow a Engineering for the Urban Drainage & Flood Contro l Distric t in May 1 990, assumes the upp e r reach es of'thc basin will be developed w ith an average 70 % imperviou si1ess. The OSP call s for channel s tabilization measures b y con stmc tin g a se1ies of drop st mctures a lon g the c h aw1el. These impro ve m ents will b e construct e d commen surate with devel opme nt. The Pefia Boulevard Transportation Corridor i ncludes land extendi11 g 250 feet from cente rlin e for a futur e light tail / commute r r ail lin e. Therefor e exis tin g and propose d dete nti o n basi n s are not imm ediately adjacent to P efia Boulevard Two r eg1onaJ d e t e ntion facilities rue currently pro posed in th e basi n a l o n g wit11 multiple smaller d ete ntion faciliti es servin g futttre d evefop m ents. P ro ject A : Hi ghpoint Ope n Channe l The 101.9 acre-foot "Highpoint Pond i s l ocate d east ofT ower Road a nd north of72d Avenue and was master plann e d t o r e duc e flows to historic conditi o n s in the West Fork Second Creek. Open chann e l impro ve m e nt s w ill b e r equire d to serve as conveyance from futur e deYelopment areas into th e W es t Fork of Second Creek. These impro ve m ents w ill b e requ i r e d a s deve l opment occllrs to ade quatcJ y con vey flows to th e cnlvert upstrea m of72nd Avenue on the West Fork of Second Creek. September 201-1 Project C Second Creek Grade Control Chann el stabilization is r equired o n about 18:000 lin eal feet of the W est Fork Second Creek. l11e c hann e l will b e grad e d fro m stee p unstable banks t o a channel with s Jop e d ove rbank s and with a top width of about 40 to 45 feet. An estimated 35 drop stmctures a r e a lso proposed to stabi lize the channel b y s hallo wing the exist i n g g rad e. P age 68

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li E I ;; :1! ., i E 0 0 ol z 'I) .8 :r :; I Q. ::; 0 OJ) I Q 8 D :r l Q. I e e' ;:;: Key Map . . 0 .. .. .. .. ... 750 1,500 Feet 1 inch equals 1 500 feet Commerce City Adams County For Detailed Hydro l ogy See T ec hni cal Appendix and Work Map Adams County 1 3700 0 1 1 ...... Collection System ...... Boundary Proposed Storm Pipe .... UDFCD Study Recommendations X Proposed Pipe Disconnect L ege nd Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location [ 3700-03) r' Proposed Detention Basin Existing Basin 11 Potential Inundation L.__J Area Planned Transit Line F Adams County '-?+' \ I \ Adams County ............... .Aurora --,. \ ......... . ...... ... .. . .. .... .. [ 3702-01 ) "c Pr o posed Proje c t s A HIGHPOINT OPEN CHANNEL: $7,449,981 Pond826 Existing Transit Line D City and County Boundary ... : Other Municipalities D Other Counties Pend ..... C SECOND CREEK GRADE CONTROL: $10,388,884 Basin 3501-01 West Fork Second Creek Denver Storm Drainage Master Plan Page 69

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D e n ve r Stonn Drain age Master Pla n Basin 3700 -01 (First Creek & Pefia Corridor) Existing Basin Des cription: The First Creek Collection System Dr ainage Basin is located south ofDIA and crosses P efia Boulevard just n orth of 56th Avenue West of Pefia Boulevard. First Creek flows through the sout h eastern portion of the Rocky Mountain Arsenal. First Creek ente r s Rocky Moun t ain Arsenal wi th an incised low flow channel and wide floodplai n Basin 3700-0 I is ent ir e l y within t h e City and COLmt y of Denver and has b ee n defined as the area within the wi de P efia Boulevard corridor owned b y D I A. that will not experience further devel opment. The east corridor ofthe light raiVcOJrunuter train was under construction cast of Pefia Boulevard at the time tb.is report was published. A portion of the First Cr eek B asin extends up stream t o the outle t ofthe regional Green Va11ey Ranch Golf Course d e tention pond. Thi s basin i s 2.23 sq uar e miles a nd will includ e future dcvelopmer1t. G e neral imperviousness is 8% a lon g P e fia Boule var d and abou t 65% further upstream on First Creek. Identified Da-aioage Problems / Deficiencies: The Pefia B ou l evard corridor is a wide a rea for P ena B oulevard and th e new l ight r ail/co mmu ter train and contains sit es planned for regio11al dct entiot1 before o utfallin g into th e Rocky Mountain Arsenal The basin is active l y being developed in accordance w ith c urr ent drainage crit eria. whic h is the l 00-year s t o rm event Therefore no exi s tin g deftcie n c ies h ave been id e ntifi ed. Proposed Capital Improvements: Urban D rai n age & Flood Control Di strict prepared drainage master plans prior to development of the basin
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Key Map 0 700 1,400 Fo r Deta il ed Hydrology See T echnical Append i x and Work Map Highpoint Detention Pond 101.9AF Collection System ...... Boundary / ,... ................. ; l I ;' : . ,. Pond801 PondG Pond 826 ( 3700-03 1 Pond800 l 3501-01 1 I NTOWER RD I .t & ". # Q : l \ Adams County Proposed Storm Pipe --UDFCD Study Recommendations Legend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location t I I w > w ,. ,: .. ;' Proposed Detention Basin Existing Basin 11 Potential Inundation L.....l Area Planned Transit Line Existing Transit Line D City and County Boundary Pond ( 3700-02 1 ,_./ i. / GVR GC Pond aka Hiq;iay'D Pond 7 aka P ond 808 ..... 369AF .... PondC Pond I / / / / ; I / / / / ( 3900-03 1 .-----/ / I I t ..... _,. ., I Basin 3700-01 First Creek & Pena Corridor

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D e n ve r Sto nn Drai n age Maste r P l a n B asin 3700 02 (First Creek-Green Valley Ranch) Existing Ba si n De s cription: Collection System Ba s in 3700-02 i s primari l y w ithin the C i ty and County of Den ve r but incl u d es some area w ithin Adams COtmty Th e basin includ es a rea w ithin D e n ve r that i s tributar y t o the r eg ional Gre en Val l ey Ranch Golf Course detention Pond also known as th e Him alaya Pond" .and ''Pond 808. '''This basin i s b eing d eve l o p ed b y Gree n Valle y Ran c h and inclu des 2.1 2 sq uar e miles. Fir st C r ee k mns through this bas i n and bis ec ts Gr ee n Valley R a nch w hi c h consists of m e dium d e n sity sin g l efamil y r es id e n ces. G e n e r al imp ervio u s n ess was mas t e r plmm e d as 70 % for th e 2005 Storm Draina ge Mas t e r Plan and in th e 2009 Storm D r ainage Mast e r Plan it was l owered b ase d on actual im pervi o u s n ess. The new v alu es h ave been carried forward t o this Master Plan up date. See First C reek (Upstr eam of Buc kley R oad) Major Draina geway Plan : Conceptua l D esign R eport pr e pared b y Moser & Associates for the U DF CD and publ is h e d in August 20 I 0 for flows u p stream of E 38th A ve nu e and N Picad ill y R oad ( DP 076). Ide ntifi e d Drainage Problems/De fici e nci es: Th e b asi n i s mostl y developed and was deve loped in accordance w ith current drain age criteria, w hich is th e l 00 -ycar sto rm event. The r efo r e no exi sting d eficiencies have been iden tifi e d Proposed Capital lmpovement s: Urba n Dr ainage & Flood Co nt ro l D is t rict pr e p a r e d drain age ma ste r p l ans pri o r t o de ve lopm e nt of th e ba si n and has re quir e d incorp o r ation of re gio n a l wate r quaJjt y and d ete ntion into l and A U d eve l o pm e n t in the Firs t C r eek Dr ainage Ba s in m ust detain a n d treat wate r qualit y o n-sit e or in regi o n a l detention basi n s since runoff w ill flO\v into the R ock y M o u ntai n A r se nal. Th e Arsena l h as str ict agree m ents for t h e quantit y an d q u a lit y o f stonnwatcr nmoff into the federal prop erty. Th e First Creek (Upstream of Buckley R oad) Major /)rabwge wa y Plan: Conceptual De s ign R epo rt recommended floodplain preservation w i t h in B as i n 3700-02. The r e are no additional plan n e d impr ovement s for the b asin, b eyo nd th e capit a l co n st ruction r e quir e d for th e Gre e n Valley Ran ch deve lo pment. Master Plan Agreements: Mm1y doctiments and agreeme nt s have b een compiled for the First Creek Drain age B asin. T hese d oc um en t s specify I 00year discharges and storage v olumes. TI1erefore nothin g in th i s Master Plan s hall take precedence over t hose agreemen t s or specified disc h arges. TI1is st ud y was completed for the p tt rposes of ana lyzing initial storm flo ws for t h e 2 and 5 year eve nt s. Agreement 99-03.11, d ate d Janu ary 22. 200 1 states the following for the G ree n Valle y Ran c h Golf Course P ond'' or the ''Him alaya Pond '' (#8 08) : Master Plan De s ign Paramete r s ID Peak Infl ow Peak Outflow Volume Jur i s d i ction No. (cfs) (cfs) (AF) 4857 4 306 263 D e n ve r Howeve r the p ond was constructed with 369 acre-f ee t of storage rat her than the 263 acre-feet per th e agree m e n t. September 201-/. Page72

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0 0 z ll :; a.' z Vl 0 N "' J Key Map ....... ..... ..... '--Cl 0:: 0::: uu 5 2 ( 3900-03 1 PondD2 ( 3700 -0 3 1 [ 3702-0 1 1 1 3700-01 1 tu (/) tuu (/) Cl uu 2 2
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D e n ve r Stonn Drain age Master Plan Basin 3700-03 (First Creek-Dogwood & Blue Gram a Tribs.) Existing Basi n Description: Collection System Bas in 370003 is locat e d w ithin the City and County of D e n ver and Adams Co unty. Th is basin h as be e n d e fin ed as the area drainin g to the D ogwood Gulch Tributar y and the Blu e Gtama D raw Tributar v This b asin is 2.61 square miles and i s active l y b eing developed The sub di visio n s of'Denver f ntemati"anal Busi n ess Ce n ter,'' H i g h P o int," and Single Tree at DIA'' are 'v\ithin this drain age basin G e n e ral impervious n ess at full d eve l opment, \Viii b e arow1d 65% Identified Dtainage Problems/De f iciencies: The basin i s active l y being d eve lop e d in accordance with current drainage criteria which i s th e 1 00-year stonn eve nt. TI1e r e f ore, no exi sting d e fici e nci es have been id e ntifi e d Proposed Capital Improvements: Urban Drain age & Flood Contro l Di stric t prepared drainage m aste r p lans prior t o d evelopment o f th e basin a nd has requ.ired incorporation of regional water qualit y and d ete n t ion into land plannin g. A ll d evelo pm e n t in t h e First Creek Dr a inag e Ba sin m us t detain and treat wate r quali ty o nsite or in regional detention basins s inc e nmoff w ill flo w into the Rocky M o untain Arse nal. The Arsenal has stric t agreements for th e quantity and quality of stonnwater nmoff into the federal property. The First Creek (Upstream of Buckley Road) Major Drainagt.."wtty Plan: Con c eptua/J)esign R eport, prepared by M oser & A ssocia tes fo r the UDFC D and publi s h e d in August 2010 contain e d no recomm e ndation s in thi s basin. Multipl e d e t e ntion basins are plann e d t hroughout th e basin in co njun ctio n w ith development both on Gul c h and Blue Grama Dra\V. P roject A: D ogwood G ulch P ond 8 1 2 Tlus 13 acre-foot d e t en tion basin wiU b e constructed as d eve lopm en t occm s It wiU b e locat e d i.n:unedi a t e J y to the east o f th e P e fia B oulevard corridor between 66lh and 681 b Avenues. l11is de t e ntion basin w ill serve t o regu l ate incre ased fl ows from the d eve l opment back into Dogw ood Gul c h as it ente r s th e P e fia corridor Project E : Blu e Grama Dr aw Pond 802 This 33 acre-foot d e t e ntion basin w ill b e constructed as d eve lopm ent occurs. It wi ll b e l ocated immed i a t e l y to t h e east of Towe r Road, b etwee n 60th and 64th Avenues Thi s detention basin w lll se r ve to regulate incr ease d flo ws from t h e d eve l opment back into B l u e Grama Dra w before c r ossing Towe r Road. Project G : Blu e Gram a Dra w P ond 8 1 6 Thi s 40 ac re-foot de t en tion basin .. in Au rora. will b e cons tntct e d as d eve lopment occurs It will be loc ated immediatel y to tbc nort h of 60th Aven u e and to tbe wes t of the Hi g h Line Canal in Adams Count y This d e t ention basin w ill se r ve to regu l ate in creased flo ws from the development back int o Bl ue G nun a Dra w H: Blue Grama Dra w 826 th TillS 23 acre-foot detention basmts pa rti ally co nstruct e d It wtll b e l ocated unm ed tat e l y t o t h e south of 60 Avenue and w ill eventuall y b e on b o th s ides of Argo tme Street. Thi s dete ntion bas in w i ll serve to regulate increase d flo ws from the d evelop m e n t back into Blue Grama Dra w. Currently only a p o rti o n of thi s d e t e ntion basin at th e east sid e o f Argo nn e Street i s co nstru c t e d as only a potti o n of th e tributar y area is developed The other portion of thi s d ete nti on basin at the wes t side of Argotme Street b e constructed to offe r an additional 11 acre-foot sen, ice l eve l s for the future deve l opm e nt. September 2 014 Opeh Channel Impro ve m ents Gene rall y t h is basin requires a series of o pen channel impro ve m e n ts associated with each d e t e ntion basin to se r ve as co n vevance channels for bo t h D ogwoo d G ulc h and Bl ue Grama Dra w. These o p e n channel improvements : and associated culvert crossings. will be required as d eve l op m ent occur s. Master P lan Agreements: Many do c u ments and agree m e nts tha t specify 1 00-year di sc harges and s tor age volum es Jm v e been compi l ed for the first Creek Draina ge B asin Th e refor e : n othi.ng in thi s M as t e r Plan shall t.a. k e precedence ove r those agreements o r specified dis ch arg es. This study was completed for t h e purposes of analyzing s t oon flo ws for the 2-and 5-year eve n ts Agreement 99 -0 3 II, d ate d Janu ary 2 200 I sta tes th e follo w mg : Master Plan D esi2n Parameters m Peak I nflow Peak Outflow Volume Jurisdiction No. (cfs) (cfs) (AF) 800 419 120 1 1 D e n ve r 80 1 1226 655 3 7 Aurora 802 982 92() 33 D e nver 812 444 216 13 D e nver 8 1 6 864 438 40 A uror a 826 589 ll:W 23 D e nver P age 74

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K ey M ap 0 750 1 ,500 For D e t a il e d Hy d rology See T ec hn i cal A pp e nd i x and Wor k M a p 0 e::: e::: UJ 3:: 0 1-2 1 37000 1 1 ffi 3:: 0 1-2 ...... Collection System ......, Boundary I(/) I .. Proposed Storm Pipe .... UDFCD Study Recommendations \ Adams County \ \ \ \ High Lino C--... ili)IJf ----------,. ...... 1 350 1 0 1 1 '., \ ..... I I 1: --........... ..,1 [ 370 002 1 I(/) ...J 0 0 a. e::: UJ > ::::; 1 3 702 -0 1 1 I ( \ t I I I I I I I I I I I I I I I I I I I I I I I I I I I I .... ....... ... . ........ . . Adams County ... .... ................ ....... ........................ Pr o posed Pr o j ects E POND 802 DETENTION: $9,138,763 Existing r --' Proposed Detention -+-Existing Transit Line Basin 3 7 0 0-0 3 '-.J Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatl on g City and County Boundary D 0 gw 00 d & B I u e G r a m a T ri b s -E x isting Surface Flow L___J : Oth e r Municipalities Feet Proposed Pipe Area 1inchequa1s1, sooreet X Disconnect SignificantFioodingLocation -+-PlannedTransitline Denver Storm Dr a inage Mast e r Plan P age 75

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D e n ve r Stonn Drain age Master Plan Basin 3702-01 (First Creek-Tributary "T") Existing Basin Description: Collection System Basin 3 702-0 I is defined as t he portion of D e nver draining to the channel known as Tributar y T which e nt ers D e n ve r near N Picadill y Road and E. 48111 Plac e. This basit1 is also ex'te nd s in to Adams County. The basin area i s 0.9 1 square mil es and will include futur e d eve l o pm en t and the Green Vall ey Ranch G olf Course. O ve rall m aste r planned im pe r v i o u s n ess i s about 70 % This tributat y extends farther up stre am b eyon d th e limits of t hi s basin into Adams Count y. The upper reach es of Tribut ary T Ba s i n have been master pla n n e d for d eve l o pm ent under th e direction of Urban Drainage & Flo o d Control Di str i c t b y Wright Water Engineers in 19 90 Turne r Collie & Brad e n in 2000 MuUer Engineering in 2003 and Moser & Associates Engineering in 2010. Jn a ddition, deveJopmeut e ngineer s have also stu di e d th e basin a nd inc lud e M a rtin & Ma1tin in 1 998 Vestal Enginee1ing in 2004 and S tantec in 2005. Oth e r d eve lopm ent e ngi n ee r s h ave also co mpl ete d studies o f the basin See First Creek (Upstream of Buc kley Road) Major Drainageway Plan: Co nceptual D esig n Report prepared b y Moser & Associates fo r the UDFCD and publi s h ed in August 20 10 for flo ws u p strean 1 of Green Valley Ranch Bl v d a nd N. Picad.ill y Road (DP 070) ldentified Drainage Paoblems/Deficienc i es: The b asi n i s act i vely being de ve lop e d in accordance wit h curr e n t dra i nag e cri t eria. which i s the 1 00 year sto nn eve nt. Therefore n o exis tin g 2 and 5 yea r d e fi cje n c ies ha ve been identifie d Proposed Capital Improvement s: Urban Drain age & Flood Control District prepared drainage maste r plans prior t o d evelo pm e n t of th e basin and has r eq uired in co rp o ra t i o n of r egio n a l quality and detention it1to land planning. All development in the F irs t Creek Drain age Ba s in m us t detain and treat wat e r quality on-site or in regional dete nti on basins since runoff wi U flo w into the Rocky Mountain Arse nal The Arsenal has stric t agreements for the quantity and quality of s t ormwat e r mnoff into th e f e d e ral property. Th e First Creek (Upstream of Buc kley RoacO Major Dralnageway Plan : Conceptual Design Report recommended floodplain preservation w i t hin Basin 3702-0 1. There are no further planned improvements for the ba sin, b eyond t h e capit._
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Key Map Pond 826 .A-""' __ ,.,. ..... ..... ....... i \ ____ ... '\ [ 3700 -01 ) "'-,. [ 3900 03 ) \ Green Valley R anch West Pond 8 0 1 PondG [ 3700 03 ) PondC 1 / \ ....... ) -Adams County ....... ... ... .I \ ... GVF<' C( P qnd a k a Himal aya R ond. aka Pon ct; B O B 3 69Af Pond02 i ---' ""\ :--' \ .. \ .. ( I [ 3700-02 ) \ \ \ 1-tin"'!.. ....... .- "'" ti],o .... -., / ........ (;"Ca. \ ..... -.. ..... nil/-. I ........ ,..,, ............. .. ,, Aurora ..... ...... Tribut:>r y T Q"'" = 2,492 (Moser '10) Q,oo = (Moser '08) Q,oo = 371_8 (Mu ll e r '04) Q,oo = 2322 (Boyl e '03 ) Q,oo = 2655' (TC B O SP ) Q,oo = 2510f (Sellard s & G rig g '01) ....... :--.... . .. / . I / \ ,""' ..... NOTE: See First Creek (Upstream of Buckley Road) Major Drainageway Plan: Conceptual Design Report, prepared by Moser & Associates for the UDFCD and published in August 2010 for flows upstream of Green Valley Ranch Blvd. and N. Picadilly Road (DP 070). ... .... .... ... ........... ... ..... Adams County ............................... : .................. ................ Adams County

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D e n ve r Stonn Drain age Mast e r Plan Basin 3900-01 (Irondale Gulch-Stapleton) Existing Basin Description: Thi s collection system basin is locat e d w ithin Section 10 of the form e r airport, Stapleton R e d eve lopm ent s it e (Ci ty and Coun ty of D e nver) and partiall y w ithin the R ocky Mout1ta in A rse nal (Adams County) TI1e basin i s a tributary to Irondal e Gulch, whic h is tributary to t h e South Pl atte Ri ve r. The ba sin consists of about 140 ac r es and is c urr e ntl y tmd eve l o p e d except for fonner mn ways and storage of c rush e d co n c r ete. The bas in was si milarl y d e fin e d in the 1 989 D enve r Drainag e Maste r Plan but includ ed m o r e land w ithin the Arsenal n o rth ofirondale Gulch in Adams County. T opography wi thin th e basin is characterized by ge n e rall y flat terrain. Di sc harg e f r o m this basi n flows t o t h e north ( d ow n stream) into the Rock y Motmtain Arsenal. irondal e Gu lc h does not have an improved chann e l to the South Platt e River, and therefore runoff in the basin is controlled b y d e t entio n and retention basin s The r e are also limitati o n s t o di sc harg es into tl1e Arsen al. The redev e l o pm ent of St aple ton w ill Includ e detention to co ntrol nmoff. Identified Drainage Problems / Deficiencies: In genera l the r e are current l y no trunk storm pipes within this basin. D e p ress ions b e tween the run ways have captu r e d s t onnwate r run off and direct e d it via overland flo w into Ir ondale G u lch D ischa rges from thi s basin into the R ocky Mo u ntain A rse n a l mus t be limit e d to historic conditions. The previo us s tud y for thi s basin was th e 1995 Stapleton Area Ouifall Systems Plan (OSP) b y Urb a n Drainage & Floo d Control Di stric t and McLaughlin Wate r Engineers which set the di scharge for ex istin g and d evelope d co n ditio n s as shown. Potential Improvements: Th e Stapl eto n D eve lopment Master Plan includ es a detention basin w hi ch will be constructed i n t hi s basin at t b e D e n ve r bord e r comme nsurat e with d evelopment, t o limit discharges to hist oric co ndition s Propos e d detention b asin ( Pond #2 I ) i s at the b o rd e r of t h e R oc k y Mow1tain A r se n al. Th is d e t e nti o n ba s in i s est im ated to b e about I 0 a c r e-feet and v ill rel eas e into the A r se nal at the d e fin e d historic rates. September 201-/. P age 78

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1i : -5 v I 1i J z '#,' l o..' z V> v !:i ., l 1 K ey Map 0 48AF 178AF Commerce City .. .. . .. . . Pond 102 68 .6AF ( 0058 0 1 ) Adams County ............. I ., i ............. .. I [ 4 000-01 ) ___ ) [ 4 400-01 ) Ladora Lake Southgate Pond NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. Derby Lake / t I t I t t I t I 1 \ \. \ $ N L ege nd B 3900 01 .... Collection System Proposed Storm Pipe Existing Storm Pipe ;--I Proposed Detention -+Existing Transit Line as In For Detailed Hydrology ...... Boundary Basin } 0 600 1 200 See Technical Appendi x ._ UDFCD Study Designed Storm Improvement Existing Basin D City and County Boundary StapletOn -ar1d Work Map Recommendations '}_ Existing Surface Flow 11 Potential Inundation Ot M "' L__J ,: her unicipalities : Feet Proposed Pipe Area 1 inch equals 1 2ooreet X Disconnect Significant Flooding Location -+-Planned Transit Line counties Denver Storm Drainage Master Plan P age 79

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D e n ve r Stonn Drainag e Master Plan Basin 3900-02 (Irondale Gulch-East Montbello) Existing Basin Description: This collection system basin is locat e d fully wi thin the Montb e llo nei gh borhood in the City and County of Denver. The b ou ndar ies of thi s basin are 561h Avenue to the n ort h C han1bers Road to the eas t tl1e no rth e rn boundary of Basin 390 l-0 l t o the south and P eoria Street to the west. Th e basin consists of about 1 ,22 1 acres and is fttlly d eve lop e d w ith r esidentia l n e i gh borh oods Low flo ws are conveyed in open channels and pipe systems, w hil e high e r flo ws are conveyed overland tJn o ugb tb e s tre ets. Topograph y is characterized b y ge n eral l y flat t errai n and there are no large, regional detention facilities internall y w ithin the ba sin. D ischarge from the basin flows genera ll y n o rtherl y through a series of co ncr ete channels and pipes lmtil crossing under 56th Avenue. A regional d etent ion facility known as the "'Havana Pond or So uth gate P ond" i s lo cated on the Rocky Mountain Arsenal property n o rth of 561h Avenue Beyon d that point flo ws a lso e nter L a d ora L ake and Lak e Mary o n the Arsena l prop erty V ery littl e flow is di sc harg e d t o Ir o n d al e Gul c h from Lake Mary excep t in large even t s. Thi s basin c urr e ntl y has 7 s torm pipes that cross north under 561 h Avenue. East of P eoria Street i s a s tom1 pipe running along R evere Street di sc hargin g flows und e r 561h Avenue a t d esign point 40 The r e are other minor stom1 pipe s under 561h Avenue to each side of d esig n point 40 but all flows from the contributing area within B as in 3900-02 we r e m ode l ed t o en t e r th e RMA at design point 40. Fw:th e r eas t of d es ign point 40 is desi g n point 5 1 Flow i s collected in a stom1 pipe syste m and di scharge d to ail o p en c hannel along U va lda Street. Thos e flows a r e conveved under 56th Avenue to the RMA Other pip e systems discharge at design p o ints 48 and 49 int o a ditc h tJ1e north side of 561 h Avenue. Basin 3900-04 tlo ws int o Basjn 3900-02. Upstream runoff, attenua ted in the Chambers l Pond flo ws into B asin 3900 -0 2 at Chambers Rd and 48'h Avenue Identified Draina ge Problems/Deficiencies: This drainage b as in is essenti all y fi1lly developed with single-family residential properties. B y D e n ve r c rit eria, the initial stom1 is a 2 year even t for resid ential areas The Irondale Gulch Stornnvater Outfall Systems Plan ami PrelimintiiJ Design R eport d ated May 1 990 b y Wri ght Water Engineers states 'TI1e Montbello area cun-ently suffe r s from a lack o f adequa t e cap aci t y for major fl oods. The exis ting c hannel s have the capacity of around the 5 -to l 0-year fl ood." The concrete trapezoidal channels and stmm pipe syste m s that are c urrentl y in pl ace apparently h ad a d es i g n goal to convey the 10-year flo w. H owever du e to c hanges that occtmed during construction, some systems a r e ove rsi zed: w hil e others are undersized Specifica.lb the concrete trap ezo idal channel in 53rd Avenue was lik ely plan n e d to e:-..1 eu d further east past Chambers. H owever as-built conditions d irec t all stom1-water cast of Chambers e a sterly into Parkfi e ld L ake Potential Improvements: The 1 990 study was comp1e t ed to upgrade alf fa c ilities wi thm the M o ntb e llo Area to 1 00-year capac1ty. TI1e greatest const rain t was the und e r size d road cross ings o ver the open channels. B y reconstmctin g these crossi ngs major conveyance fa c iliti es wo uld be a bl e to conve y larger storm events. ln a reas where additional capacity is required. the 1 990 study proposed replacing the sloping wall s w ith vertica l concrete wal l s to esta bli s h a rectangular concrete channel wi thin the right-ofway ofthe exis tin g channel. A site vis it con finned that four Irond a l e Gulch cu l ve t s a long U valda Street have been upgr a ded in howeve r tJ1e remaining 7 c ul ve rts along Ir o ndal e Gulch have not been co nstmcte d A recommendation was also mad e in the 1 990 stud y to change the bottoms of the existi n g concre t e channels to wet land s for wat e r qualit y ben e fits Ho weve r the se changes ha ve not been impl e mented 1l1e r e has bee n greater e m ehas i s o n d ete n t i o n to r e duce September 20/.J. flo ws t o the capacity o f existing systems As upstream d eve lopm e nt has occuned, detention has been required to keep th e flo o d p eaks from in creasing above ex isting l eve l s The Irondale Gulc h Outfall Systems Plan Conceptual Design Report was co mpl eted in 2011. H ydro lo g y was updat e d for tJJe en tir e Irondal e Gulch wate r s h e d in c ludin g Bas in 3900 02. l11e upper lim it o f proposed improvem ents in the OSP was the D enver/ Adams Cotmty bmmd ary and th erefore, no impro ve m e n ts were eval uat e d or s h ow n in D e n ver. Proj ec t A: E 53rd Ave Impro ve m e n ts a nd Project 8 : E M axwe ll Pl. Impro ve m e n ts The 1990 Urba n Draina ge & F l ood C ontr o l Distri c t study focused o n major drain age\-vay conveyance Impro ve m e nts n eede d beyond those ev alua te d in the previou s study a r e additiona l stom1 drain l a t e ral s. TI 1ese lateral s are s u ggeste d to r e duc e flo ws in street s dUiin g minorevents and reduce p onding and cross st reet flow. Master Plan Agreements: Man y documents and agree m ents that s p ecify 1 00-year discharges and s t o rage vo lum es have bee n co mpil e d for the Irondal e Gulch Drain age Basin. Therefor e nothin g in thi s Master Plan s hall tak e precedence over those agree m ents or speci fied di sc harg es. Thi s study was complete d for the purposes of analyzing in it i al s t orm flows for the 2-and 5-yea r events. R efur to Urban D rainage & Flood Control Distri ct mas ter plans for 1 00-yca r di scha rges. P age 80

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0 Key Map 0 Adams County 1(/)
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D e n ve r Stonn Drain age Master Plan Basin 3900-03 (Irondale Gulch Parkfield) Existing Bas in Description: This collec tion system basin contains the To wer Outfall Lateral and the Highlin e Lat eral and i s loc ate d through thre e neighborh oods in th e City and Cout1ty of D e nver : P a rkfield D e n ver Cotlllection and Green Vall ey Ranch The boundari es of thi s ba sin arc 56th Avenue and the so uth e rn bounda ry ofthe First Creek Basin to the n o rth th e m iddle ofthe G reen Valley Rancl1 n eigh borhood to th e eas t the north e m b o undar y of Bas i n 3900 -04 and 38tb Avenue to th e soutl1; and Chambers Roa d to th e west. Th e b asi n cons i sts of about 1 873 acres and i s partiall y developed wit h reside n t ial n e i g hb o rhood s, wi th plan s for commercial and r esi d en tial d evelo pm en ts in t h e near futur e Low flo ws a r e co n veye d th ro ugh s tom1 p ipes and open channe l s to r eg iona l d eten t io n facilities includin g Parkfi e ld Lake Parkfi c Jd II Lake Hi ghline Poud Silverado I Pond a nd two Green V a Uey Ranch d e t en tion facilities. Hi g h flo ws are co n veye d through some of the stonn pipe syste m a nd overland thr o u g h the stree t s t o tl1e d e t e ntion a r eas. T opog raph y is characterized b y gen e rall y fl a t tc n ai n with nmoff disc har ge flo wi n g ge n e rall y to the northwest toward Parkfield n Lake in the north west corn e r of 56th and Chambers. ldentified Drainage Paob l ems/Deficiencies: Th e Hi g hlin e and Silve rad o I Pond s requir e d m o difi ca tion due to im p acts of the new RTO FasTracks East Conidor light rai l/commuter tr ai n Th e Hi g hlin c Pond slig htl y excee d s, b y 0.1 acre the aJiowablc snrface acreage according to an internal memo b etwee n D e n ve r Aurora a nd D enver Int e rn a t ional Airport ( DIA ) w hi ch sets the max_imum p o nd acreage to 7.6 acres. Th e c han nel down s tr eam o ftl1 e Hig h lin e Pond t o tl1e wes t of P e iia B oulevard w lll need to b e mo nito r ed to detenn in e how the channel i s b e ing impacte d b y e ro sio n fr o m pond dis c harg es Potential Improvements: All impro vements proposed in the 2005 Master Plan h ave b ee n builL No additional potential c apitaJ impro ve m e nt s we r e propo sed for this ba sin w ithin the City and Cou nty of D e n ve r reach The d etent i o n b as in s proposed in tJ1e Irondale Gulc h Stormwater Systems Plan and Preliminary Design Report dated May 1990 b y Wright Wat e r Engin ee r s h ave b een constmcted. Th e Ir ondale Gulch mai.11ste m do es not :flow thro ugh Basin 3900 -0 3 so n o recommended crossing improveme nt s apply t o Basi n 3900-03. The from/ale Gulc h Outfall Systems Plan Conceptual Design R e port was completed in 201 1 H y drolo gy was updat e d for tl1e entire Ir o ndaJ e GuJch watershe d including Basin 3900-03 Th e up per l imit o f pro pos e d improvements in the OSP was th e D etwe r/Adam s County bot Uldar y and th erefo re, n o impr ove m e nt s were eva lu ated or show n in Denver. September 201-/. P age 82

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K ey Map .... ..... .... ........ .......... -.. __ Adams County 4'-o/J. O'o;., ............ c,//zy;, ..... "" GREEN VALLEY RANCH ........ ..... .... l [ 3901 -01 l Gateway Park Four aka Chambers II Pond 0 750 1 ,500 For D e t a il e d H y drology See T ec h n i cal A pp en d i x and Wor k M ap ..... Collection System ...... Boundary Adams County Proposed Storm Pipe ..... UDFCD Study Recommendations 1 390 102 ] L egend Existing Storm Pipe Designed Storm Improvement --E x isting Surface Flow Significant Flooding Location [ 3 7 0 0 0 1 l r' -- Proposed Detention Basin Existing Basin 11 Potential Inundation L__J Area Planned Transit Line [ 37 0 0 -0 3 ] PondC Existing Transit Line D City and County Boundary Adams County PondD2 ,. .......... __ NOTE: Trans-basin flows shown with a heavy black arrow are based on e x isting storm drain s y stems, not proposed drainage improv e ments. [ 3702 0 1 l Basin 3900-03 Parkfield

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D e n ve r Stonn Drain age Master Plan Basin 3900-04 (Irondale Gulch-Majestic Commercenter) Exist ing Basin Description: Thi s collection sys t e m basin contains the Bollin g Dri ve Trib utary and i s located in th e City and County of D e n ve r and th e City o f Aurora The botmdari es o f thi s b asin are the southern b o ttndar y o f Basin 3900-03 t o th e north Pica dill y Road to the eas t the northern b ounda r y o f B asi n 39 01-02 and Union P ac ifi c Realty Compan y to th e sout h and Chambers Roa d to t h e west. Th e bas in cons i s t s of about l 1 8 L acres and i s mo st l y w1deve lop e d w ith plans for r eside ntial commercial and ind us tri a l d eve lopm e nt s in the near f utu r e. Th e future s ubdi vis ion s along the Bollin g Dtive Tributary includ e D e n ve r Connection G a te\ovay Park and Com.merc e n ter. Thi s tributar y also p asses through the P efia Boul ev ard right-ofw ay. Low flo ws are currently conve ye d t hrou g h open c hann e ls to regional d e t e nti o n fucilities including th e Silverado II Pond and the t wo Majestic Comme r cen t e r Ponds Hig h flo ws a r e conveyed t hrou g h the same open c hann e l s to the detention Topograph y is characterized b y generally flat t e rr ain w ith fl ows disc har g ing generall. y to th e n o rth west toward th e propo se d Chambers I Pond. R u noff from the Citv of Aurora flo ws into the C itv and Coun tv of D e nver near d esign p o int 352. A G ateway Park reside11tial w il l be constructed oftllis design p oint wi thin the Cit y of A uror a Runofffrom th e M a j estic Commercent e r v iii flow through the Gat eway P ark d eve l opmenL An open c hann e l the B o Jlin g Dri ve chan n e l was recently cot1stru c t e d do w n stream of To we r Ro ad to co n vey flows from Aurora s Co mm e rc e n te rto the Sil verado U d e t entio n Pond s and into D e nver TI1e cha nn e l was designed for th e 1 00 year eve nt and was realign e d t o allow for d eve l op m e nt. A futur e culvert w ill b e co n structe d und e r T owe r R oad b y the C it y of Atuora Identified Drainage Probl em s /Deficiencies: TI1e Commercente r development h y drolo g i c model has b ee n adopted for thi s s tud y w ithout r evis ion ln 2003. B oy l e En g in ee rin g crea t e d a n upd ated mod e l to r UDFCD based o n informa tion provided b y the Cit y of Aurora. That mod e l iufom1ation was adopted unch ange d at the directio n o f Aurora, althou g h the b ase topo g r aphic mappin g was poor Th e infonnat io n was transcrib ed into D e n ve r s GIS w ithout e djts rt was note d that d urin g the c urrent model updat e ce rtain ba s in areas and m o d e l routin g from the orig inal infortnation provided b y t h e City of Aurora could b e remodele d t o m ore accura t e l y match the prop ose d condit ions It is r ecomme nd e d that th e Majestic Commercenter area be r ev i ewe d again to m ore accurat e l y r e present th e fl ows ente rin g the Cit y and Cow1t y of D e n veL Potential Improvements: Stor m drain im provements w ill be constructed commensurate with de ve lopm ent to meet current dr a in age criteria o f I 00year syste m s. P ro j ec t B : E B o lling Dr Improvements An open channel will b e n ee d e d d uring d evel o pm e nt ofthe are a t o dir ect flo ws fr o m ti1e Si l ve ra do n Ponds to the propo se d Chambers I detention Pond This channel sho uld be d esig n e d for th e 1 00 year eve nt. TI1e Silverado U d e t e ntion Pond proposed in t h e Irondale Gulc h Stormwate r Ouifitll Systems Plan ami Preliminary Design Report, dated May 1990 b y Wright Water Engineers bas b ee n con structed but t h e C hamb e r s l Pond h as not. Th e Irondale Gul ch main s t e m does not flo w throug h Bas in 3900-04 so n o recommend e d ctoss in g impro ve ments appl y t o B as in 3900 04 Th e Irondale Gulc h Systems Plan Co11ceptual Desig11 Report was compl ete d in 2 011. H y drol ogy was up dat ed for th e e n t ir e Ir o ndal e Gul ch September 20 /-I wat ershe d. in cl uding B asin 3900 -04 The upp e r limi t of prop ose d i tnprov etue nt s i n th e OSP was t h e D e n ve r /A dam s Count y bounda ry and therefore, n o improvem e nt s we r e eval u ate d or show n in D e n ver. Master Plan Agreements: Man y documents and agreem e nt s that s pecifY 1 00 year di sc b arges and storage vo hune s have b een co mpil ed for the Irondal e Gulch D ra ina ge Basin. Therefo r e nothin g in this Master Plan shal l take precedence ove r t h ose agreements or spec ifie d di sc harg es. Thi s stu d y was complete d f o r th e purp oses of analyzing init ial s torm flows for th e 2and 5 year eve nt s. Agr ee ment 93-04 05 dated April 1 6 1 995 s p ecifies cost s haring agr ee ments l and u se and the I 00y ear discharges and storage volumes for Irondale G u l ch. In Basin 3 900-04 th e Commc r ccnte r Pond s (Auro r a Busin ess Ce nt e r P onds). and Si lver ad o 0 P onds are regulat ed b y t hj s agr ee m en t as follo ws : Maste1 Plan Design Pmameters ID Peak Peak Detention Jurisdiction No. Inflow Outfl ow Volume (cfs) (cfs) (AF) Aurora Busi n ess C e nt e r N /A 393 17 Aurora Silverado Jl 863 2 44 65 D e n ver After t h e 1 995 agre e m e nt th e Silverado II P ond was co n s truct e d to have 87 .2 acre-fee t of sto ra ge. TI1e Silverado ll P ond r eq uir e d m o difi cat ion du e t o imp acts of th e new RTD FasTr acks East Conidor ligh t rail/commuter train Th e East Conidor Memorandum of Unde r stan din g (MOU) b etwee n UD.FCD and th e Re1:,tional Trru1sportation Di s t 1 ict (RTD) d ate d A u g u s t 3 1 2010 dictates that the r equire d vo lume of th e de t e ntion ba s in t o be 87 2 ac r e-fee t and th e ma'C.imum s mfu cc area of th e pond b e 27.4 ac r es P age 84

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0 z, I 0. ,. 0 "' v' i Key Map Parkfield Lake [ 3700-01 ] 1-OQ \('0' Gate way Park )' Four Lake aka Chambers II Pond [ 3900-03] [ 3901-021 #""' .. / l .,_ ....... ____ ....... ,, ., I Aurora NOTE: Trans-basin flows shown with a h eavy black arrow are based on existing storm drain systems not proposed drainage improvements. Adams County Propose d Projects ....... B-E BOLLING DR IMPROVEMENTS: $18, 094,707 Legend 8 3900 04 'il .... Collection System Proposed Storm Pipe Existing Storm Pipe .---' Proposed Detention -+-Existing Transit Line as I n For Detailed Hydrology ...... Boundary ; _. Basin 1 0 750 1 500 see Technical Appendix -euDFcDstudy Designed storm Improvement Existing Basin C':JcityandcountyBoundary MaJestiC Commerce Center e and Work Map Recommendations :)_ -Existing Surface Flow 11 Potential Inundation Oth M L__J : er un1C1paht1es Feet Proposed Pipe Area 1inchequa1 s1,sooreet X Disconnect Significant Flooding Location -+-PlannedTransitLine Denver Storm Drainage Master Plan P age 85

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D e nver Stonn Drain age Maste r Plan Basin 3901-01 (Irondale Gulch-West Montbello) Exist in g Basi n Description: This collection sys tem basin is locat e d mos tl y w ithin th e City and County of D e n ver. The b o undari es ofthis basin are 561h Avenue and the southern b o undarv of Basin 3900-0 2 to the north. Havana Str ee t t o t h e west 1 -70 to the so uth and Chambers Road to the East. -The basin consists of about 2 096 acres and is mos tl y devel o p e d w ith industrial war e h o uses in th e west e m portion of th e basin and r es id e ntial n e i ghborhoods in the eas t e m porti o n of th e basin __ Low flo ws are conveyed wi thin a pipe and chann e l w hil e hi g h e r flows are con veye d overland throu g h c hann e l s and streets Topography is characterized by gen e rall y flat terrain cwd t h e re a r e no regional dete nti o n facilit ies w ithin the basin Discharge from the basin flows generally t o the east and north This basin discharges to the Rocky MatU1tain A r se nal (RMA) at two point s a l ong 561h Avenue. Beginn ing at th e \
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Key Map [ 4400-01 l = i E ii ..; ::: ., -g !; 9 4400-03 0 800 1,600 ... ____ .. ,.. For Detai l ed Hydrology See Tec h nical Appendix and Work Map Southgate Pond ..-. Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe .... UDFCD Study Recommendations 1(/) ::; 0:: 0 UJ a_ z Legend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location I I I l \ \ Adams County I(!) ., ,_g I ...... + .......... : ..... ...... [ 3900-02] -.... -...... (' Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__J Area Existing Transit Line D City and County Boundary Planned Transit Line .. ..... ..... Parkfield l.1Jke NOTE: Trans -basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements .... I I \ \ .. ..... \ \ \ ,... _____ ., .. ......._ [ 3900-03 ] ., l ....... 1 3901-02 ] Proposed Projects _. A-18" UPGRADES: $1,192,050 B E 45TH AVE IMPROVEMENTS : $20,234,481 C-E 47TH AVE IMPROVEMENTS: $10,862,478 ...., D-E 53RD AVE IMPROVEMENTS: $7,156,629 E E ALBROOK DR IMPROVEMENTS: $3,221 427 F E ANDREWS DR IMPROVEMENTS : $1,112, 782 Basin 3901-01 West Montbello

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D e n ve r Stonn Drai n age Maste r Pla n Basin 3901-02 (Irondale Gulch-Gateway) E xisting Bas in De scription: This collection system bas in contains the Montb e llo Trib utary and is l oca t e d in t h e C ity an d County of D e n ve r and Auro ra The b o undaries of t hi s basin are the southern boundary of B asi n 3900 04 to the north Tower Road to the east C h ambers Road to t h e west and 1 -70 to the south Th e ba sin consists of about 62 1 acres a n d is pa!l ia.lly d eve loped with th e Gateway P ark d eve l op m ent and U ni on Pacifi c Realty This t:Jibuta.T) a l so passes through th e P efia B oulevar d right-of-way \ Low fl ows a r e currently con veyed thr o ugh stonn pipes and op e n c h an nel s to regional detention fa c ilities incl udin g the tluec Chambers 11 Ponds an d t h e three Upland P onds. Hi g h flows are conveyed through o pe n c han nels and throug h the streets to t h e d e t entio n a r eas. Topogr aphy i s c h aracterized b y gen e rall y flat terrain with flows di scharg in g gen e rall y t o the west and north wes t toward the three Chambers ll P onds. Drain age from the City of A urora crosses a b oundary into t h e City a n d Cmmt y of D enve r within thi s drain ag e b asin at design points 437 an d 431 Identified Drainage Problems /Deficiencie s : Thi s is a 11ewl y d eve l o p e d basi n a n d drainag e in frastructu r e has b een designed fo r th e l 00-year even t. The refor e no 2and 5 year drai n age deficiencies have been ide ntifi e d Potentiallmprovements : Th e Iro ndal e Gulch StQrmwater Systems Plan attd Prelimina ry D esig n Report, dated May 1 990 b y Wri g h t Water Engineer s s h owe d d ete nti o n b asins that are regula t e d b y later agreements as d esc rib e d be low. Necessary drain age capital impro ve m e n ts w ill be constntcted b y the developer to m ee t c urr ent drainage cri t eria The Irondale Uu lc:h Outfall Systems Plan C onceptual Design R epor t was compl e t e d in 20 1 1. H y d rology vvas updat e d for th e e ntir e Ir o ndale Gulch wat e r s h ed including Basin 390 1 -02 Th e u pp e r limit of proposed impro ve m ents in th e OSP was the D e n ver/ Adams Coun ty bo un druy and. therefore no imp rovemen t s were evaluat e d o r s hown in D enver. Agreement 93-0 4 05 dated Aprill6, 1995 sp ecifies cost s h aring agreements land u se and the 1 00-yea r dischar ges and s t orage volumes for Irondale Gulch In Basin 390102 the Upland D ete ntion Pond s and Chrunbers U P ond are r eguJate d b y thi s agreem e nt as foll ows : Master Plan Design Parameters ID Peak Peak Detention Jur i sdiction No. Inflow Outflow Volume (cfs) (cfs) (AF) Up l and D etentio n Pond s 948 56 42 Aurora UP Realty C h an1bers U Pond 663 2 1(} 32 D e n ver UP R e altv *The C h ambers H D etent10n P ond has bee n construc ted and t s located b e t ween E 40111 A ve nue and E Boll ing D rive east ofN. Chambers R oad. It is commonl y known as Gateway Par k Four L ake as shown o n the accompan y ing map. September 201-/. P age 88

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Key Map [ 3900-02 ) \ """-o4--......... ..... 0 .............. [ 3901-01 ) ...... ... Q1= 31cls Os= 5 9 cis E ANDREWS DR Q ,00 = 203 Adams County 600 1.200 Fo r Detailed Hyd r o log y See T ech ni cal Appendix and Work M ap ...... Collection System ...... Boundary Proposed Storm Pipe --UDFCD Study Recommendations .. ___ [ 3900-03 ) Green Valley Ranch West .................... # NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. [ 3700-02 ) Existing .---. Proposed Detention -+-Existing Transit Line Basin 3 9 0 1 -0 2 --' Basin Designed Storm Improvement Existing Basin P City and County Boundary G ate way -Existing Surface Flow D Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inch equals 1 ,2ooreet X Disconnect Significant Flooding Location -+--Planned Transit Line counties Denver Storm Drainage Master Plan Page 89

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D e n ver Stonn Drainag e Master Plan Basin 4000-01 (Staple t on We s t Sec tion 10) Existin g Ba s in D escri p tion: This collection system basin kno w n as S e ction 10 on the Stapleton site is a tributa r y to the South Pla tte Rive r a11d is located e ntirel y i n th e City and County o f Den ver The basin consist s of a bout 4 7 6 acres and is currently unde ve loped except for form e r run ways and storage of c rushed concrete Topograph y w ithi n th e basi n i s characte r ized b y generally flat terrain The sutTound i ng area to the north (dow nstream) of the s it e is t h e Roc ky M o untain ArsenaL The basin was loos e l y d efi n e d iu th e 1989 D enve r D rainage Master Plan and u1clud e d a portion o f north Stapleton (south of 561h ) as well as Adams County (west of Section 10) Basin 4400-01 includes all area south of 561h Avenue in accordance with the approve d Drainag e Master Plan for the Stap l eton R e d eve l opme n t site dated March 2001. The r efo r e, th e r e m ainde r of t h i s bas in l ies n o rt h of 56th Avenue and south of6411' Avenue Identified Drain age Prob l e m s / D efic i e n cies: l n genera l th e r e are current l y no trunk sto rm pip e s wi thin th is ba sin. D e pre ss ions b etween the nrn ways captured stom1w ater nmoff. D isc h a r ges from thi s basin into the Rocky M o untain At'Senalmust be limit e d to historic conditions The p[evious s tud y for thi s ba sin was the 1 995 Stapleton Area Outfall SystemsPia11 (OSP) b y Urban D rain age & flood Control District and M c Laughlin Wate r Engineers. w hich set the tbllo w in g disc h arge for existing and d eve l o p e d conditions : Basin 4000-01 Allowable Ut s c harges P ea k Di scha rge f r o m D enve r t o t h e Design 2Yea r 5 Y e a r 10Y e a r 50Yea r 100 -Yea r Rocky M ount a i n Arsenal Point (c f s) (cfs) (cfs) (cfs) (cfs) OSP Existing Conditions 10" 8 11 12 24 29 OSP Developed Conditions 272 72 72 72 76 82 Stapleton Master Plan 282"* 8 10 10 11 11 Reference : Urban Drainage & Flood Control Dis(rio( "stormwater Outfall Systems Plan -Stapleton Area J ul y 1995 *"Reference : BRW. fnc "Sta pleton Infrastru cture Maste r PlanSection 5," March 2001 P ote n tia l I mp rovements: A 1 00-year r e t e ntion fu c i l ity wiU be cons tructed commensurate with development for tlus basin Establishin g new o utfal l s thr o u g h the Ro c k y M o ontain Ars e nal wo uld vi o lat e previous agree m e n ts. Project A: Pond ZD The propo se d land plan calls for more d evelopmen t than pre vio us l y included in the Green Boo k .. and OSP Accordi n g l y, a ze ro discharge lake (Pond Z D ) 1 s p r oposed to fully store runoff from th e 1 00year, 2 4-hour storm Thi s rete ntion basin \\
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v a; i j z 'f.' l I Cl. z V> v !:i :;< l I K ey Map 0 Commerce City Pond 102 68 .6AF 178AF [ 0058 0 1 ) Adams County [ 4 4000 1 ) Adams County [ 3900-01 ) E 64TH AVE __ ) E 56rH1AVE Ladora Lake Southgate Pond Derby Lake [ 3900-02 ) $ N L egen d Basin 4000-01 Stapleton West Section 1 0 -.... Collection System Proposed Storm Pipe Existing Storm Pipe ; Proposed Detention For Detailed Hydrology ...... Boundary Basin Existing Transit Line D City and County Boundary 0 600 1 200 See Technical Appendix UDFCD Study Designed Storm Improvement Existing Basin and Work Map Recommendations --Existing Surface Flow D Potential Inundation Oth M r. :>' Feet Proposed Pipe Area er umclpa Illes 1 inch equals 1 2ooreet X Disconnect Significant Flooding Location Transit Line D Other counties Denver Storm Drainage Master Plan P age 91

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D e n ve r Stonn Drain age Master Plan Basin 4300-03 (Clear Creek-North of 1-70) Existing Syst em Description: Thi s collection system basin drain s to Clear Creek and is generally bound b y R eg i s Bo ulevard on th e so uth Clear Creek o n the n ort h and west and Alcott Street o n th e eas t A 60-i n c h RCP drains int o the ba s in from the so uth from Basin 4309-0 l (Berkeley Lake) and continues through Willis Case Golf Course and th e n a lon g Sh e 1idan Bou levar d to Clear Creek Th e so u t h ern half of th e basin i s located w ithin th e City and County of D e n ve r and drain s to an exis tin g 36-in c h sys t e m in 52nd Avenue Th e north ern h alf i s ou ts id e of th e City and drain s t o the north in to CleaJ Creek The majori ty of th e basin i s r es id e ntiaL bu t also in c ludes R eg i s University and Willis Case G o l f Co ur se Drainage Deficiencies: The 1 2-i nch pip e in Federal whic h co ntinues t o its outfall in Arvada, is und e r s i zed The maj ority oftnmk drain age sys t e ms in th e r es idential p o rt io n s of t hi s b as in are adequately s 1 ze d for a 2 -year event. Proposed Capital Improvement s: Project A: N F e d e ral Blvd. Outfall Replacing the 12-in ch pip e in F edera l with a 24 -t o JO-i11c h 11ne w ith i n D e nver's juri sdictio n will provid e a 5-yea r l evel of serv i ce Extending the syste m t o the north into Arva d a and the outfal l a t Cle a r Creek wi II r e quir e a 30to 48-inch line to b e coo rdinat ed with th e City of Arvada Proje c t B : Clear Creek Outfall Th e exist ing City and County of D e nver stonn drain o utfall in Sheridan Boule var d s h ould be up sized to b ette r co n vey fl ows to Clea r Creek. Thi s is ou tsid e the C i ty and County of D e n ver: h oweve r Denver has a 30 wid e ease m ent for its existing draiJl in Sh e rid a n Boul evard on t o CJear Creek. September 201-/. P ag e 92

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0 Key Map Jefferson County Arvada Arvada .. ,------' ........ .. .. .. .. .... ... . ... .. .. . .. .. NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. 600 1,200 For Deta il ed Hydrology See T ec h n i cal Append i x and Work Map \ ............ ,, : ...... Jefferson County Lakeside ..... Berkeley Lake .... Collection System ...... Boundary Proposed Storm Pipe -Legend Existing Storm Pipe r' -- Proposed Detention -' Basin Rocky Mountain L
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D e n ve r Stonn Drain age Master Plan Basin 4309-01 (Berkeley Lake) Existing Syst em Description: Thi s collection system basin drain s to C lear C r eek and is generally b o und b y Sheri d a n Boul evar d on the wes t R egis Boul evar d o n the no rth 35th A ven u e o n the South and the Rocky Mountain Ditch o n tl1e east A ppr oximately h a l f of the b as i n drains to t h e intersection of Sh e ridan B ou l evard and 1-70 w hil e the oth e r half drain s to the T e nn yso n Stree t and I-7 0 intersection Rru10ff from th ese two intersect i o n s i s conveyed v ia l arge storm drain syste m s around B e rke l ey Lak e and to tl1e n o rth across 1 -70 Curr e ntl y stom1 pipes carry 'ater around B e rkele y Lak e and do not dis c h arg e dir ectly int o t h e l ake. Prop ose d im prove m e nts o ri g inall y re<:omm en d e d in th e 2003 Rocky Mountain Ditch Outfall Systems Planning Study (OSP) included a new 60-inc h R C P t bat wou ld di scharge into the lake an d a U eviate the Sheridan B oulevard and l -70 syste m However th e 2003 OSP was re-studied b y th e City and Co un ty o f D enver in 2005 and the propo sed 60-inch R C P was d etem1ine d to be Unneces sary becau se t11e existin g sys t e m was found t o b e ad e qu a t e. I t s h o uJd b e noted t hat th e lak e was not construct e d as a det e n tion facilit y, but ina d verte nt d e t e nt ion does occ ur. Drainage Defici enc ie s: Th e 2005 O S P re-stud y found the exi s tin g drainag e system to b e adequate basinwi d e. Proposed Capital Improve m ents: B ased upo n tlt e O S P re-studv. there are n o ca pital i mprovements proposed in this basin September 201-/. Pag e 9 4

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Key Map 0 600 1,200 Cree'+ Ciear ............ __.,.,. ....... For Detai l ed Hydro log y See T ec h n i cal Append i x and Work Map .... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Mountain View Jefferson County Proposed Storm Pipe ... UDFCD Study Recommendations NOTE: Trans -basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. Existing ... ---. Proposed Detention -+--Existing Transit Line Basin 4 3 0 9-0 1 Basin Designed Storm Improvement Existing Basin g City and County Boundary Berke I e y La k e --Existing Surface Flow D Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 ,2ooreet Thalweg X Disconnect Significant Flooding Location -+--Planned Transit Line Denver Storm Drainage Master Plan Page 95

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D e n ver Stonn Drain age Master Plan Basin 4400-01 (North Stapleton) Existing Syst em Description: Thi s collection system basin con sis t s of2.468 acres ( 3.86 s quare mil es) and w ill b e mostl y r e -built w i t h the r edeve l opme nt o f Stapleton. Blueprint J) e Jtvet s hows the e nti re b asin with in the City and County of D e nver as an "Area of C h ange.' The p ortio n of thi s b asin wi thin Adams County d oes not r ece i ve or contribute drainage fiom or t o D e n ve r and th e r e for e has generall y been i g n o r e d for thi s s tudy. A ll dra in age from this basin will o utfall to Sand C r eek. Th e m ajo rit y ofNorth Stapleton hi s t orically drained to th e R ocky Moulltain Arsenal to th e n orth. h oweve r t h e creation o f a Sand Creek o u tfall near Quebec and 1-270 c h a nged this flm v p attern. Larg e regional stormwater infrastructure has b een b ui l t recentl y as part ofth e Nmthfie ld s Mall" development T hi s infr astructure includes a 9foot x 7-foo t box c ul vert in 491b Avenue a nd a 66 -in c h pip e in 451h A venu e as well as a 75 acrefoot detention facilit y near Quebec and I-270 Drainage from th e 'No rthficld s Mal l development drain s t o thi s d e tentio11 facility an d t h e n thro u g h t h e ne w outfalllmder 1 -270 to Sand Creek. Curre ntl y dra inage for the undeveloped areas n orth ofl-70 flows to the n o rth into the Rocky Mou nt ain A r se nal Drau.1age from the I -70 corridor and south ofl-70 flows into Sand Creek. Drainage Defici e ncie s: The S a nd C reek floodplain signi fica ntl y encumb ers t h e s it e between Sand Creek an d l70 FEM A Flood I nsurance Rate Map s ( FIRM ) for t he Stapleton site s hows l arge fl oo dpl ai n areas resu lting fro m San d C reek b reaching J evees along the river edge. 1 -70 is a lso s h own as b eing inu nda t e d durin g a 1 00-year flood event in San d C r eek. l11.e San d C r eek floodplain w ill eve ntu ally b ecome m o r e con fin e d via im ple m en tati o n of th e San d C reek Master Plan c h a nn e l im p r ove m ents. The K in g Soopers and Catellus s it es exi s t west of and adjac e n t t o H avana S in ce n o major outfall exi sts toda y for t h e area. I ()()-year r e t e ntion has been constructed. Runoff i s m etered o u t thro ugh s mal l stor m drain s t o aUow t h e basms to dry b etween storms. Proposed Capit a l Improv ements: P ro p ose d cap i tal improvement projects fo r this b as in a r e being con stmcte d as partofthe Staple ton D eveJopment P a r k Creek Met ropo li tan District A number ofpreviolJS stu dies have es t ab lished the framewor k for manag e m ent of storm water a t the site including the Outfall Syst e m s Plan-Stapl e t o n Area ( O S P) p r e p a red b y McLaughlin Water Enginee r s for the C ity and County of D e n ve r an d the U rba n D rai n age & F lood Control Di s t r ict i n 1 995 the Stapl eton Sitewide Master Plan prepared b y T urne r Colli e a nd Br ade n in 1 996 the Infrastructure Master Plan prepared by BRW. In c in D ecembe r 2000 a nd approve d by D e n ve r Wastewater in April 200 L. and the North Stapleton Ma:'iter Plan prepared b y Matrix Design Group In c ., and approved b y D enve r Wastewater in D ecember 2006. The most cur r en t docw11e nts a r e the North Stapleton Infi ast.Jucture Master Plan Major Amendment No 2 prepared b y Matri x D esign Group In c in J an u ary 20 1 2 a nd t h e Filing 42 North Staple ton Final Drainage R eport p repared by Matrix D esig n Gro up Inc in March 2013. S ub sequent to t h e 20()8 Storm Ma s ter Plan a d ditional fi lings (25 36 37. 39. 41. 42, 43 and 44) h ave been submitte d and approved b y D enver D eveJopment Services. September 20 1-J Page 96

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K ey Map 48AF 0 700 1 400 0 [ ooss0 1 1 Adams County Co mmer c e C ity For D eta il e d Hy d rology See T ec hni cal A pp en dix an d Wor k M a p 1 4000 -01 1 Adams County .... Collection Sys tem ...... Boundary Proposed Storm Pipe --UDFCD Study Recommendations ".f> ..! 'e" "" ."!-._. .. ,. ..., ,. / 4! .. ( 390 10 1 ) '!> ( 44 00 03 ) Ad oms County ( 44 00-0 4 J Aurora Pond #220 ., ( 4 4 0 1-01 ) .. #222 .-- / .. I Bluff Lake Existing ;---. Proposed Detention -+Existing Transit Line Basin 4 4 0 0-0 1 Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatl'on g City and County Boundary N 0 rth s ta pIe t 0 n -E x isting Surface Flow L__j : Oth e r Municipalities Feet Proposed Pipe Area 1inchequa 1s 1 ,4ooreet X Disconnect SignificantFioodingLocation -+PlannedTransitline Denver Storm Drainage Master Plan P age 97

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D e nver Storm Drainag e Master Plan Basin 4400-02 (Quebec Corridor) Existing System D-escription: This collection system basin i ncfud es a mix of industrial and re side ntial land uses to t h e west of Stapleton along Quebec. It consists of2,822 acres ( 4.4 1 square miles) and is fi.11ly built-out w ith older n e ighb o rhood r es id ential in the upper reaches and commercial in the lower reach es. Blueprint Dem, er s hows the e ntir e basin as an ''A rea of Stabi lity", infening tl1at Ba s in 4400-02 is not an area of future land use change. All drainag e fiom tl1is basin o utfalls to Sand Creek o r the Sou th Platt e River Drainage Deficiencies: The existing drain age sys tem has capacity to convey less t han the l'-year s torm event to the outfull. Rainfa ll mnoff in excess oftl1e stonn drain capacity has a hist01 y of pondin g in th e sump and flat areas. S pecific deficiencies includ e: Dminage to the so uth ofSmitl1 Road r equires improve d conveyance via Dahlia Street ; the l ack of an adeqt1ate outfall causes ponding of up to 4 feet in d epth and c reation of an urban floodpl ain alo n g E Smith Ro a d A locali ze d sump conditi o n exi sts at M artin L uther King Jr. B o ulevard and Eudora Street w ith flooding r e port e d as earl y as the 1960' s. A local ized sump conditi o n i n th e 3300 block o f N Olive Street an d a 1 2-inch di a meter storm drain cau ses wat e r t o pond up to the h o m e foundations Potential Inundation Areas: An ex1e n sive area of flood hazards have been ide nt ifie d within Basin s 0060-01 and 4400-0 2 r elate d primaril y to pondin g behind railroad tracks, 1-70 and oth e r swnps in the lower porti o n s of each basin as well as gen e r a ll y Wlde rsiz e d stom1 dra in age facil ities resulting i n street flo"v d e pths g reater than tl1e City" s drainage criteria. H ydraul i c anal ys i s of the basin indicates tl1e pote11tial for sto rm wat e r inundation grea ter tl1an 1 2 -in c h es deep in th e gutter t o occur at the tollowing l ocations : N i agara Stree t between 1 9 t h A ve nu e a nd 26th Avenue Monaco Parkway b e tween 36' Avenue and 39th Avenue Niagara Stree t between 35th A ve nu e and 36th Avenu e 36th A venue b e t ween N iagara Street an d Mon aco P arkway Ivy and I vanhoe Streets b e tween M artin Luther King Boulevard and 35th Avenue H o ll y Street b etwee n 35th A ven u e and 39th Avenue 39th A ven u e f rom M o n aco Parkway to H o ll y Street Jasmine Street between 26' Avenue and 29th Avenue F o re s t Street fro m 39th Avenue to Smith Road Dal1lia Street fro m Martin Lu t her King Boulevard to 38tb Avenue Along S mith Road fr o m Grape Street to Colorado B o ulevard Eudora Street from 29tl1Avenue to 38'h Avenue S mith Road b e tween Dahl ia Street an d Forest Street Proposed Capital Improvem ents: Drainage improvements propos e d in thi s plan primari l y attempt to achie ve t h e m inimum p erfonnance o bjectives for resid e ntial and commercial a reas (2-and 5 -year syste m capacit i es) es tabl is h e d for the Denve r September 20 1-J s t ormwat e r program. Proposed cap ital improve m ents were developed durin g t h e Atkins drainage study titl e d Sand Creek (4400-02) and Uppe r Park Hill (()()60-(JJ, 4400-02 & 4500-01) Final /)rainage Study. d ate d J u l y 2011 Th e improvements propo se d b e low are taken directl y from tbe 2011 study for the minor 2-and 5 yea r design frequency (Altemative 1A) AdditionaUy a 100-year m ajor-even t design sizin g alte mative is includ e d f r o m tl1e study (Alternative I B). Pro rec t A : 39!h Avenue/Elm Street Improve m ents The existin g syst e m a lon g Eudora Street will b e join e d b y a late ral in 35 th Avenue and w ill b e up s i ze d from a 48-inc h pipe to a 60-in c h pipe from 36th Avenue a nd Elm Street t o 39t h Avenue and Gra p e Street. P roject 81: 38th Avenue and H o ll v Street Collector A new stom1 drain n etv,;ork is need e d to convey the 2-year flows from Proj ect B238 h Aven u e and H olly Street Co llector Ext e n s i o n. and lo cal s ub bas in s t o Pr o ject D 3 811' A venu e inte rc epto r A 60-in c h to 72 -inch trunk lin e i s proposed along Krameria Street 35th Ave nue. Magnolia Street, and 29th Avenue with a few additional coJiectio n l ate ral s propo se d Pro tec t B2: 38th Ave nu e and Holl y Street Collector E:\.1ension T h i s proposed syst e m e:\.1end s from Pro j ect Bl. Flows in th e exist in g 48-inch pipe at 26th Aven1.1e and Magnolia Street w ill be rout e d to a proposed 4 8 -in c h pipe along Magnolia Stree t and connect e d to tl1e 66-inch t r unk Jine in p rojec t Bl a long Magnolia Street Th e existing 48-inch pipe a t 26th Avenue an d Magnolia Street w ill the refore b e r e lieved of capacity resulting in the e ntir e existing syste m a lon g Jasmine, I vanhoe, and Holl y Streets t o b e capable of handlin g tl1e 2-year desi g n flows. Additional collection syst e m s are proposed in th e uppe r basin along New-port Street 22nd A ve nu e Montview Boulevard, ahd lib Aven u e. Project C [ vanhoe/lvv Street Colle<:tor Lateral s This project includes minor lateral syste m s to inc rease the collection cap ac i ty of the existing syste m a l o n g Jasm i n e I vanhoe and Holl y Streets Protect D : 38th Avenu e hlte rccptor A new 5 yea r st o rm drain syste m i s n ee d e d in 3811' Avenue fro m Monaco Parhvay t o Holl y Street witl1 sizes rang in g from 1
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Key Map \ County I \ 16.3AF Northfield Water Quality Pond 75AF (/) 0:: 0 2 ...... I UJ ..J Q. (/) UJ I I I c:: I gl) i NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. [ ooG0-01 1 0 700 1,400 For D eta il ed Hydrology See T echn i cal Appendix and Work Map ..-. Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm P i pe ... UDFCD Study Recommendations -N QUEBEC S T L egend Ex i sting Storm Pipe Designed Storm Improvement --Existing Surface Flow 0:: 0 [ 4401 -0 1 1 [ 4500-01 1 N COLORADO BLVD r' Proposed Detention -.J Basin Existing Basin -+-Existing Transit Line D City and County Boundary ...... 11 Potential Inundation : Other Municipalities UJ UJ .... A 39TH AVENUE/ELM STREET IMPROVEMENTS : $4,543,533 .... B1 -38TH AVENUE & HOLLY STREET COLLECTOR : $9,435,897 .... B2 38TH AVENUE & HOLLY STREET COLLECTOR EXTENSION: $13,020,037 .... C IVANHOE/IVY STREET COLLECTOR LATERALS: $2, 182,981 .... D 38TH AVENUE INTERCEPTOR: $4,319 664 .... E 39TH AVENUE INTERCEPTOR: $3,320,161 .... F2 UPPER PARK HILL OUTFALL: $8,811,046 Basin 4400-02 Quebec Corridor Feet Proposed Pipe L-....J Area _____________________________ __________ jf ___ s ig n ir ic a _nt_ F Ioo __ d in g L oc a tio n ________ P Ia n n e d T ra n _sit_ L i n e __ ____________________ Page 99

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D e n ve r Stonn Drain age Master Plan Basin 4400-02 (Quebec Corridor) (Alternative 100-Year Basin) Proposed 100 Year Alternative Capital Improvements: Proj ects A. B I 82. C. D E & F2 The l 00-ycar alternative for this basin shows larger stoun drain pipe sizes and some c han ges iu stonn drain aligtunents In order to capture more runoff in the u nderground stom1 drain system and reduce s urfuc e runoff depths in the streetto 12-inches deep in the gutter in accordance witl1 D e nver' s stree t depth criter ia. These alternatives are based on analysis done in the Jul y 2011 Scmd C reek (4400 02) and Upper Pc"k Hill (006001, 44()0-02 & 4500-01) Basins Final Drainage Study by Atkins September 201-/. Page 100

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Key Map \ County I \ 16.3AF Northfield Water Quality Pond 75AF U1 0:: 0 2 ...... I UJ ..J Q. (/) UJ N QUEBEC S T 0:: 0 I I ; i I 0) gl) ; t e NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. [ ooG0-01 1 L egend ..... Collection System Existing Storm Pipe r --. Pro posed Detention Proposed Storm Pipe ...... Boundary 1.-.-.J Basin [ 4401 -0 1 1 [ 4500-01 1 0 700 1,400 For D eta iled Hydrology See T echnical Appendix and Work Map -+-Existing Transit Line D City and County Boundary t:-t Topographic Basin --UDFCD Study Designed Storm Improvement ..J' Boundary Recommendations Exi sting Basi n 1 : 1QQ.yr Sub Collection --Existing Surface Flow D Potential Inundation : Other Municipalities UJ UJ .... A 39TH AVENUE/ELM STREET IMPROVEMENTS: $7,816,248 .... B138TH AVENUE & HOLLY STREET COLLECTOR: $14 207,693 .... B2 38TH AVENUE & HOLLY STREET COLLECTOR EXTENSION : $17.158,378 C IVANHOE/IVY STREET COLLECTOR: $13,895,077 .... D38TH AVENUE INTERCEPTOR: $8,294 ,138 .... E 39TH AVENUE INTERCEPTOR: $3,477,128 .... F2UPPER PARK HILL OUTFALL: $11, 661 937 Bas i n 4400-02 1 00yr Alternative Quebec Corridor Feet System Boundary X Proposed Pipe Area _____________________________________________ _______________ ______ s ig n ih c an t F Io o d in g L _oc_ a ti o n __________ _________________________________ Pag e 101

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D e n ve r Stonn Drain age Master Plan Basin 4400-03 (Stapleton) Existing Syst em Description: Thi s co Jlection sys tem basin consists of967 acres (1.51 s qu are miles) and i s b ei n g ot will be, nearly co mpl e t e l y re-buil t \Vith the r edevelop m e nt of S tapl eton Blueprint Denver s h ows th e portio n of the basin wes t o f Q uebec Street as an ''Area of Change All drainag e from this b asin will outfall to S
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Key Map 0 600 1.200 Commerce City Adams County [ 4400-02 ) For D eta iled Hydrology See T ec hni cal Appendix and Work Map 1(/) 0 u <1: 2 0 2 2 .... Collection System ...... Boundary Proposed Storm Pipe --UDFCD Study Recommendations A !! j :: ... 1 08.196 ... ll [ 4401-01 ) [ 4400-01 ) [ 3901-01 ) .... _________ ;"'""' Pond #220 Pond #223 Pr o posed Pr o j ec t s [ 4400-0 4 ) Bluff Lake ... ASTAPLETON-04: $762,411 .,. C-QUEBEC ST OUTFALL: $8,164,283 Existing .-I Proposed Detention -+Existing Transit Line Basin 4 4 0 0-0 3 '----' Basin Designed Storm Improvement Existing Basin g City and County Boundary s ta pIe t 0 n -Existing Surface Flow c:::J Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1inchequa1s1 ,2 ooreet X Disconnect SignificantFioodingLocation -+PlannedTransitline Denver Storm Drainage Master Plan Page 103

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D e n ve r Stonn Drain age Master Plan Basin 4400-04 (East Stapleton) Ex isting Syst em Descr ipti on: This collection system basin consists of 1.219 acres ( 1.90 square miles) A portion of this basin i s wit hin Aurora Th e D e nver portion (Stapleton site and north of Sand Creek and south of 1 -70) is an Area of Change .according to Blueprint Denver" The Stapleton redevelopment site is scheduled to be completel y re built by the developer Forest City All drainage from this basin will outfall into Sand Ct'Cck. Th e area north of Sand Creek sout h ofT-70 was divided b y tl1e rai lr oad tracks along S mith Road The area nortl1 of Smith Road currently drains to an existing 84-incb outfall at Havana Street. The area south of Smith Road drains to open channels direct l y to Sand Creek Currently ther e are only three known outfalls into Sand Creek withi.u this basin : 72-inch from A u rora from t h e south through the Stapleton site 84-inch in Havana from the north collecting drainage along Railroad Track and Havana Open channe l in A uror a fro m the north Type B soils are assumed south of Sand Creek for h y drologic calculations and detention design Drainage Deficiencies: Drainage on the Stapleton site i s currently informal with few storm drains. relying upon infiltration evaporatio n and s h eet flow to drain the site to San d Creek A 72-inch stom1 drain fro m Aurora cunentl y flows north though the Stapleton si t e and discharges to Bluff Lak e Thi s 72-inch pipe. can convey onl y mnoff up to the 5-year event. The 1 00-yeat flow will s plit out of this basi n by flowing in a n open channe l constructed along the sou th ern Stapl e ton batmdary at 261h Avem1e. and discharging i nt o Westerly Creek Dra inage from the D e n ve r jail a nd other co mm erc i al/ind u strial prop e rties between ra ilroad track and l -70 i s co n veyed to Sand C r eek in the exis tin g 84-inc h pipe l11is pipe has capac i t y for th e 2y ea r d i sc harge. Runoff in excess of a 2-ycar even t will backup against Smith Road and the railroad tracks. Drainage from th e 1-70 corridor flO\YS in a stonn pipe system parallel to 1-70 int o Sand Creek Propos e d Capit a l Improvement s: The framework for stonnwate r management at the S t apleton s it e has been set b y the Systems Plan Stapleton Area (OSP) prepared by McLaughlin Water Engineers for the C i ty and County of D enve r and the Urban Drain age & Flood Control Di strict in 1995 The Infrastructu re Master Plan prepa r e d by BRW, Inc. in December 2000 and approved by D enver Wastewater in Apri I 200 1 "vas prepa red to eval u ate infrastmctur e n eeded to suppo r t redevelopment of th e fonner Stapleton International Airport. Redevelopment will inc lud e drainage infrastmcttlre to convey t h e full l 00-year stmm to Sand Creek In a d dition regional water quality treatment w m be provided in acco rdan ce wit h U rb an Drainage & Flood Control District Volume 3. Project A: Stapleton 06 To ach i eve a 5-yea r system for tl1e commercial area north of S mith Road and to preserve the existing stonn d rain in tl1e area, a new outfal l is proposed a l ong th e D e n ver Count y lin e at Lima Str eet. Thi s new 1 2-foot x 4-foot bo x culve rt will pro vide the additional outfal l capacity for s u bbasins 10 11, 20 2 L 40 and a pottion of subbasin 30 to be protected from ponding up to a 5-year eve nt September 2014 Ptojoct C: Stap l eton 08 This project connec t s to Project A and e-:-.iends the l ateral lletwork further into t h e basin. Existi n g 48-and 54inch l ate ral s will be upsized to 72and 84-inch pipes respectively to provide a 5-year l evel of service Page 1 04

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K e y Map 0 ...... ___ W/1',.,,. [ 4400-0 1 1 NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems. not proposed drainage improvements. Adams County Auro ra 0 6 0 0 1 .2 0 0 For D e tai l e d Hyd r o log y See T ec h ni c a l Appendix an d Work M a p ...... Collection System ...... Boundary 1-1 Topographic Basin Proposed Storm Pipe --UDFCD Study Recommendations -L egend Ex i sting Storm Pipe .... ___ E 33RD AVE ( Otsson 1 0) ....... E 26TH AVE [ 3 901-01 1 -----Adams County Adams County Aurora Pr o posed Pr o j ec t s ... A STAPLETON 06:$7,743,659 ... C-STAPLETON-08:$19, 114,506 ;---' Proposed Detention -+-Existing Transit Line Basin 4 4 0 0-0 4 Basin Existing Basin g City and County Boundary East s ta pIe t 0 n "' Boundary Designed Storm Improvement E x isting Surface Flow 11 Potential Inundation : Other Municipalities Feet Proposed Pipe L__J Area ___________________________________________ _____________ x ____ D is c o nn e c t _______________ ____ s ig n ir ic a _nt_ F Ioo ___ d in g L oc a tio n ____________ P Ia n n e d T ra n sit L in e ___ ______________________________ P age 1 05

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D e n ve r Stonn Drain age Master Plan Basin 4401-01 (Westerly Creek-South Stapleton) Existing System Description : Thi s collection s ystem basin drain s to West erly Creek and is generall y bOlUld b y Quebe c Street o n t h e west. Montview Boul evar d on the south Peoria Stree t on the eas t and Sand Creek/Martin Luth e r J(jng Boulevard on the north The p ortion ofthis basin in D e n ver i s locate d wi thin the Stapleton Redevelopment propert y, with th e exce ption ofthe south east portion ofth e b as in l ocate d in A urora TI1e b as i n size i s 3 0 1 s q uare mil es. Most o f the b asin i s compri se d o f resid e ntial n eig hborhoods w ith commercial / retail areas located near th e art e rial road ways. Blueprint Denver identifies the portion of t h e drainag e basin w i t hin D e n ve r as an Area of Change w 1th t h e exce pti on of a sma ll exi s tin g res idential area south of E 23rd Avenu e and wes t of S y ra c u se. Th e p o ttion of th e basin in Stapl e ton was reconstmcted b e t wee n ye ars 2 0 00 t o 2005 w ith I 00-yea r con veyance s ys t e ms. Each outfall includ es a r egiona l w ater qualit y ba si n a t th e end of pip e befo r e dischar g ing into W esterl y Creek Wate r quality ba sins arc locat e d on the wes t bank at 23rd Avenue 26th Ave nu e 291h A ve nu e M a rtin Luther K ing Boulevar d and 33rd A venue Water qu ality basin s are located on the eas t bank at291h Ave n ue and M artin Luther King Boul evar d A 20.4 acr e-foo t regi o nal cons truct e d wetland d ete nti on b as in capturin g runoff from 1 8 1 acres is loc a t e d wi thin the cast-West Linea r Park' at Stap le t o n located alo ng 26th A ve nu e at Central Park B o ulevard. The p ortio n of the basin in Aurora has historically drain e d to BluffLake via a 72-in c h s t o rm drain Howeve r thi s p i pe h as capac i ty for on l y the 5 yea r s t om1 even t and flows in excess o f th e c apacjty ha ve h istorically been trapped against the fonncr Stapleton Airport runways and direct e d in an open channel a l o n g 26th A venue to Westerl y Creek. The 26th A venue channe l was studied as a part of Stapleton Plannin g Area 4 and has b ee n improved to ad equate l y convey th e full 100-yea r stom1 to West erly C r eek Drainage Deficiencies: All drain age probl e m s wi thin D e n ver are b eing account e d for in the r edevelopmen t of Stapleton O ve rflo w from Auro r a s s y stem i s f o llowing th e hist oric path and i s b e ing direct e d to West erly Creek in an improv e d c hann e l al o n g 26lh Avenue. The City of Aurora is replacin g th e Montvicw Boulevard bridge over W csterly Creek to remove a larg e number of homes fr-om the tOO-year floodpl ain. Modifi catio n s of a pproximat ely 1.200 feet of W esterly Creek downst ream of the bridg e w ill be required as part of the project Proposed Capital Improvements: Project A: Stap le ton 09 Thi s project include s capital imp rove ments b y the d eve l o per for I 00yea r storm syste m s throu g ho u t out the S taplet o n d eve lopment URS Compa n y was in th e pro cess of d eve loping a s t onn wate r m as t e r pla n for the C ity o f h o .. veve r r eco mm e nd a tion s wer e not availabl e at the tim e this stud y was updat e d Sept e mber 201-/. Pag e 1 06

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Key Map [ 4400-031 E 26TH AVE E 23RDAVE Pond 1156 Adams County w (.) z w a: 0 ..J u.. [ 4401 -02 ] 14400-01 1 1(/) a: w > 0 z <( :I: Adams County [ 4400-04] Aurora 13TH AVE 12TH AVE 22NDAVE 17TH AVE Proposed Projects ... ASTAPLETON 09: $1,962,249

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D e n ve r Stonn Drain age Master Plan Basin 4401-02 (Westerly Creek -11th Avenue to Montview) Existing System Descl"iption : Thi s collection s ys tem basin drain s to W esterly C reek and is generall y bOlUld b y Queb ec Street o n t h e west. Montv iew Bou levar d on the n ort h P eoria Street on th e east and 1 1 tb A venue on the so uth Th e basi n is Joc ate d b etwee n t h e Stapleton R e d eve lopm en t prop erty an d the Lo wry R e d eve lopment prop erty Th e wes t portion oftl1e basin i s in D e n ve r an d th e eas t p ortio n i s i n Aurora with Westerl y Creek runn i n g sou th to north down the cent e r of the basin Th e b asi n is co mpri sed o f r eside nti a l n e ighborh oo d s w ith co mm e r cial/retai l areas locate d n car the arterial roadwa ys. There are severa l existing stoon drain syste m s in ro a d ways that disch a r ge in thr ee locatio n s dir ectly to Westerl y Creek. A 15-inch pip e in Ricnthof e n Pl ace w ith an existing capacity of 6 cfs drains 42 acres with a 5-yea r ru11off of 39 cfs. A 48-inch pipe in 13th Av enue w ith an existin g capacity of 80 cfs drains a 1 30 acre area wit h a propo sed 5 year nmoff of 14 6 cfs. A 60-inch p i p e in Montvicw Boul evard wit h an exist in g capacit y of 1 38 cfs drain s 290 acres w ith a 5 yea r nmoff o f 299 c f s Kiowa Engineering Corporation compJcte d the We s terly Creek (Downstream of W es t e rly Creek Dam) Major Drainageway Plan und e r t h e dir ectio n of t h e Urban Drain age & flood Co ntrol Di strict and the City and Cotmty of D e n ve r in 20 l 0. U RS Compan y was in th e process o f d eve l oping a sto nn w ate r maste r plan for the City of Aurora ; ho weve r recommendations were no t av ailabl e at the tim e thi s s tud y was upd ate d. Dl'ainage Deficiencies: Th e 1 5-inch pip e draining B asin 2 10 has a capacit y of 6 cfs. w hiJe the 2-year flow to the p i p e i s 20 cfs. The 60-inc h pip e drain ing Basins 260 an d 261 has a capac ity of 138 cfs w hil e th e 2-yea r flow is 1 64 cfs. Proposed Capital Improvements: This b asin requires improvem ents primarjl y to the outfalls since th e lat e rnl networ k is c urr e ntl y suffic i e nt wit h the n ew pip es d es i gne d b y D e n ve r Proj ec t A: E Colfa..-x Ave Outfall Colfax A venue i s a m q jor transportation corridor thro ugh the basi!l wit h few existing s t or m drain age facilities An impro ve m ent i s required at th e o u tfall t o Weste rl y Creek to convey localize d stonn runof[ Proj ec t B : B 17' h O u tfaJl Th e combi ne d flows of Basin s 260 and 261 ex.ceed th e allowable ca pacity of th e 60 -in c h p1pe in Montvicw B o ul evar d A new 54-i n ch outfall in 1 ih Avenue from Uint a Street to Westerl y Creek w ill drain 1 3 1 ac res from B asins 26 1 and 260 .. Tb e 2-year tlO\ V from th e new drainage a r e a w ill b e 83 c f s w i th th e 80 % ca pa c i ty of a 54-inc h pipe at 0 .5% o f 112 cfs. Proj ec t E Richthofe n Pl. OutfaJl The 1 5-i n c h outfaJI in Ric hth ofc n Place n ee ds to be improved t o convey a 2 -year flo w o f 20 cfs. Upsizing the pipe to 30 -inch from V e rb ena Street t o W es terl y Creek w ill provide an 801Yo capacit y of28 cfs at a s lop e of0.7%. September 201-/. Pag e 108

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a; 1! E l c..' z "' v 0 !?) l J Key Map E MON T VIEW BLVD E 17TH AVE E COLFAX AVE ..... (/) >-0: j 2 Detention Facil ity #152 ) l Adams County Arapahoe County [ 4401-01 ) .,. A E COLFAX AVE OUTFALL: $856,071 ... B-E 17TH AVE OUTFALL: $3,113,784 $ N Legend Basin 4401-02 11th Avenue to Montview ..... Collection System Proposed Storm Pipe Existing Storm Pipe ;- Proposed Detention For Detailed Hydrology ...... Boundary '----' Basin Existing Transit Line D City and County Boundary f 0 600 1 200 See Technical Appendix -e-UDFCD Study Designed Storm Improvement Existing Basin o d W k M t-1 Topographic Basin Recommendations 5 an or ap Boundary -Existing Surface Flow 11 Potential Inundation Ot M "' L__J : her unicipalities l1' Feet Proposed Pipe Area linchequa1s1 2 ooreet Thalweg X Disconnect SignificantFioodingLocation Denver Storm Drainage Master Plan Page 109

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D e n ve r Stonn Drain age Master Plan Basin 4401-03 (Westerly Creek-Lowry) Existing Syst .em Description: Thi s collection sys tem basin drain s to Westerly Creek and is generall y b ow1d b y Que b ec Street o n t h e west. I I th Avenue o n the n ort h H avana Street/Peoria Street on th e eas t and Alameda Avenue o n th e south A significant porti o n of the b asin i s w ithin the Lowry R e d eve l o pment prope r ty in D e nver_ and the eas t ern portion oftl1e b asi n 1 s in Aurora. TI1e portion of the drainag e b asin w ithin D e n ver i s id en tifi e d as an 'Area of C hange" in Blueprint J)enver. Westerl y C r eek run s fro m sou t h to n o rth down the ce nt e r of t he b asin Westerl y Creek Dan1 p o nd ( 500 year d e t e ntion capacity) is Jocate d in the southeast comer of the basin and Kel l y R o ad Dam (100year detention capacity} i s lo cate d in the north The basin is compri sed o f a tnL'{ of r esi d ential neighborhoods commerc ial areas golf cours e and o p e n space. The red eve lopm ent o f Lo wry includ e d 1 00-year capacity s tonn drains. The h y drology for thi s basin was stud ied in de tail in a r eport titled Low1:v Master Drainage Plan (December 1998) t o design 1 00year capac i t) systems. The Westerly Creek Drainagewa y Update (Downstream of Westerly Creek Dam) Major Drainag e way Plan (MDP) was completed b y Kiowa En gineering Corporation in July 2010. The MDP r eexamined th e h y drology i n tl1is a r e a and modified it. The maj01 : drainage b as in s we r e also defined b y th e MOP. The discharge from W esterly Creek Dam i s a 48-incJJ RCP storm drain w ith a 7-inchW x 48-inchH restrictor o rific e. An o pen c hann e l of Westerl y Creek exists b e tween Westerl y Creek Dam and Kelly Road Dam to ca ptur e and co n vey l ocal tUllOff. Most Lo wry stonn drain s o utfall to W ester l y C reek north oftl1 e 61h Ave nu e alignment. Regi onal water q uality treatment occurs w ithin Westerl y Creek Dam an d Kelly Road Dam Drainage Defici e ncies : All drain age probl e m s wer e accmmtcd for in th e redevelopment o f Lo w t y per the Lowry Mast e r Dmin age Plan (December 1998). Proposed Capital Improvements: No capit al improvements are proposed for thi s b asin. T11e developer i s pro vidi n g l 00-year s t o rm s ys t e m s throughout out the Lowry d eve lopment. September 201-/. Pag e llO

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e I 0 : iii ;1 E g. :; I c.. :; 0 Vl I Q N "' 8 D g. l c.. I e g e' 0 ;:;: K e y Map [ 4500-041 ., 600 1,200 Feet 1 inch equals 1 200 feet E 1ST A V E 1-C/) u IJJ m IJJ :::> 0 C/) For D e t a il e d H y drology See Technical Appendix and Wor k M ap 1-C/) [ 440 1 -02 1 ..... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Thalweg I \ -... ,.,. .. !; .. Proposed Storm Pipe .... UDFCD Study Recommendations X Proposed Pipe Disconnect .. .. '> '
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D e nver Stann Drain age Master Plan Basin 4401-04 (Westerly Creek-South of Alameda) Existing Syst em Description: This collection sys tem basin drain s to Westerly Creek and is generally b olUld b y Alameda Avenue on t he n o rth Havana Street Ol1 the east and E vans Avenue on t h e sou t h The basin i s located so uth of t h e Lowry R e developm ent prop e 1t y The northern p ort ion o f t h e basin is in D enve r and the remainder is Jocated in Aurora but drain s into D e nver The Hig h Lin e Canal runs wes t to eas t across th e n o 1 t h e m p011io n o f the basin. The bas in i s compri se d of a mix of r es id e ntial n e ighb o rhoods w ith comme r c ial / r e tail a reas located near the a r terial road ways. The two maj o r exist in g stonn drain tmnk systems a r e J ocated in Havana Str ee t and Dayton Street, draining a o f the basin to the Westerl y Creek Dam p o n d There are several additional pipes crossing Alameda conveyin g flows from th e south to t h e Westerl y Creek D a m p o nd area. B as in s 410, 411 a nd 4 1 2 dra. in v i a storm drain to th e privatel y-owne d Windsor Lake, w hich the n d i scharges into t h e Hig h Line Canal Dtainage Deficiencies: The 54-inch sto rm pipe draining Bas in s 4 1 0. 411 and 412 has the capac i ty to convey approximatel y 108 cfs, w hil e t h e 2-year and 5-year flows are 239 cfs and 379 cfs, respecti vel y at D esign Point 113 The 72-i nch stoun drain in Dayton Street has the capacity to convey approximately 255 cfs, w hil e the 2-year and 5year d es i g n flows for t h e system are 35 4 cfs and 560 cfs respectivel y. Ponding occur s at the inte rsect io n of Missi ss ippi and H ava n a. Th e 66-inch stom1 d r ain in Havana Street has the capac ity to convey app r oxi m ate l y 238 cfs, w hil e t h e 2-yea r an d 5-year design flows for t h e syste m are 267 cfs and 431 cfs respective l y at Desi g n P o in t 420. Proposed Capital Improvements: Tbj s b as in r equires impro ve m e nt s p rima r il y to th e outfalls since th e l ate ral networ k i s ctmently ade q uate At th e tim e o f t hi s Storm Drainage Master Plan u pdate th e UDFCD, i n coordin a ti o n w i t h th e City of Aurom and th e City and County of D e n ve r. is conduc t i n g a Creek (Up s tr eam o f Westerly Creek Dam) Major Drainageway Plan l11e stu d y i s being prepare d b y C H 2MHi ll a nd w ill evalu ate regional drainage n ee d s in this basin 1b.is may result in the a l te ration of proposed capital improvem e nts. Project A: S. Alton St. Improve m e t Us The 54-in c h outfal l near Mississ ippi and Alton needs to b e improved to cotwey a 2 -year flow of 239 cfs. Addin g a new 66-inch pipe in A lton from Mississippi so u t h and c01mecting the existing system from Aurora t o thi s new pipe w m h e lp allevia t e the flows from t h e existing 54-inc h lin e The existing 54-inc h Jin e wou ld contin u e to co n vey flows trom 64 acres. with a 5-year flow of 85 cfs. The new 66-inc h line w ill convey flows f r o m the remaini n g 253 acres, mostofwhic b i s in Auro r a. Adding a l arge region a l detention b asin in Amara would greatly help reduce the flows and pipe sizes need e d in Denver. P ro ject B : East Mississippi D e t ention The 72-inc h outfall in Dayton Street needs to b e improved to convey a 5-year flo w of 560 cfs. One option would be to inc rease the p. ip e s iz e to 90-in ch from Mi ss i ssippi to th e o utfall TI1e preferred option (s hown o n th e adj ace nt p age) is t o provide d e t en ti o n at the vacan t lot in th e southeast comer of Mississi ppi and D ayto n This parcel is located within Aurom. September 20 I-I Project C S. Havana St. Outfall The 66-inch o utthll in Havana Street needs to be imp roved to con vey a 5 -year flow of 431 cfs. L1 addition. frequent pondi n g occurs at the intersection of Mississippi and Havana. Increasing th e existing pipe to a 90-inch pipe and extending it up Havana to Mississippi woul d provide 5-year conveyance and alleviate the floodi n g at th e Missi ss ippi and Havana inte r sectio n Page 112

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K ey Map 700 1,400 Feet 1 inch equals 1,400 feet Arapahoe County S DAYTON ST ( 4401-03 1 / / ,./., *,. I Creek Dam Pond For Detailed Hydrology See Technical Appendix and Wor k Map ...... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Thalweg Arapahoe County Proposed Storm Pipe UDFCD Study Recommendations X Proposed Pipe Disconnect Arapahoe County -L ege nd Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location r Proposed Detention Basin Existing Basin 11 Potential Inundation L___J Area Planned Transit Line Existing Transit Line D City and County Boundary .... : Other Municipalities D Other Counties NOTE: Thi s a rea is currently being studied by C H2MHill f o r the UDFCD w ith fin a n cia l participat i o n b y Denver and Aurora P lea se see Westerly Creek (Upstream of Dam) Major Drainageway Planning (MOP) Study for additional improvements whic h may be proposed in the MOP. Pr o p ose d Pro j ects / l \ A SALTON ST IMPROVEMENTS: $677,040 .... CS HAVANA ST OUTFALL: $11,682,413 Basin 4401-04 South of Alameda Denver Storm Drainage Master Plan P age 113

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D e n ver Stonn D rainage Master Plan Basins: 4500-01, -03, -04 (Montclair) Existing S ystem Description: The Mo n tclair Collec t ion Svstem B asin contains a total land area of approx imatel y 6 ,039 acres and inclu des planning B asins 4500-01. o3, and 0 4 The up stream basin l imit of t h e fu ll y -developed basin is located at t h e southeast at the Fairmont Cemeterv located near the intersection of Sou th Quebec Street and East Alameda Avenue Land use varies wit hin the basin from primaril y reside n tial in the upper reaches to comme r c i al and industrial in the lower reaches. City P ark a n appr oxi m ate l y 320 acre urban park that contain s the D enve r Zoological Gardens the D e n ve r MLtse um of Nature & Science and th e C i ty Park Golf Course is l ocate d ncar the ce nter ofth e planning basin. Stonnwate r runoff flo ws north west thro u g h th e basi n in an e)l.1:e nsive sys t e m of existing stonn dra i ns. Su r c h a rged flows arc co n veye d overland v i a t h e n c tvvork of City streets. The basin di sc h arges to d1c South Platte Rive r through a m a i n o utfall a l 0 x 1 0 ( 1 20in c h x 120-inch) r e inforc e d con c r e t e box c u l ve tt, locate d in G l obe v ille P a rk a ppro x imatel y 500 fee t n 01t h eas t o f th e inte rsectio n of 38th Streect and Ark in s Court A second s m a ller outfall (24-inc h) pipe di sc h arges to th e South Pl atte Ri ve r near 38th Street. Sec the write up for Basin 4500-03 for the results table showing t h e exi sti n g con dition h y drologic analysjs. Drainage D e fici e nci es: A p proximate l y 93,637 feet of existing storm drains were tde nt ified as dcfictcnt w ith about 40% ofthem ha v in g less than 50 p e r cent of the r equired desig n capac ity. O n average. existing pipe systems located w i thin th e Montc lair Basin provi d e a conveyance capacity of approximate!_ 39% of the 100 -year event when flowing at 100 % capac i ty. lbis means that the exjsting Montclair Basin stonn drain system has the abilit y to convey stoml\vater runoff resul ting from a sto rm l arg e r t h a n th e 2-year event b ut less than the 5 yea r even t. In addition n u m ero u s areas the Montclair Basin do not contain a stom1 drain pipe network. These areas curre ntl y rel y o n t11e streets t o convey stonnwater nmoffto the nearest inlet and pipe syste m Section 7.3 of t h e D e n ver Storm Draina ge Design and Tec:hnic.:al C rit eria Manual states that local and collector streets cru1 convey stonnwatc r w ithout curb overtopping during t h e minor-eve n t Areas wer e identified within the Mon tc l ai r B asin that l ikely excee d s th e al lowabl e min o r -eve nt stree t capacity Approx im ately 2 490 acres of lan d w i t hin th e Montclair Bas in arc est im a t e d t o excee d the al lowabl e stree t conveyance capac i ty durin g th e min o revent a n d require storm drain syst c tns. N um e rous s ump areas exist w ithin the b as in and seve r a l flooding in cide n ts h ave been d ocw n ente d b y th e City a nd Coun ty of D e n ve r. Most notabl y, the Coca Cola b ott lin g p l a nt l ocate d near t h e i ntersection ofN. Rac e Street ru1d 381h Ave n ue has r epo rted freque n t flooding at tl1eir faci lity. A l so. freque nt street flooding is r eported on N Colora d o Boulevard and E. 23rd Avenue. N Colorado Boulevard and E. 17th Avenue E. Bata v ia Place and N. Clennont Street all i n B asi n 4500-01 ln B asin 4500-03 flooding has been reported along E Colfa x Avenue atN. Elm Street and between N. Glencoe Street and N I vy Street. in the sump area along E 14th Aven u e between N. J asmine Street and N Kearney Street. the 1100 b lock ofN. Locust Street, t h e I I 00 b l ock ofN. Ley d e n Street. tl1e 900 block ofN. Magn ol i a Street. a nd at E 9th Aven u e and N. Niagara Stre e t. I n Basin 4500-04, tl1ere have been reports o f stonnwater surging out of manholes along E H ale Parkwa_. and re p etitive flooding in t h e sump area along E Se vern P l ace between N Jer sey Street and N Jasmin e Street. Proposed Capit a l Improvements : The m ajority of the proposed sys tem i mpro veme nt s con sist of approximate l y 19 acr e-feet o f detention storage in the City Park socce r fields and approxjmately 193.83 1 feet (36.7 mil es ) of sto rm drain pip es/box c ulverts September 2 0 J..J Project A: E. 33rd Avenue Svstem The 33nt Aven u e project is located just north of City P ark and includes land tributary to Martin Lutlter K i n g Drive and 33rd S treet. Primary upgra des wit hin the project basin include a replacement t runk line a long 33rd Avenue that beg in s at Williams Street and ext e nd s u p t h e basin along Martin Luther King D rive. 3l' t Aven ue, and Monroe Street. T he proposed tmn k l ine l ocated along 23'd Ave nue in t h e City Par k P roject intercepts peak flows f ro m subbasins 430 and 440 and conveys t h e flow to the City P ark Soccer Fi eld detention storage fac ili ty. This di versio n e liminates the need to replace a portion of th e exi sting tru nk line system t h at extends in a southeasterly direction from 29th and Monroe Street to 23rd Avenue and Dahli a Street. P rojec t B : 38th Street Svstem The 381h Stre e t pro ject i s t h e s m al lest of the Montclair B asi n projec t s w ith o nl y a pproxim ate l y 54 acres of contributin g land Th e project i s l ocated at tl1e South Platte River j u s t wes t of th e collectio n syste m basin o u tfall and is h yd rologically di scoru 1 cc t e d f r o m t h e rest of th e M o ntclair Basin Prop osed improve m ents i nclud e a trun k line locat e d alo n g 38111 Stre e t a nd two s m a ll l ate ral s to serv ice comm e rcial areas P rojec t C : 401h Avenue System The 40th A venue project i s locat e d at the down stream end oftb e project b asin The upstream p o rtion of th e projec t begin s n ear t h e int e r sectio n o f 38th Aven u e a n d Hrurison Street and ext ends downstream t o t h e s tomt drain trunk l in e l ocated a t the int ersect i o n of High Street a nd 40th A venue. The maj o r upgrad e w ithin t h e project is a proposed 8-foot x 8-foot R C B C t o repl ace d1c existin g 69-iu c h stonn d rain l ocated along 40111 Avenue w hi c h is curr e ntl y under construction as part of the RTD F asTracks East Corridor project u p toN. Columbine Street. Project D : Citv P a r k Svstem Th is project con tains C it y P ark ru1d r eside ntial areas l ocated just east ofth e park. The proposed capi t al i m provement modifies C it y P ark to pro v i d e adru ti onal detentio n storage v o l um e. Storage i s to be provided i n two l ocatio n s w ithin the P ark : C it\ Parks F erri! Lake w hi c h was modified in 2007 / 2008 to inclu d e det e nti on. and proposed sto rage ball fields locat e d near tl1e northeast comer of the Par k. The r educt ion in peak flows resulting from t he detention s t orage e liminate s the need to up grade the cxjsting D enve r Zoo tru n k lin e The project also inc ludes a p r o p osed trunk line locat e d along 23'd Avenue to inte rcept p eak flow s from subbas in s 430 and 440 located in tl1e 33rd Av e nu e P roject. Project E: High Street S ys t e m The H i g h Street Project contains the existing major outfall syst e m for the Montclair B asin l oca ted a long H i gh Street. l11e pri mary u p g r a d e w ithin t h e project i s a prop ose d 1 2-foot x 8 -foo t RCBC o utfall t o tl1e South Pla:tt e Rive r aligned alon g the north s id e of the P epsi Bottlin g Plant. The m ain tnmk lin e wou ld tJ1en ext e n d u p stream along 40th Street t o a c ro ssing unde r th e U ni o n Pacific Railroad ya rd The t nmk lin e \.VOuld contin u e east in 40th Av enue t o Wi lli a m s St r ee t w h e r e it wou l d h ead south paral l e l t o tl1e exi s tin g trunk lin e located in Hi g h S t reet. A paral l el !in c was selec t e d over direct r e plac e m e nt for thi s a lt ernative becau se of th e redu ce d peak flows resultin g from t h e d ete ntion storage in City P ark. TI1e outfall p o rti o n up t o 40th Ave nu e and Williams St ree t is currently under cons t r u ctio n in conjunction with the U DFCD and the RTD Fastracks project P rojec t F : J ackson Street Svst e m The J ackson Street project has seen recent construction of one block of stonn drain in J ackson Street from E 17th Avenue to E Colfax Aven u e. to serve as the o ut'1.11 for Project 4500-04 A Future portwns of th e project include a new drain in Madiso n from 17th Aven u e to L6tb A ve n ue as well as t he upper portion of a new dra in in E 14th Ave nu e fro m Cla yton to St. P aul. w hich ,,ilJ contin ue in E 14th Aven u e toN. Gariield Street as shown in B asin 4500-0 4 P rojec t G : 26th Avenue Svstem The 26th Avenu e P roject i s l ocated just at the north botmdary of City P ark and mcluded land tnbutary to Gavlord Street and 26th Avenu e. The major improvement is d1e proposed new R C P in 26t h Avenue and d1e in Mil waukee St reet. Clayton Street and 28th Avenue P rojec t H: E 191h Aven u e Svstcm TI1e E 19th Avenue syste m collects nmoff in B 1 91h A venu e fro m J as min e Street con veyin g i t to E 16111 Avenu e and Cherry S t r ee t t o co nnect with Pr oject 4500-03-A. 1 61b Avenue System Page 114

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Key Map !. .. ( 0062-01 ) a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. 0 700 1,400 For Detai l ed Hydrology See Tec h n i cal Append i x and Wor k Map .-. Collection System ...... Boundary 1-1 Topographic Basin Proposed Storm Pipe UDFCD Study Recommendations -( 4500-02 ) Legend Existing Storm Pipe ( 0060-01 ) Proposed Projects ..,.. A-E 33RD AVENUE SYSTEM: $20,293,939 .... B 38TH STREET SYSTEM: $2,639,338 C40TH AVENUE SYSTEM: $14,881,148 ..,.. D CITY PARK SYSTEM: $9,601,961 ._ E HIGH STREET SYSTEM: $9,691,541 F JACKSON STREET SYSTEM : $2,240,279 _,.. G 26TH AVENUE SYSTEM: $3,421,433 ..,.. H-E 19TH AVENUE SYSTEM: $4,320,783 ... --. Proposed Detention -+Existing Transit Line Basin 4 50 0-0 1 -.J Basin Existing Basin g City and County Boundary city park 11 Potential Inundation : Other Municipalities Feet Proposed Pipe L__J Area _____________________________ __________ ___ s ig n ir ic a _nt_ F Ioo __ d in g L oc a tio n ________ P Ia n n e d T ra n _sit_ L in e __ ____________________ "' Boundary Designed Storm Improvement -Existing Surface Flow Pag e 115

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D e nver Stonn Drain age Master Plan Basin 4500-03 (Park Hill Colfax) Existing Syst .em Description: Collection System Basins 4500-03 and 4500-04 (Upper Montclair) have their own stormwa ter conveyance systems that eventually drain to City Park in Basin 4500-0 I H owever, tbe upper reaches ofthese two basins share tributary area where the existing pipe network conve ys water into Basin 4500-04 along H ale Parhvay. but surface flows travel north into Basi n 4500-03 from th e sump area in E Sevem Place between J ersey Stre e t a nd J as min e Street, where a split b etwee n surface flows a nd pipe conveyan ce occurs Proposed Capital Improvement s: Project A : 1 6'h A venue Svstem Th e 16'h Avenue project is l ocated in the southeast port i o n of the Montclair Basin a nd collects sto mn. vater runoff in a tnmk lin e that nms along 16th Aven u e and ends at Harrison Street n ear th e so utheast comer of City Park. TI1is project contains approximatel y 1 9 4 acres of primaril y reside ntial land but includes commercia l l ands l ocated along Colfax Boulevard Subbasins within the includ e 280-290. TI1e primary upgrade within the project is a replacement tnmk Jine l ocated along 16th Avenue and extencling up through the : project, and one l ateral lin e Project B: Glenco e Stre e t Svstem The Glencoe Street project tnmk line starts at the upstream e nd of the 16th A venue project and zigzags along Glencoe Street. Colfa-x Avenue J ersey Street 14th Ave nu e. Kearney Street 1 31h Avenue. L eyden Street 11111 A venue and ends at t h e intersection of 11th Avenue and Monaco Street Parkway An additiona l spur trunk l ine is proposed betw'een lOth Avenue and Sevem Place. This w ill miti gate repetitive flooding at E 14th Avenue a nd N J as min e Street, alon g E. 14th Avenue and the II 00 blocks ofN. Locust Street and N Leyden Street. Approximatel y 350 acres of land contrib utes stonmvater nmoffwithin th e proj ect including subbasins 260 270 and a portion of250. The majorityofland w ithin the project bounds is residential but includes comme rcial lands l ocated along Col fax A venue. The primary upgrade within the project i s a replacement of trunk lin e anew conveyance serving the Severn Place sump and two lat e ralli.nes Project C : Monaco Street System The Monaco Street proje'Ct has a tnmk line starting at th e intersection of M on aco Street and l l lh A venue and z igzags alon g Monaco Street I oth Avenue Magnolia Street. 9th A ve nue Niagara Street to end at the intersection ofNiagara Street and 6th Avenue Parkway. There are three laterals in 6th Avenue 8th Avenue and lOth Avenue. This project wi ll mitigate flooding a t 93 0 N Monaco Street Parkwa y flow depth exceeding street-dep th crite ria at 799 N Niagara Street and other l ocatio n s in the upper portion of th e collectio n syste m basin. A 66-incb RCP spur line, going east in E. 8th A venue will serve t h e s um p area in E. Severn Place, between N. Jerse y Street and N. Jasmine Street to account for the flo w split occurring in the 2-year and 5year event. ide nt ified in this Master Plan update Approximatel y 4 3 2 acres of land contributes stom1water runoff within the project inclucling subbasins 230, 240 and a portion of 250. Additional surface flow enters the project from Basin 4500-04 a long Niagara St reet, at the upper e n d of t h e basin A 1 00-year outflow from t h e s ump at E. 51h Aven ue and N Newpot t Street was con structed in 2013 The maj ority of land w ithin the bOlmds i s residential. The primary upgrade w ithin this project is a rep]acc ment of the exist in g tnmk line September 201-/. Page ll6

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e 5 a; I v 0 !Z g g. l c. i e 1l 0 .!!! ;:: K ey Map [ 4600-02 ) NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. 600 1,200 Feet 1 inch equals 1 200 feet For D eta il ed Hydrology See T ec hni cal Appendix and Work Map 0 Cl) 0 0 <( 0 -' 0 u 2 .... Collection System ...... Boundary 1-1 Topographic Basin Boundary Thalweg [ 4500 -0 4 ) Proposed Storm Pipe --UDFCD Study Recommendations X Proposed Pipe Disconnect -L egend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location r Proposed Detention Basin Existing Basin 11 Potential Inundation L__J Area -+--Planned Transit Line [ 4400-02 ) -+-Existing Transit Line D City and County Boundary ...... : Other Municipalities D Other Counties Creamt Pari< [ 4401-02 ) [ 4401-03 ) 4 I \ I / I .......... : I I : I ""-Proposed Projec t s .,.. A16TH AVENUE SYSTEM: $12,782,213 BGLENCOE STREET SYSTEM: $16,437,403 .,.. C MONACO STREET SYSTEM: $14,143,800 Basin 4500-03 Park Hill Colfax Denver Storm Drainage Master Plan P age 117

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D enve r Stonn Drainag e Master Plan Basin 4500-04 (Park Hill -6th A venue) Existing Syst em Description: Collection Systems Ba si ns 4500-04 and 4500-03 ( Upper Montclair) have t heir own stor m wate r conveyance systems that eve ntually drain to City Pa rk in Basin 4 500-0 I Ho wever the upper reaches of these t wo basin s share tributary area where the existing pipe network conveys water into Basin 4500-04 along H ale Park way. but surface tl ows travel north int o Bas in 4500-03 from th e sw11p area in E. Sevem Plac e b etween Jersey Street and Jasmin e Street < w h e r e a split b etwee n surface tlo ws and pipe conveyance occurs Proposed Capital Improvements: Proj ect A: Jack son St. Svstem This project starts at E. Colfax Avenue aodN. J ackson Street connecting to a stom1 drain constructed inN, Jackson Street from E 17tb Avenue to E. Colfa-x Avenue in 201 2 [t turns west in Colfax Avenue to Garfield Street. The system exte nd s up Garfield Street to E. 12th Avenue y v h e r e it turns east in 12th Avenue actoss Colorado BDltlevard toN. Albion Street. It sen,cs as the outlet for Proje cts B F and G. Project B : Hal e P arkwav Svstem Hal e Park way l i es in a hi storic draina ge swale and is to significant surface tlows and stom1 drain s urcharging The Hal e Parkway Proj ec t is l oca ted in Hal e Park way b etween N Albion Street and 8th Avenue wit h approximately 264 acres of contributi n g area The project contains commercial lands in the r eaches along Hal e Park way t o E. gth A ven u e, with the remainder being re s id e ntial areas. Subbasins 150 -170 and part of 140 are included wi thin th e projccL The project includes an extensive network of prop dsed pipe systems, includin g an 8-foot x 11-foot (96-inch x 1 32inch) b ox cul vert trunk lin e that begins at E. 1 211' A venue and Colorado Boul eva rd and exte nds upstream along H a l e Parkway Project C: 81h Avenue Svstem The gth Avenue project is l oca ted in the eas t ern portion of Bas in 4500-04 a nd collects stormwater runoff in a trunk line that zigzags along gtn Avenue J e rsey Street, Severn Plac e JasnJ.ine Street 6th Avenue Krameria Street and 4th Avenue. Th e project contains approx im ately 30 I acres of primari l y r eside ntial l and including subbasins 90-110 Th e primary u pgrade within this project is a replacement tnmk lin e and several lat erals attd w ill service the smnp area in E. Severn Pla ce b etween Jersey Street and Jasmine Street i n conjunction wit h project 4500-03-C. TI1is project would mitigat e stonn surchar g ing of manholes at E. 81h Avetme and N. HoJiy Street, and repetitive flooding in the s ump in E. SevernA venue b etween N.lvauhoe Street a nd N. Jasmin e Street. An ad ditional 66-inc h RCP wo uld also drain the sump area in a 5-year storm event, to Basin 4500-03 t o accatmt for t h e basin s plit flow that has been id e ntified in this Master Plan update. Project 0 : Kran1eria Street Svstem This project is locat ed at th e south portion of the Basin 4500-04 and is primarily r eside ntia l area and park a rea. The project contains approximately 773 acres of contributing a r ea including subbasins 10-80 The primary upgrade is the replacement oftnmk line that runs along Krameria Street an d Kearney Street and several lat era l s. Project E: G r ape Street Svstem This project is locat e d at the central portion of the Basin 4500-04 and is primarily residential. The proj ec t includes approximately 345 acres of contributing area including su bbasins 120 130 and a portion of 140 The primary upg rade i s th e r e plac e m e nt of trunk lin e that nms along G r ape Street Hudson Street and Holl y Street between glh Avenue and E. Cedar Avenue and severa l Laterals September 20 1-t Proj ect F : Jackson Street Svstem Lateral s This project is locat e d at the most north portion ofthe Basin 4500-04 and is primaril y residential area and commercial districts locat e d along Colorado Boul evard. The primary improvement is to upgrad e the exis ting later a l s w hich are locat ed in Colfux Avenue and 12th Avenue and proposed new laterals to be constnictcd in 14tb Avenue and 111b Avenue. The proposed lateral in E. 14th Avenue go ing west from N Garfield Street continues wes t to N. Clayton Street as shmvn in Basin 4500-0 I. Project G: Colorado Boul evard Svstem The Colorado Boulevard project is located in the n orthwest portion of the Basin 4500-04 and collec t s stonnwater mnoffin a tnmk lin e that runs alo n g Colorado B ouleva rd The tributary area is approximately 362 acres including subbasins l80, 190, 200 Th e land use in this project bounds i s primarily r es id e ntial area with commercial dist1ict s are located along Colorado B o ul evard. Primary improvement wi thin t hi s prq}ect includes a replacement of the tnmk lin e in Colorado Boul evard and several new lat era l s. Page 118

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K ey Map ( 4 500 0 1 ) a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. 0 650 1,300 Fo r D eta il e d Hydrology See T ec hni cal A pp en dix and Wor k M ap ( 4 600 02 ) .-. Collection System ...... Boundary 1-1 Topographic Basin "' Boundary ( 4500 0 3 ] Proposed Storm Pipe UDFCD Study Recommendations -L egend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow r' Proposed Detention -.J Basin Existing Basin -+-Existing Transit Line D City and County Boundary .. ... 11 Potential Inundation : Other Municipalities ( 4 60 0 -03 ) [ 4 4 0 1 03 1 Weste1fY' Creek Dam Pond ( 44 0 1 -0 4 1 .,.. A JACKSON STREET SYSTEM: $8,193,484 ... B HALE PARKWAY SYSTEM : $14,122,302 .,.. C 8TH AVENUE SYSTEM: $12,853 692 ... D KRAMERIA STREET SYSTEM: $14,272,190 ... E -GRAPE STREET SYSTEM : $10,365,868 F JACKSON STREET SYSTEM LATERALS: $9,090,880 .,.. GCOLORADO BOULEVARD SYSTEM: $12,672,779 Basin 4500-04 Pa r k Hill 6th Avenue Feet Proposed Pipe L__J Area _____________________________ __________ ___ s ig n ir ic a nt F Ioo __ d in g L oc a tio n ________ P _ra_ n n e d T ra n _sit_ L in e __ ____________________ P age 1 19

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D e nver Stonn Drainage Master Plan Basin 0062-01 / 4500-02 (36th & Downing) Exi sting System Description: These two collection system basins combi n e d include a mi x of industrial. commercial and residential land uses and include 2.856 tributary acres (4.46 square mi l es) The basin i s fuJiy built-out with older neighborhood resi dential in the upper reaches and commercial in th e lower r e ach es Tili s basin includes Lower D owntown. Coors Field. rail yards and a n mnbe r of existi n g reside nti a l neighborhoods. I t is characterized b\' t e rra ce topography in the upper portion s of the basin and ve r y flat outfalls near th e South Pl atte River Ti1is condition results in inadvertent detention near t h e basin headwat e rs and surcharge of stonn drains i n 1 0\ver reach es. Curr e ntl y most of th e d rainage ( nearJy 75 % ofthe b asin) outfal l s through o n e 8 J -inch storm pipe at 36th Str eet. w ith a pproxim ate l y 1 ,936 acres t ributar y t o tl1is o n e outfa ll. The exi s tin g pipe has approx im ate l y 476 cfs capacity. b u t the h ydrology indicates the flow wi ll be over 1 .000 cfs in a 2-ycar eve nt. and 1,700 cfs in a 5-ycar event (des i gn flow) There are oppo rt unities for rcgioL1aJ water q uality treat ment off th e existing 8 1 inch p ipe ncar th e Sout h Platte o u tfal l s in ce it curre ntl y can convey a rainfall (WQCV) over such a large deve l oped basiJ1 a r ea. Drainage Defici e ncie s: The ex i sti n g drainage system has l ess than a !-year capacity R ainfall nmoff in excess of t h e stom1 drain capaci t y has a h istor y ofponding in the sump and flat areas M an of the existing stonn drains surcharge out the manholes during l arge storm events. Major drainage problems have been exp erie nced in this basin. partic u larl y north of Coors Fi e l d D uring a major storm even t split flow conditions exist in the basin. whereby stom1 runoff is exported and imported out and into tl1is basin For split flo w condition see the 3 1 s t Street & 36'1 Street Outfall Study and Com:ep t Design R eport, December 20 1 2 b y Wi I son and Company. Potential Inunda t io n Areas: Severa l areas of p ote n tia l immdati o n have been ide ntifi ed w ithin the bas in m os tl y in areas w h e r e the stree t s becom e very flat. The areas surrou nding the int e r sectio n s o f 36th Street/B l ake S t reet. 31 $ I Street / Bl ake Street 32ncl Street l7'h Avenue /Lafaye tte Stree t 16th Ave n ue/F r a nklin Street and 16tn A ve nue/Cl arkson St reet have been identified as l ocations where 1 00-year inundat i o n depths couJd reach up to 3-feet in dept h durin g a I 00-year event. Propo se d Capita l Improvements: Thi s basin requi res improve m ents prinlarily to the outfall since the lateral n etwork i s curre n tly extensive in t h is basin The outfall shoul d have 5-year capac i ty. whereas the lateral n etwork through th e r esidential areas shoul d have a 2-year capacit y The exis tin g 81-inc h outfal l in 361h Street is unders i zed and additional o utfall s are needed to re l ieve the burden on th e existing pipe Constructing two new outfalls in this basin will reduce the tribu t ary area of the existing outfall. l11e 31$1 Street & 3rJ" Street Outfall Study and Co ncept D esig n R eport, compl eted b y Wilson and Company in investigated severa l o utfall alternatives w ithin the basin and the reconun en d a tion s from t h at report are reflected in this Master Plan Thirteen major drai n age project s arc proposed for this bas in as described b elow : Sept embe r 2 0 I-I Project A: Marion Street Svstcm Phase I con ne cts to the recently designed River North O utfall l ocated in Street. The Phas e l exte n sio n includes a new I 02-inc h pipe in Marion Street from 32nd A venue t o 29'h Avenue. The existing pipe \Vill be cut and plugged to provide additional capac i ty in the downstrean1 syste m where the new pipe crosses the existing s t orm pip e Work o n thi s project should begin at the outfall and exte nd upward to improve the leve l of drainage service in the bas in Project B: Marion Street System Phase 2 stonn drain' ill contin u e up the basin wid1 a l 02-incb to 90-tnch pipe in D owning Street to 2 1 s t A ve nu e. Project C: East 24th Avenue Svstem provides additional stonnwate r collectio n for the propo se d trunk line in P roject B I t includes a 60-inch pip e in 24th Avenue w ith addit ional lines exte ndin g up to 201h Ave nu e and Vine Street. lhis prqject a lso Incl udes replac in g exis t i n g s m al l pipes with 1 8-i n e h diameter pipes to meet curre nt drainage criteria. improve collection/conveyance and r e du ce maintenance problems Project D : Citv P ark West Dra in age Improve m ents ext e nd s into the upper b asin with an84-ineh to 36 inc h diam eter pi pe "n1is p r oject a lso includes r e p lacing exi s ting s m all pipes w ith 1 8in c h diam ete r pipes to meet curre n t drainage cri t eria. i mp rove collec tion /conveya nce and redu ce maintenance problem s Project E: East I th Ave I mpro ve m ents include replacing existing s mall pipes with 18-in ch diameter pipes t o meet current drainage criteria improve col l ection/conveyance and reduce maintenance problems. Project F : 27lh Street interceptor-Ph ase l includes maximizing t he use of the existing I 08-i n c h pip e i n the Coors Fi eld Parkin g Lot. Curren t ly. t h e trib u tary area t o the pipe is o nl 88 acres. The outfall ,.,jll extend u p 27tb St reet to Champa Street wid1 a 96-ineh pipe P roject G : 27th Stree t Interceptor P hase 2 will continu e upstream in 27th Street from Champa Street to Washington Street and along Washin!:,rton Street to 19'h Avenue wi th a 90-inc h to a 72 inch pipe P roject H: 27th Street I nterceptor Ph ase 3 will c tend along Clarkson Street from 19th Avenue to 141h Avenue witl1 a 60-inch pipe t r ansitioning do' n t o smaller p ip e up into the basi n This project also includes lateral s in 16th Avenu e. P roiec t 1 : 2711' Street ln t e r cepto r W a lnu t/Market L ateral Includes a new up sized pip e n etwo r k in Walnut / Market Street south of 27th Street. P ro j ec t J : 2 7th Street Int e rceptorC hampa Lat e ral consi sts of a new box and pipe network in Champa Street sout h of 2 71 h Street Project K: North Mari o n Street Lat erals proposes to replace the existi n g small stom1 drains east of Project A \\ ith 18-inch or larger pipes to meet current drainage cri teria and reduce maintenance Project L: East 33rd Avenue L aterals includes a s y stem to balance out the re m ainder of the basin tributary t o t b e existing outfall. A new 42-incb pipe at 33'd and Downing Street will disconnect the existing p ipe in H umboldt Street and con ve y ru noff to t h e existi n g 81-i nch pipe in Downing Street. whic h is b e in g relived w ith constructio n of th e new o u t fall in 33rd Street. I n addition existing sm all stonn dra i n s are proposed to be replaced w ith 18-incb pipes to meet current drainage criteria and reduce maintenance P roject M : Grant Street Storm Drain collects runoff from the existing stonn drains in 9th and lOth Avenues at Ogd e n Street and delivers runoff in a 5-year eve n t to the 13t h A venue Extension project in B asin 4600-0 J l11is prqject also includ es upsizing tl1e exis tin g s torm d r ain in Grant Street from I Oth to 13th Ave nu e Page 120

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0 K ey Map [ 0061 -02 ] [ 0061 -01] 800 1,600 For D eta il e d Hydrology See T ec hni cal A p pend i x and Wor k M ap ..... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe ... UDFCD Study Recommendations [ 45000 1 ) L egend Existing Storm Pipe Designed Storm Improvement --Existing Surface Flow Significant Flooding Location (' Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__.1 Area Planned Transit Line Existing Transit Line D City and County Boundary ( 450 0-04) [ 4600-02 ) Pr o posed Pr o j ec t s NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems. not proposed drainage improvements .... A MARION STREET SYSTEM PHASE 1 : $3,336,352 ...,. B MARION STREET SYSTEM PHASE 2:$8,878,818 .... D CITY PARK WEST DRAINAGE IMPOVEMENTS : $14.235,873 ..... E E 12TH AVE IMPROVEMENTS: $3,783.762 ..,. F27TH ST INTERCEPTOR PHASE 1 : $8,086,632 ..... G 27TH ST INTERCEPTOR PHASE 2:$7,924,292 .... H TH ST INTERCEPTOR PHASE 3: $4,452,452 .... 127TH ST INTERCEPTOR WALNUT/MARKET LATERAL: $1,988.101 ...,. J 27TH ST INTERCEPTORCHAMPA LATERAL: $4,477,254 ...,. K N MARION ST LATERALS : $2,422,884 .... LE 33RD AVE LATERALS :$10,260,820 ..,. MGRANT ST STORM DRAIN : $7,652,395 Basin 0062-01 & 4500-02 Lower Platte Valley and 36th & Downing

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D e n ve r Stonn Drain age M as t e r P l an Ba s in 4600-01 (Ce ntral Bu s ine ss Di s tr i c t) Ex i s ting System Descr i p ti on: Thi s collec tion sys t e m ba sin c onsist s of 1.4 27 acre s ( 2 23 s quare mil es) a nd is f ull y built-o u t w ithin t h e C e n t ral B us in ess Dis tri ct. TI1e b asin from 6111 A ve nu e t o th e col1flue n ce w ith S ou th Platte Rive r a l ong t h e C h erry C reek corri d o r. Blue print Denver s h ows the do w n t o w n area Subjec t t o Change Onl y th e s m a ll r es id e nti a l n e i g hb o r h o o ds so u t h of C ol f ax and west o f C h e rr y C r eek a r e s h ow n as b ei n g A reas of St abi l i ty" A ll f01mal dmin age fa c iliti es from thi s b as in o utfall into Ch e r ry C r ee k but surface fl ows fro m the d own t o w n a r ea drain to the S o uth Platte R ive r int e r ce pt e d s t ormw ater i s di sc harged in at l east 4 2 sep ara t e s t o rm dr a in age outfalls int o C h erry C r ee k So m e o f the mor e m a j o r outfalls includ e : l 6 x 4 box c u lve rt fr o m the P e p s i C enter lO'x 5 box c u lve rt co n stmcte d f o r th e Co nvent io n C e nt e r up to 1 4d' & St o ut a nd e>.1end e d as 84 -inc h pip e in Stout a l m os t t o 1 61h St reet 96-in c h p ipe ou tfa llin g at 14th & Market Street dmiuiu g l a rge pipe in Larimer Street 5 4-in c h p ipe f rom D elgany Street 8'xs box culve rt o utfall cons tru c t e d in 14'h Ave nu e up t o 13th Ave nue an d D el a ware Stree t The s torm drain infra s tm e tur e co n s i s t s o f a network of se p ara t e out falls and l ate ral s i n mo st st r ee t s. A g rid p a tt e rn o f l a teml s exists i n th e d ow nto wn area. As stree t impro ve m e n t s are co u st m c t e d i nl e t s h ave b ee n imp r ove d t o c urr e nt s t a nda r d d es ign s. D ra i nage fro m dow ntown i s co n str ain ed b y t he elevat i o n of t h e Ch e rr y Cree k floo d p lain e l evation w hi c h ge n e rall y red u ces ca p ac ity and c reat es s ump or surcharge condi tions durin g m a j o r s t orm eve nt s Drai nage D efic i enc i e s : ln ge n era L th e exi s tin g d rain age sys t e m h as capac ity t o co n ve y th e 2 to 5 t o even th e 1 0 0year stom1 evet1t t o Cherry C r eek R e d eve l o pm e nt and c urr e n t drainage cri teri a h ave requir e d the co n structio n of 1 0 0yea r c ap aci t y outfalls o r a t th e l east to c onstru c t th e l a r ges t sto nn pi p e po ss ib le T wo maj o r -eve nt FL0-2 0 a n a l y ses Colfax C orrid o r and Down tow n a r ea, we r e p erforme d thro u g h thi s b asin a nd ide ntifi e d t h e P o t entia l lmmd a tion Ar ea fo r th e Mas te r Pl a n Update Proposed Capital Improvements: Th i s b asin r equir es impr ove m e nt s p rim arily b y i ncreas i n g the capaci t y o f th e outfa li s a nd lat e r a l n e twork. Outfalls thr o u g h th e c omm e r c i a l rueas ( a nd especi al l y t h e Ce ntr a l Bus i n ess Distric t ) s houl d h a ve a min i mum 5-year cap a ci ty Few opp o rtun i t ies exist for d e t e nti o n i n thi s de n se l y d eve l o p e d bas in Th ere f or e. impr ove m e nt s have gen e rall y inclu de d up s i z i n g conveyance fac iliti es Prop osed pr ojec t s incl ud e : Project A: S tou t Street Outfall A new I 0-foot x 5 foo t b ox cu lvert vvas instal l e d as p a rt o f r e d eve lopm e nt of th e Conve nti o u Ce nter in th e mid-2000 s t o c reat e an C;\.')Jand e d ou tfal l t o Ch erry C reek S t o u t S t r ee t Ph ase ll e:-...1cnd e d t h e s t o rm dtait 1 t o near 16th S t ree t Futur e e>..1en s i o n s a re-n ee d ed t o int e r ce pt m noffi n t h e up per b asi n a r eas an d u t ilize t he cap acity of th e new box culve rt o u tfall. P ro j ec t B : C b e n v Creek Outfall s E x i s tin g o utfalls h ave 1 -2 year capac i ty and s hould be Ups i ze d t o 5 year capaci ty b y c rit eri a ln a ddi t i o n all 1 2 and 1 5 i n c h pipes s h ould b e repla ce d with 1 8in c h pipes September 20 1-f Proj ec t C 7 W es t 1 4th A ve nu e E:-...1 c n s i o n A pro p ose d 3 6-in c h s t o rm drain in 14th Aven u e n o rt h of D e la ware Stree t w ill improve t he c ap ac i ty o f th e ex i s tin g 24 -in c h p i p e Project D : W es t 81h A ve n ue Outfall The ol.ltfall s in 8tb A ve nu e n o rth o f Ch ctry Cro c k s h o uld b e up size d fr o m an d exis tin g 2 4-in c h pip e to a 48inc h pip e t o pr ov id e 5 year p r o t ec tion P ro j ec t E : W es t 9th Ave nu e Ou tfall TI1e ex i s t i n g outfall in 9th A ve nu e n o rth of CheJTy Cr ee k s h o uJd be ups i ze d from a n o ns tandard 26-in c h v itrifi e d c l ay pi p e t o a 36 -in c h pipe to pro vide 5-year protecti o n Pr o i ec t F : W est C olfax A ve nu e O utfall A new 84 -in c h o utfall in Colfax n o rth of Ch erry C r eek will r e p lace t h e existi n g 38in c h outfall and pro vide 5-ye a r c apacit y. Pro jec t G : Cmti s Street Outfal l B as i n s 60 a nd 65 c urr e ntl y drain 1 1 9 acres via an ex isting 39-in c h pipe. U ps i z i n g this outta11 to a 60-in c h p i p e would pro v id e 5 year s to1m cap ac i ty Al t e rna tive l y d ete n tio n in Lin co ln P a rk was co n side r e d to a void u p s i zing the o utfall H oweve r cu rr ent l an d u se in t h e par k exist in g trees and t h e rid ge top og m p b y in t h e p ark have prompt e d th e co n s i d e rati o n of co n vey ance ove r d e t e ntio n P r o j ec t H : N Ban nock S t I mpro ve m e n t E xisting 1 2 a11d 1 5-inc h pip es a r e p r o p ose d t o be replaced w it h 1 8 inc h pip es t o me e t i n g curre nt drai n age c ri te ri a and r e du ce main te n ance Proj ec t I : N S p ee r Bl v d I m p r ove m ent E xisting stom1 d r ai n s are pro pose d t o b e r e p lace d w ith Iar gcrpi p es and 1 2 a n d 1 5 -iu c h pipes a r e pro p ose d t o b e rep l ace d with 1 8-inc h pip es t o m ee t c urr e nt d rai n age c rit eri a a nd re du ce main te nan ce P ro ject l W es t 13th Ave nu e Ex t e n sio n Th is i s th e up s tream porti o n o f 14th A ve nu e Outfall Pr o j ect Thi s sto nn drain w ill cap ture nm off fr o m 283.3 acres that wer e p rev i ous l y tri butruy to th e sto rm p i p e in Gran t Stree t th a t i n th e p ast ha s o u tfal lcd t o the S o uth Platte Ri ver at 36th S t r eet an d co n vey it t o Ch e n y Creek in s t ead A p r o p ose d 60-in c h pip e e a s t of B roa d way. t ran s iti onin g to a 72 i n c h wes t o f Broadw a y w ill r eplace th e ex j s tin g 2 4-i n c h s t orm drain an d pro vide 5 year cap acity Thi s p roject int e r ce pt s th e existing storm dr ai n in G rant Stree t at E 13th Ave nu e prov idin g r elie f t o th e do w n stream sys t e m in Gra nt St r eet. Proj ec t L: W est l lu, A ve nu e Imp rove m en t s The exi s tin g o utfall a t the int e r sec tion of l l th Aven u e and Sp ee r Boul ev ard i s c apable of co n vey in g stonn n m off up to 5 year eve nt : h owever. the exi s tiu g p i p es i n t he 11'11 A ve n u e eas t of Sp ee r B o u l eva rd a r e und e r s i ze d and n ee d e d t o b e r e pl ace d with R C P ranging in s i ze fro m 24 -in c h di a m e t e r to 4 8-inc h diameter. P age 1 22

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K ey M ap 0 600 1,200 For D e tail e d H yd r o log y See T ec hni cal App e ndix and Wor k M a p N BROADWAY ...... Collection System ...... Boundary 1-1 Topographic Basin .. Boundary UJ :r: 1-0 N w UJ :r: 1-"' UJ South Platte River Proposed Storm Pipe .... UDFCD Study Recommendations L egend -Exi sting Storm Pipe Designed Storm Improvement --E x isting Surface Flow Significant Flooding Location ---...... N LOGAN S T \ N G RANT SJ t!; w w :r: 1-M [ 006301 ) (' Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__J Area Planned Transit Line Existing Transit Line D City and County Boundary NOTE: Trans basin flows shown with a heavy black arrow are based on e x isting storm drain s y stems, not prop o sed drainage improvements. N BANNOCK S T [ 0063-01 ) [ 0 0 6 4 -02 ) A STOUT ST OUTFALL: $9,039,627 B CHERRY CREEK OUTFALLS: $15,353,598 C W 14TH AVE EXTENSION: $1,745,052 D W 8TH AVE OUTFALL : $1, 959 002 E W 9TH AVE OUTFALL: $3,260,924 F WEST COLFAX A V E OUTFALL: $ 9,924,684 H N BANNOCK ST IMPROVEMENTS : $2,604,617 I N SPEER BLVD IMPROVEMENTS : $642,604 J W 13TH AVE EXTENSION : $4,190 245 L W 11TH AVE IMPROVEMENTS: $2, 454,683 Basin 4600-01 Central Business District

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D e n ver Stonn Drain age Mast e r Plan Basin 4600-02 (Cherry Creek Mall) Existing Syst .em Description: This c o llection system basin consists of2.928 acres (4. 5 7 square mile s) and is fully 1l1 e basin e"A'te nd s from Colorado Boulevard to 6111 Av e nue along the Cheny C ree k corridor and includes th e Denver C o untr y Clu b and t he Cherr y Creek M all in the c ente r of the ba sin. Blueprint Denver s h ows the area bound e d by Colora do BouJevard 6th A venue, York Street and Cheny Creek as a n A r e a of Chang e. The r e m a ind e r (ove r two-thirds of th e basin) i s s hown as b e ing a n ''Ar e a of Stabil ity". All dra inage f rom t hi s basi n outfalls t o Che rry C r eek Interc e pte d s tom1 water 1s discharged in over 24 separate storm dra in age outfulls into Cherry Creek Som e of the more major o utfall s includ e : 5 -foot x 8-foo t box culvert at Itt and N. Downin g Parkw a y 56-inch pipe at 1st and Marion St ree t 66-inch pipe from Cherry Creek Mall at U niversity Boule va rd and Che rry C reek 60 -inch pipe f rom the eas t side of the Cherry Creek Mall near St eele Street. 3 foot x 8fo o t bo x ctll ve rt in Steele Stre e t. 4 8-i n c h x 7 6 -i nc h e lliptjcal pipe in Col orado B o ul evard north o f Cherry C r ee k 66-inch p ip e at Garfi e ld Street and C h erry Creek 4 2 -in c h p ip e f rom Uni vers ity Boulevar d so uth of Cherry Creek 72 i nch pipe from Washington Street south of Cherry Creek draining 618 acre s Drainage D e ficiencies: Stann dmi.n infr astmcturc in thi s basin h as tmdcrsized outfaJ J s a:lld incompl e t e n e t wor ks o f stom1 drain late ral s. The C h e rr y C r eek North a rea (n ort h of the m all) has b ee n pron e to flooding a nd freque n t comp laint s Basin s north o f the shopping area and wes t ofN. Race Str ee t ( Basins 80, 85 90, 9 l 92 and 10 0) still comprise 270 ac res th at dra in to an existing 56-inc h storm dra in in E }51 Avenue, which o u tfalls to Che rry C reek at N Mar io n Street. Th e r ece ntl y d es i g n e d N. Unive rsity Outfall w ill r elieve t h e b urd e n of t h e stonn drain and offer a 2-yea r level of service A drai nage study call e d th e 4th Avenue-Williams to Lafayette Drainage S tudy was finali ze d in F e b mary 20 1 2 for this a rea in g r eate r detail for both the minor a nd major {1 00 -year ) s t orm events The recommendation s of thi s study have b ee n in corpo r ated into the Storm Dra in age Maste r Plan Portion s of Basin s 230 through 260 hav e been r e-di r ecte d b y pip e flo w to Che rry Creek di ve rting flo w from th e topo g r a phic l -25 Basin This creates a split-flow conditi o n that causes shal low overla nd floo ding during major stom1 events w h e r e th e stonn drain capacity is exceede d Proposed Capital Improvements: D e n ver Wate r Board n o longer u ses the p ortio n of C i ty Dit c h pip eline north of C h e rr y Creek b etwee n D e n ver Country C lu b and C ity P a r k. R e u se o f thi s lin e \Vas evaluate d for th e pote nt ial to provide stonnwater conveyanc e or u nd e r g r o und d e t e nti o n in 2003 ; however ; lt was f o und t o have very little b e n e fit for drainag e. The reac h from 8th Avenue sout h to Ch e rry C r eek h as pote ntial reu se as a s t orm drain if inl ets a re connec te d to the pip e lin e The ave r age s l ope i s 1 % in thi s reach w hi c h could pro v id e a new outfall w ith approximat ely 40 c fs capacity Howeve r half the reach (from Speer t o 51h Avenue) appears to be lower than Cheny Creek, th e r e b y c r e ating o utfall p roblems. The f o llowing projects are proposed to rai se the lev e l of service and meet cunent drain age c ri te ria : September 20/-1 Project A: Dow ning Stre e t Outfall Construct a new outfall at Downing south of Cherry Creek to tak e some b u rd e n off the existing 72inch pip e in Was hington Street draining 578 acres (DP 1760) and pro vjde a d e quate outle t s fo r exis ting sumps in the alleys s o uth of Alam eda b e t wee n Lafa yette and Franklin. Pro iec t B: Lafa vc tte Stre et Outfall Lat e rals Thi s project consists of l aterals to the Lafa ye tt e Str ee t Outfall St orm Drain cons tnt cted in 2004 (Phase I ) and 200 7 (Phas e If). It i ncludes u p s izin g the exi s tin g 2 1 -inch stonn pip e in N R ace Street to 2 7 in c h p ipe and ups i zing exis ting 12-, 15-inch stoun pipe t o 1 8-inch pip e to meet the City's criteria P roject C East 5111 A venue Outfall Const m ct a dditi o nal stonn d r ai n s in Bro adw a y disc h arging in to Cherry Creek t o alleviate kno wn pondin g probl e m s Project D : East 6th Ave n ue O u tfall Upsize th e existin g 39-in c h o utfall t o a 72-i n c h pipe Project E East Cedar A venu e E>.iend l a terals on exi s ting storm drain s into th e nei ghborhood. Projec t G : East E x po sition Improvem e n ts E x t e nd th e local s torm drain n e t w ork starting at th e exis tin g drain at E Ce n te r an d S William s, exte ndin g up stream in Cedar Vine and Expos iti on past Milwau kee Pr ojec t H: Colorado B o ulevard Outfall Constmct a new 5-f oot x box culvert o utfall in Colorad o Boulevard. P roJec t 1 : Uni versity Outfall T h e existing storm drain sys t e m n o rth ofthe Ch erry Creek Mallis often overwh elme d A new o utfall i n Uni versity i s under d es i g n for construction in 20 1 4 in o rd e r to prov id e in c r ease d t1ood prot ec tion for t h e Che rr y C reek North area. The pro pos e d impr ove m ents a r e futur e lateral exie n s ion s P roject J : 5th A ven u e Improve m e n ts Upsize exi s tin g s t onn drain sys t e m s t o m ee t th e City's criteria. Pr o j ec t K: Ba vau d Outfall Thi s project includes a 1 2-foot x 5-foot RCBC o utfall and ttunk lines inN Madison Street and E. Bavaud Aven u e and laterals e>.iending up into the ba sin as far eas t asS. F arfax Street. 1l1e concept u a l was based o n a cursory review of uti liti es, b y Huitt-Zoll ars in 20 1 2 and a reco mm e n dation to onlv c r oss Co l orado Boul e v ard once. The tmnk main in Madi so n Street was prop ose d in t h e 2009 Cherry Creek Neig hborhood Drainage Study by PBS&J ; w hich \ < vas used for reviewing t h e Hui tt-Zo llar s conce p t ual alignment. Proj ec t L: 18-inch Upgrades Existing 1 2 -inch and 15-inch pip es in 7' h and 81b A venu es are pro pose d to be up g raded witl1 J 8-inc h pip e t o meet cun e n t c rit eria impr ove conveyanc e a nd redu ce mainte n a n ce. Pag e 1 24

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0 Key Map [ 0062-01 1 [ 4 600-01 1 ,::,.
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D e n ve r Stonn Drain age Master Plan Basin 4600-02 (Cherry Creek Mall tOO-Year Alternative) Minor Stotm Event : Lafayett e Street Outfall Stonn Drain P hase I was con s truct e d in 200 4 f rom Cherry Creek up L ittle Do\vnin g Str ee t thence eas t in 3r
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0 K ey M ap ( 0 0 62 -01 ] 700 1,400 ( 0 0 63-01 ] For D e t a il e d Hydrology See T ec hni cal Ap p end ix and Wor k M ap ( 4 5 0 0 -02] L egend .... Collection System Proposed Storm Pipe Existing Storm Pipe r -. Proposed Detention ...... Boundary 1-..J Basin -+-Existing Transit Line D City and County Boundary t:-t Topographic Basin --UDFCD Study Designed Storm Improvement ...I' Boundary -.Recommendations Existing Basin 1 : 100-yr Sub-Collection --E xisti ng Surface Flow D Potential Inundation : Oth e r Municipalities NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. Pr o p ose d Pro j ec t s ._ A-E 4TH AVE OUTFALL: $15.488,679 Basin 4600-02 1 00yr Alternative Cherry Creek Mall Feet System Boundary X Proposed Pipe Area ______________________________ __________ ____ s ig n ifl-c_ an t F Io o d in g L _oc_ a ti o n _______ ______________________ P age 1 27

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D enve r Storm Drainag e Mast e r Plan Basin 4600-03 (Upper Cherry Creek) Existing System Description: This collect i on sys t e m basin con sists of 3.585 ac r es (5. 60 square mile s) a nd is one of the n ewe r d eve l o pment r egio ns of th e e ntire study area Forth is reason. outfalls generally h ave more capac ity than so m e of th e older sect ion s of the City. Nonetheless = m a n y o f th e outfa.lls do not m eet current dr ainage critCJia and l aterals need to b e e"ie nd e d further up I nto th e basin TI1e lo.wer r eac h of this basin is outside D e n ve r limit s in tl1e City o f Gl e nd a le. Th e upp e r r eac h es o ftl1 e b asin a r e in Aurora All dra inag e from this b asin outfalls to Che rr y Cree k d ow n s tr e am of th e Cherry Creek dam Most o f thi s b asin h as been d eve l o p ed into n e i gh b o rho o d r eside ntial and parks. Blueprint Denver sbm vs the e ntir e basin as an "AreaofStabi lit y". No areas have b ee n identified as A r eas o f Change This basin is c haract e rized b y smal ler tributari es to Cherry Creek v ith tr ave l path s ge n e rall y l ess tha n 1 mil e to eac h outfalL This r eac h o f th e Cherry Creek Basin includes the Goldsmith Gulch outfall : h owever the Phase I Study Area ex clud es areas t rib utary t o Gold s mith Gulch Int e rc e pt e d stonnwat e r is dischar ge d in at l east 1 9 separa te sto 1m drain age o utfalls. Major outfalls lar ge r than 36-inch includ es th e fo U owing: 54-inc h in Birch Str eet south of Cherry Creek w i t h 80 trib uta ry acres ( DP 250) 60 -inch in Cherry Street so uth of Che rr y Cree k w jth 98 tributary acres (DP 240) 72-inch in Cherry Street north of Cherry C reek with 1 35 tributa ry ac r es (DP 162 I ) 72-inch in E x position Avenue north of Ch e n y Creek w ith 599 trib u tar y acres ( DP 1 611) 4 2 -inch in Kentuck y Avenue south o f Che n y Creek w ith 4 5 tribu tary acres (DP 220) 4 2 -in c h in Mississipp i Avenue south ofCheny Cr eek w ith 248 tributary ac r es (DP t 70 I ) 3 6-in c h in H o n ey A venue south o f Cherry Creek w ith 206 tributary acres ( DP L 6 71) 4 2 -in c h through Garl an d Par k north of Cherry Cre ek w i t h 32 t ributary acres (DP 70) 3 4-in c h x53-inch e llip t ical near Niagara Street no rth of Ch erry C reek wi th 62 acres (DP 60) 72-inch in Florida Avenue north of Ch erry Cre ek w ith 532 tributa ry acres ( DP 1 55 1 ) 4 2 -in c h in On eida A venue south o f Cherry Creek w ith 41 tributary acres (DP 1 60) 60-i n c h x38-inch ellipt ical near Qu e b ec Str ee t n ortl1 of Ch erry C r ee k w ith 88 acres ( DP 20) Th e ex istin g storm drain Infra s tru ctu r e consists o f a num e rous l arge o utfall s. Priorit y impro ve m e nt s in thi s basin aJe to exte nd the l aterals f urther up into the basin priority is t o upsize outfall for th e s tandard l evel of service. No opportuniti es for r egio nal detention we r e identified in tllis b asi n Drainage Deficiencies: Loc aliz e d drainag e prob l e m s have b ee n r e p01ted accord in g to th e complaints databas e l11e mos t s i g nifi cant is locat e d in the parkin g lot o f a s hoppin g plaza on the eas t side of S Oneida n o rth o f E Tetm essee. The Cherry C reek S t abilizat ion Plan Updat e pr e pared for the UDFCD by Matrix D esig n Group in 201 1. f o und that th e Cherry Creek reach b e t we e n H o ll y Str e e t t o Qu e bec Street contains n o ti ceable channe l insta bilit y Visibl e bank e r osion channe l d eg radation and mas s was ting of th e channe l banks has a l so co ntribut e d very hig h se dim e nt l oads to the dow11stre a m reac he s leadin g t o further ins t a bili ty Also the Cheny Creek r eac h b etwee n Qtteb cc Str ee t to fliff Avenue i s the mos t not iceably d egr ad e d Lateral instabili ty has e rod e d th e channel bank s and s tabili z ing vegetatio n TI1e r e are broad sand y b ars and ve rtica l cut bank s w itb few trees and poor qualit y rip aria n vegetatio n The 2002 Inve nto ry R e port d esc rib e d 7.0 fee t of c hannel d egradation b e t wee n 1 9 7 6 and 1 990 + The exist ing chan n e l thalweg profil e i s approximately the same as th e thalweg profil e In the 1 99 1 Study but th e c hann e l i s experienci n g sig nific a nt l a t e ral m ig r atio n Man y vertical cut banks are evide nt in the area September 20 1-J Proposed Capital Improvements: Proje c t A: E. Exposition A ve nu e OutfaU Th is proj ec t includes e-"'tending laterals on exis ting outfalls and e"tending east of Leetsdal e Dri ve Th e existi ng 72-in c h outfall i s s uffici e nt for protectin g t h e res id e ntial area up to 2-year eve nt w ith th e inc01poration of the T e nn essee and On eida Sto rm Draina ge Alternative ofthe Pro posed Proj ec t C. Project B: S Holl v Street Outfall Thi s proj ec t i s a new 36inch lateral wes t of Garland Park Project D : Hon ev Wav Outfall This proj ec t includ es a new 30inch pip e and r e plac ing 21-and 24inch pip e in E. Florida A ve nu e b etwee n S Holl y Street and S. J asmine Way t o co n vey t he split flo w ide ntifi e d inS. Forest Street Outfall Final Design Report This project also includes r e placing 12 a nd 1 5 -in c h pipes w ith 18-inch p i p es Mo s t of th e major drai n age impro ve m e nt s h ave r ece ntl y been constmcted in this area. Project s E : Florida A venue Outfall This project includ es r e -rou t in g atl exist ing s tonn drain to a new outfall i n Queb ec Street north o f Cherry Creek, and ex-tension ofthe stoon drain lateral n e t work further into th e basin Larg e s tub-ou ts h ave b ee n s hovm at tl1e Cit y limit s for Aurora to Thi s project s hould b e u nd ertake n if and w h en S. Q ue b ec Street Improvement s are don e Pr oject F: On eida Str eet Outfa]] Thi s project includ es exte nsi o n of the s t onn lat era l n etwo rk to reduce pot e ntial inundation at the intersection of On eida and M exico Proj ec t G : Val e Dri ve Outfall Thi s project includ es 18-inch pip e from Gl encoe Str ee t t o E T en n essee Avenue. A new t win 30 -inch outfa ll at th e Hi storic FowMile Par k a nd a n ew 2 4-in c h pip e in E Val e D1ive to S Glencoe Street we r e co n struc t e d in 2011 Proj ec t H : Jewell Avenue Outfall A new outfall is proposed in Quebec Stre et so uth of C herry Cre ek. This pip e begins in Je well A ve nue a nd discha r ges via a 42-inch p i p e Pro iec t J: Niagara Street Outfall Thi s proj ect includ es repl acement of an existi n g 72-inch outfall w ith a l 02-inch pip e and e>.:t e ns io n of the stom1 drain lat eral n e t wo rk furth e r i nto tl1e bas in. primaril y along Qu e b ec Street. l11is p rojec t s h o uld b e u ndertaken if and w hen Qu e b ec S t r ee t Impro ve m e nt s are co mplet e d Proj ec t J: Ch e rry Creek Stabi l ization Plan Thi s project includ es nin e drop stn1ctures w ith h eig hts vary from 3 .4 f eet to 9 feet tall were proposed i11 thi s r eac h to sta biliz e th e c hannel invert Two types of bank stabilization alternative soil riprap and pre vegeta t e d coir and d ee p-root e d plantin gs were proposed inside thi s r each for protecting bank from e rosion whe r eve r i s appropriate Pag e 1 28

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c i '0 ::: .. -g !; ..., 0 0 "' 8 D 1 "- I e g i eo .?! ;;: K e y Map ,.,: .... / ......... 1 4 600-02] 0 800 1,600 Feet 1 inch equa l s 1 600 feet For D e tail e d Hy d ro l og y See T ec hni cal A pp e ndix and Wor k M a p ...... Collection Sys tem ...... Boundary 1-1 Topographic Basin "' Boundary Thalweg [ 4 500-04] [ soooo 2 ] Proposed Storm Pipe UDFCD Study Recommendations X Proposed Pipe Disconnect L egend Existing Storm Pipe Designed Storm Impr o vem ent -E x isting Surface Flow Significant Flooding Location Wind sor Lak e .... --..... ........ ......... ... ,-.. ...... Iliff& .... ...._ <(; Monaco Detention '"''"'h G u lch <(; .... ... .... -... ... ..,-4' .,..... '. Bible P'arf<"''.. [ 4601 _01 I Dcrcnlion Auro ra [ 4 60004 ] .. .......... --..._ .... ' Proposed Pr o j ec t s .... A E EXPOSITION AVE OUTFALL: $9,580,759 B S HOLLY STREET OUTFALL: $2, 09 4 ,048 .... DS HONEY W A Y OUTFALL: $1,375,256 E-E FLORIDA AVE OUTFALL: $9,255 926 FS ONEID A ST OUTFALL: $370,445 I ... ---. .... .. .... .. --.............. I .. G S VALE DR OUTFALL: $64 5,782 (' -- Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__J Area Planned Transit Line Existing Transit Line D Cit y and Count y Boundary .. ... : Oth e r Municipaliti e s D Other Counties .......... ,......... : .... ..................... H JEWELL AVE OUTFALL: $1, 5 4 9,362 1 S NIAGARA ST OUTF ALL: $12 157,436 Basin 4600-03 Upper Cherry Creek Denver Storm Drainage Master Plan P age 129

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D e n ve r Stonn Drai n age Mast e r Pla n Basin 4600-03 (Tennessee & Oneida Sump 100-Year Drainage Alternative) Drainage Deficiencies: Localized drainag e pr oble m s h ave b ee n r e ported acco rdin g to th e comp l aints database ne most significa nt is located in the parking lot o f a s hoppin g p l aza on the cas t side of S. Oneida Street north of E. T e nn essee A ve nu e whe r e a sump co ndi t ion exists. On Jun e 26 2009 a stonn o f 1 .4-i n c h es in 20 minut es and I. 7inch es see n o n rainfall map s ca used l foot of flo o ding at th e i nt ersectio n of E Florida Ave nu e and S. O neid a S treet a nd more t h an 2 teet o f wate r at the l ow point on S. On e ida S t r ee t at E. T ennessee Ave 1bis a r ea h as flooded in the p ast. Proposed Capital Improvement s: F e l s bur g Holt&. Ullevig prepar e d th e Tenn essee & On e ida Storm Drainage A lt e rnati ves Study o n February 91h, 2011, for the City and County of D e n ve r D e partm e n t of Publi c Wo r ks. In the report an 84-ineh o u tfall, following E. T ennessee Ave n ue i s tl1e s b oltest a nd tl1e m os t cost effective Th i s alignme nt was r eco mm en d e d as the m os t f eas ible alt ernative For th e M aste r Pl an Update th e T e nn essee & One id a Stmm Drain age R eport was int egrated into the prop ose d impro ve m e nt and th e b e n e fit t o t h e neighb oring propos e d system was al so evalua t e d TI1e ex i sting 72-inch o utfall at E E x po sit i o n Aven u e is in goo d condition and i s a bl e to provid e a 2 -year s torm l eve l of prot ect ion for the residential area once the T e nn essee & Oneida Storm D rainage i s in plac e The integrated proposed improvements are li ste d b e low. P rojec t C: T etmessee & On e ida Stonn Drain This project includ es a box cu lvert outfall starting a t Cherry Creek and e:\.1ending upstream into th e ba sin in E. T ennessee Street to th e s ump area at Oneida Street in or d e r t o provide 1 00-year flood protection at the s wnp and includes a.nev-,; l ateral inS. One ida Str eet Sept e mber 2 0 Pag e 1 30

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E c "' t E ci > 0 ;: I l! .8 g. :; c.' ::; 0 Vl I "' 8 D g. 1 "- e g e' 0 .?! ;:: K ey Map [4600-02 ] 800 1,600 Feet 1 inch equals 1 600 feet For D eta il ed Hydrology See T ec hni cal Appendix and Wor k Map .... Collection System ...... Boundary t:-t Topographic Basin -'Boundary : 100-yr Sub Collection System Boundary Thalweg Proposed Storm Pipe .... UDFCD Study Recommendations X Proposed Pipe Dis connect -L egend Existing Storm Pipe Designed Storm Improvement Exist i ng Surface Flow Significant Flooding Location / I I.Mildsor Lak e ___ .. [ 4401 -04 ] f f' -. Proposed Detention 1--J Basin Existing Basin 11 Potential Inundation L__J Area -+--Planned Transit Line Arapahaelfounty ,. ..... '"'-...... Iliff& .... '-. .. ........... Monaco Detention .:f!!'lh Gulch
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D e nver Stonn Drain age Mast e r Plan Basin 4600-04 (Cherry Creek Reservoir) Existing Syst .em Description: This c o llection system basin consists of 3.675 acres (5.74 square mile s). Two major stonn drainage proj e ct s Hampde n HeiglltsPhas e I (Eastman) and Hampde n H e i g hts Phase 11 (Girard) have been construct e d s ubsequ ent to the 2009 Storm Dminage JY[ast er Plan to mitigat e r e p etitive fl ooding i ssues in the Hampde n H e i g hts n e i g hborhood The r e are numerous detention basins 'v\rithin thi s collection system basin Many were con s tnt c t e d as part of the Hampd e n Town Center D eve lopm e nt in Aurora and serve to reduc e nmoff in th e l 00-year system to a r e l e a se flo w r ate of 56 c f s fi-om the d ete nti o n basin at the southwes t corner of E Hampde n Avenue a nd S. Davton Stre e t in acco rdanc e with an intergovernmental agreement b e tween D e nver and Aurora, execute d on September JOd,, 2007 (Denver City Clerk Filing No. 2007-0103 -A) An outflow h y drograph from this point (Hydrograph output Pond 201 in t h e Amended Master Drainage R e port for Hampden Town Center b y Turner Collie Braden, revi se d August t3 20 0 2) was input into th e h y drologic model from th e Hampd en Heights AreaFlood Inve stigation and Improvement Plan by M atrix Desi g n Group and PBS&J Anoth e r d e t ention basin i s also locat e d near th e int e r sectio n of Hampde n A venue and Dayton StreeL A d e t ention basin is also locat e d o n the Hampde n H eights Park at the northeast comer to the inte r sectio n of Dayton Stree1 a nd Dayton CoUtt l11e storage I discha rge relationsh i p for these basins wer e fow1d in th e Hampden Heights Area -Flood Investigation and Improvement Plan. The Ken11edy Ball Fie ld s, ncar the intcrscctio11 of S Parker Rd and D artmouth Avenue. also ha ve a d e t e ntion basin on s ite. The d e t e nt io n bas in locat e d on the Kenn e d y Ball Fi e ld s wer e n o t designe d for a l 00-yea r sto rm eve nt. In a major storm eve nL flows w ill overtop th e wes t end of the detention bas in and t1ow overland through the Joh n F Kenne d y G olf Course to Cherry Creek. The Kenned y B a ll F ie ld s D ete nti o n recei vcs nmoff from a tributary area of 462 acres throu g h a large, bjg h capacitv inl e t located at t h e in t e rsection ofS. Par ke r Road and E. Dartmouth Avenu e. Ba se d on field i t appears t h e sutface overflow from this inl e t would n o t reach the Ball Fields D e tenti o n A FL0-2D analysis indicates that the surface flo w would cross S. P a rk e r Road at the dri ve entrance approx imat e l y 680 feet n o rth wes t of th e int e r sec tion ofS. Park e r R oad and E Dart mouth Aven ue. After splitting in the private parki n g area t h e surfuce flo w makes its way back to Dartmouth Avenue and continues west. D e tail s ofthc anal ys i s can be fot1nd in th e Hydrologicmul Hydrauli c s Repnrtfor Kennedy Ball Field s Outfall pre pared by PB A m e ricas, [nc. fo r th e Cit y and County of Den ve r in Jul y 2010 Drainage Deficiencies : The Kennedy Ball Fields Hydrologic and H ydrau li cs Report prepared b y PB America s, in c for the Ci ty and Cou nty of Denver in Jul y 2010. concluded that a I 00yea r outfall sys t e m from the K e nn e d y Ball F ie lds d e t e nti o n bas i n be constructed (see B asin 4600-04 l 00-Year Alt e rna t ive for more infonnation) Thi s s tud v also noted that runoff. which exceeds the capacity o f the sto rm drains in S P a rker Road, w ill b e wes t along E. Avenue. The s torm drain system beginnin g just south of the intersecti o n of Parker Road and Dartm o u t h A ve nu e is unde r s i ze d for handling th e 2-year flows eve n with th e K em1e d y Ba11 F ie ld s D e t e nt io n Basin. An area of approx im ately 4 62 acres (DP 250) drain s to the uppe r portion of the system and an area of 63 7 acres (DP 280) drains t o the l owe r portion of the syste m The uppe r portion oftbe sys t e m con sists of 54-inc h stonn pip e w ith capacit y for 249 cfs. Th e 2-year flow for this r e a c h i s 314 cfs. Th e lowe r p o rti o n of th e syst e m i s also a 54-inch storm pipe v ith a capacity o f 279 cfs and a design flow for the 5 -ycar eve n t i s 451 cfs. September 20 I-I Cherry Creek is the major drainagewa y through this stud y basin Per the Matri x 20 ll Orerry (reek Stabiiization Plan Update. Reach 7 ex1 e nd s f rom Havana Street to the outl e t of the Cherry C re e k Dam w ith an average channel slope b e t wee n s tru ctures of0.24%, but i s expe1iencing degradation du e t o clear water scour. The chauue l invert lower e d three feet from 1 976 to 1 99 1 at Havana Str eet. An additional o n e foot of degradati o n has occurred s inc e 1991 Drop #27 was r ecently constructed in 2009 b y r e-fac ing th e o ld K e nwood Dam outlet stntcture and creating a new plunge pool. Dow11stream fro m this pool th e channel i s experi e ncin g degradation particularl y after the flu shing r e l eases from th e Cherry Creek Dam each year b y the USACE. Proposed Capital Improvements: Project A: 1 8 -In c h Upgrades This project includes upsizing various pipes to th e C ity s I 8-inch minitnum diameter is proposed to meet current drain age criteria. Project E : Dartm o uth A venu e Outfall The 54 l n c h /60-i n c h /66 -inch /72 -incb syste m In Dartmouth Avenue cast of Cherry Creek needs t o b e improve d to con vey a 2-yea r flow of 3 14 cfs in th e upper reach es and a 5-year flow of 451 c f s in th e lower reaches Several of the un dersized reaches of pipe in t his system are propose to be ups i ze d Pag e 1 32

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0 K ey Map South Ulster Detention I "'I 1 \ [ 4 601 -0 1 ] \ l f "'' j i <:; "'' I I Rosamond: Park ,,.. oeten X n I 850 1.700 For Detailed Hydrology See T ec hni cal Appendix and Work Map .... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Storm Pipe UDFCD Study Recommendations Aurora A rapahoe County Pr o posed Pr o j ec t s -+-A 18" UPGRADES: $2,045,608 .,._ E DARTMOUTH AVENUE OUTFALL: $2,915,859 Existing ,. -Proposed Detention -+Existing Transit Line Basin 4 6 0 0-0 4 -.J Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatl on g City and County Boundary cherry creek Res e rv 0 i r -Existing Surface Flow L.__J : Other Municipalities Feet Proposed Pipe Area 1 inch equals 1 ,700feet Thalweg X Disconnect Significant Flooding Location -+-Planned Transit Line [:!Other Counties Denver Storm Drainage Master Plan P age 133

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D e nver Stonn Drainag e Maste r Plan Basin 4600-04 (Kennedy Ball Field 100Year Alternative) Existing System Description: Cmrently the John F. Kennedy Park i nclude s a p ubl ic golf course a nd an athletic sports complex The John F K en nedy M u nic i pal Golf Course consist s of a n e ight een ( 1 8 ) hole course and the sports complex J oh n F Kenne d y B a ll Fields. includes eight (8) ball fields and open space. J ohn F Kennedy P a rk is a p a rc e l ofland ctttTentl y zo n e d 0-1 primarily retail se r v ic e and office space. A s stated e arli e r th e curre n t use for th i s parc e l is recreational faci lities for use b y the general publi c. Th e pottlon ofthe parc e l that e n compasses tl1e ball fields and situated northeast of Cheri) Creek is approximately forty-three (43) acres (ac) in are a. The existing Kenne d y Ball Fie lds D ete ntion as id entifie d in City and County of Denver StOJm Master Plan as detention facilit y 271 w hi c h i s drain e d b y the existing 24-ineh outfu.IL and i s con veyed north to t h e syste m in Dartmouth Avenu e The exi s tin g cond iti on r e q uires a 46.5 ac-ft of d ete nti o n vo lum e t o contro l th e I 00-year flo w Drainage Deficiencies: The wate r sh e d was evaluate d for the City and County of D e n ve r b y PB Americas, Inc in a r e p o rt d ate d Jul y 20 l 0 and e ntitled Kennedy Ball Field$ Outfall Hydrologic am/ Hydraulic$ R eport. Bas e d on available information the existing storotwater detentiot1 fa cility h as been in existence since 1 9 7 6. With th e d eve l o pm ent of t h e Broad s t o ne Apartment Complex. a b e rm was con s tn1 c t e d to prevent pot e n t ial stormwater ove rflows from impa c tin g the site and th e multi famil y residential area southwest of t h e project s it e. The d e t e ntion basin and b erm wer e not includ e d in the uses wi thin the l ease h e ld by D enve r Parks from the Unit e d States Arm y Corps of Engineer s (USACE). [t was agreed b e t wee n United Stat es Arm y Corps of En ginee r s (USACE ) and the C ity and Cmmty of D e n ve r that th e storage vo lum e w ith in th e Kennedy Ball Fields would b e limit e d to th e appro,dmate vohm1e below th e constntc t e d b e rm o r 6. 7 a cre-feet (ac-ft) Proposed Capital Improvements: Th e drainage patterns tlibutary to tl1e K e nn e d y B all Fields w ill r e m ain unch a ng e d from th e exi s ting to proposed condi t ion lmd e r this study The propos e d impro ve m en t s wilJ include a 72 -inch RCP out fall t o convey the ma..Jmum o utflo w of 464 c fs t o Cherry Creek through the Keruledy Mm1icip a l G o l f Course. The h orizonta l ali g nm e nt o f the pro po se d outfall fac ility w ill b e position e d to minimi ze impacts to t h e gol f course and City and County of D e nver's bik e I p e d est rian path. Th e wate r qualit y/o utlet structme w ill be designed t o accommodate the existin g 24-inch RCP outlet pip e and the proposed 72-inch RCP outfu.ll The o utfall of the s y stem into C h e rr y Creek vvill include a modified HEC-1 4 Colorado State University (CSU ) rig id batlildar y basin energy dissipater that i nco rpor a tes UDFCD grouted bould e rs As of this report th e projec t has b ee n d es ign e d and i s awaiting funding fo r constructi on. September 20 1-J Pag e 1 3 4

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"' :a "l1 E "' > 0 I 1 g. :; c.' :; 0 Vl I 0 ;:;: K ey M a p South Ulster Detention 4 I I ., I ( >f .,... .. [ 4 601 -01 ) Rosamond / Park Detentitfn _, I I I
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D e n ve r Stonn Drain age Master Plan Basin 4601-01 (Lower Goldsmith Gulch) Existing Syst .em Description: Thi s porti o n of G olds mith Gulch ba si n has a total drainage area of about 4 04 s qu a r e mil es. 1t i s the lower portion of Goldsm i th Gul c h from 1-25 and 1 -225 to Cherry Creek. The basin i s l ocated i n the south east D enve r m etropolitan area wi thin the City and County of D enve r The m ain stream of Goldsmith Gulch starting f r o m Orc hard Road and continuing n ortlJward is tributar y to Che rry C r eek The conflue nce w ith Cherr y Cre e k is l ocated near Monaco Boulevard Th e entire ba s in exte nd s from Cherry C r eek about 8 miles south east to Arapahoe Road Seventeen roads and hi g h ways cross th e g ul c h a long w ith the Hi g h Line Canal Drainage Deficien c i es: Man y impro ve m e n ts and regional d e t e ntion facilit ies have b ee n constructed on G o ld s mith Gulch that have minimi ze d th e fl oo d hazard risk to structures. On ly a few stmctures are locate d the flo o dplain. Localized drainage p ro blem s occur in the residen tial area w ithin basin s 590, 610, 440 and 360. Chronic flooding i s r eported in the parkin g lo t o f a partm e n ts Jocated downstream of the existing d e tent ion basin at E .lliff Avenue a nd S Monaco Street Park way. Increased capacit y in t h e d ete n tio n b asin located within Bibl e Park was in ves tigat e d and rejected due to lack of community s u p p01t A locali ze d sump conditi on exis t s inS. Monaco Street Par kway south of E. Evans A venue Additionally c hroni c flooding has occurre d on the west side of S. H o ll y Street b e tween E E vans Avenue and E. Jc-vv e U Avenue. Drain age improvem e nts have been designed a nd \Viii b e construc t e d in 2014 Proposed Capital Improvements: Thi s bas i n requires improvem e nts primarily to up s ize the existing storm drain syste m from a 2 year capacity to a 5-year capa c ity. Project A: 1 8-i n c h Upgrades This pmjcct requires seve r a l ex; stin g storm drains t o b e ups izc d \o\ri.thin t h e basin in orde r to m ee t D e nver's stormwate r criteria Project B : E Iliff Aven u e This project includes up s izin g the existi n g lateral in E. Evans between Leyden Street and S Monaco Street Park way. Thi s up g rad e i s r equired to meet th e City s r e quir ements for service to a comm e r c ial a r ea. Simi larl y, a new storm dra in w ill be e.'.1ehded along E. Iliff Avenue from Kea.me y Stree t east t o S Monaco Street and connect to the existin g sto rm dra in system that outfa ll s to Goldsm ith Gulch The system wi ll e>.1end upS. Monaco Street Parkway and connect to the proposed storm drai n in E Iliff A ve nue Thi s system is r e quir e d to meet the C it y and Coun t y of D e n ver s minimum r equire m e n ts for commerci al areas Project C: S Monaco Stree t Parkway Improvements Tlu s pro ject requires a new 30-inch stom1 drain t o extend south along S Monaco Street Park -way t o E. Girard Avenue The sys t e m s w ill me e t D e n ver's m i nimum criter ia for both r es idential and conm1e rc ial devel o pm e nt s .')' eptember 2014 Projec t D : S. T amarac Dri ve Impro ve m e n ts A 2 yea r capacity syste m i s r e qu i red to adequate l y drain th e r es id e ntial area. A 24 -in c h l ateml w ill b e extende d t o the south along S Uinta Str eet. A 48-inch stonn drain w ill b e eAiende d to and a lon g S. Tamarac Dri ve to t h e north The storm drain w ill outfa ll to Goldsmith Gul c h at E Ke n yo n A venue and S Tamarac Dri ve Project E: E Dartmouth A ve nu e Impro ve m ents Thi s project requires up s i zing th e exi sting 4 2 -in c b s t onn dra i n to a 54-i n c h stonn d rain from its outfull at G olds mith Gulc h to S Tamarac Dri ve, and upsi zing the exi sting 36-inch sto nn drain, in T a m arac D rive to a s t onn drain offe rin g 2-year capacity to adequate l y d!'ain the r e sidential area Pag e 136

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0 Key Map ----800 1.600 For Detailed Hydrology See T ec hni cal Appendix and Wor k Map LLJ [ 5000-02] ...... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary Arapahoe County I (},. .. (
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D e n ve r Stann Drai n age Maste r Pla n Basin 4601-02 (Middle Goldsmith Gulch) Th e Goldsmith Gul ch Collect ion System Basin e n compasses an area of 7 .8 square miles f r om A r apahoe Road nort h wes t to th e confluence wit h Cherry Creek. Man y channel improvements have be e n comp l e ted along Golds mith Gulch to reduc e the potential of flood dama ge. Th e channel has been sta bili ze d and regi o nal parks have b ee n constmcted in the floodplain I 00 -yeat reg i onal d e t ention facilities have been constructed a l ong the channe l in Wallace P a r k upstream of I225 Channe l s l opes are ge n e rall y mild w ith seve r al n ewe r d r op structures along th e r eac h The upper portion of Goldsmith Gulch incl ud es the recent I -25 TREX co n st ru ctio n site New stonn drain a nd detention facilit i es drain the l -225 and J -25 interchang e to Gold s mith GLdch. Existing System Desc ription : The e n t ire ba sin exte nd s from Cherry Creek a bout 8 miles so utheast to Arapahoe Road This sect i o n ofth e Goldsmith Gulch Ba sin ha s a to tal drainage area of about 1 .34 s quar e miles. It i s l ocate d in th e sout he ast D e nver metr o politan area an d is e ntirel y w i thin th e City and C o un ty of D e n ve r Infl ows show n for Goldsmith Gulch at th e City boundary are from the Upper Goldsmith Gulch Outfall Systems Planning Conceptua l D esign Report b y Moser & Associates for the UDF C D Novem b e r 2005. Th e main stem of Goldsm it h Gul ch flo ws u nd e r 1 -225 at D TC B oulevard a n d conti n ues into the Lower Goldsmith Gulc h Basin w hi c h is tributar y t o Cherry Creek Drainage D eficie ncie s: Th e drainag e faci lit ies w ithin t hi s basin a(e n ewe r with the construction of th e TREX proj ect along the l -25 and 1 -225 corridors. Th e facilit i es w ithin th e D e n ve r T ec h Ce nt e r a r e also r e l ative l y new a nd no drainag e problems have been identified. Propose d Capital Impro ve ment s: No sto nn drai n capi tal jmpro ve m e n ts are prop ose d for this basin. D eve l opment in t h e area i s r e lative l y recent adhering t o current drain age crite ria Major dra i nageway impr ove m en t s are under th e juri sdic tion of th e Urban Drain age & Flood Contro l District and have n o t b een e-valtaa t ed ttnder thi s Master Pl an. September 2 0 Pag e 1 38

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Key Map 0 600 1,200 Arapahoe County Cherry Hills Village Fo r Detailed Hydro log y See T ech n ical Appendix and Work Map [ 5401-01 1 1-(/) (..) UJ !Xl UJ :::::> a (/) [ 4601-01 1 I / Rosamond I Pari< Arapahoe County .... Collection System ...... Boundary Proposed Storm Pipe -Legend Exi sting Storm Pipe ;--' Proposed Detention Basin -+-Existing Transit Line D City and County Boundary -eUDFCD Study Designed Storm Improvement Existing Basin I" 1 Topographic Basin Recommendations '"Boundary --Existing Surface Flow 11 Potential Inundation : Other Municipalities NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. [ 4600-04 1 Arapahoe County ......... ............... . . . . . . . . . . . . . . . ......... Basin 4601-02 Middle Goldsmith Gulch Feet Proposed Pipe L__J Area ___________________________________________ _____________ x ____ D is c o nn e c t _______________ ____ s _ig_ n ir ic a nt F Ioo ___ d in g L oc a tio n ____________ P Ia n n e d T ra n sit L in e ___ ______________________________ Page 139

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D e n ve r Stonn Drain age Master Plan Basin 4700-01 (Sloan's Lake) Existing Syst em Description: Thi s collect i on sys tem basin drain s to the South P latte River and i s ge n era ll y between Colfax a nd 32"d Avenues an d e>.1:ends wes t erly from the S o uth Platte River to Garri so n Street. Appro x imat e l y h alfofthe b asin (east e rn ) i s lo cate d w ithin th e Cit y and County ofDenver, w hil e the wes tern half i s 'vvithin t h e cities of L akewoo d Wheat Ridge, and Edgewatec Th e a r eas outside of D e n ve r d r a in to nvo s p ec ifi c c ro ssi ng points tmde r Sheridan .Boulevard at 24th A ve nu e a nd 1 8lh A ve nu e (S loan s Lak e Lat eral) TI1ese a r e r e f e r e n ce d on th e map as l ocations T' and ''D", r es p ect i ve l y, w ith flo w rates from th e D ece mb e r 1 977 Sloan's Lake Basin Major Drainag eway Plan pr epared b y URS Company for the UDFC D S l oan s Lak e occupie s a pp roxi m a t e l y 176 acres and is L ocated jus t cast of Sh eridan Boul eva rd I t r ece i ves stormwate r runoff from the m a j01it y of the basin and provides s i g ni fican t detention vo lum e for flooding eve nts. Below the J ake a 24inch storm drain sys t e m co n veys o utflo w from th e l ake and l ocal i ze d dra i n age to th e South Platt e Rive r The basi11 within D e n ver i s al mos t comp l ete l y r eside n t ial with th e exce pti o n o f Sloan sLake Park so m e co mm e rci a l areas along Sh erida n B o ule vard F e d era l BOltlevard Colfax Aven u e and Sp o rt s Authorit y Field at Mile High Stadium An up date to the 1 977 Sloan's Lake MaJor Drainag eway Plan is currently anticipated to b egin in 20 1 5 Drainage Defici e n c i es: S l oan s L.."lke i s effect i ve in re du cing p eak tlow rates to drainage sys t ems l owe r in the ba sin. The lak e r e du ces p eak flow ra t es fro m about 2.,.904 cfs t o 34 cfs du rin g th e I 00 year eve nt ( LOMR 9 2-08-(UOP effec tive May 5. 1 993 ) H oweve r the existing syste m b elow the l ake cannot s uffi cie ntl y handl e L ocalized stomnv ater mnoff. Th e exis tin g 24to 54in c h tmn k lin e drainin g this b asin b elow Sloan s Lak e i s tmd ersized for th e 5-yea r event fr o m t h e local drainage a r ea. TI1e 54-inc h o utfall a l ong Co l fax Ave nu e can co n vey 124 cfs w hile the 5 year d es ign flo-vv is 359 cfs (DP 1030). If d e t e ntion in the Lak e we r e i n crease d to r e du ce flows to th e lower s y s t e m th e n ee d to ups i ze the o utfall for l ocal draina ge would s till ex i st. The existing pipe in Colfax Ave nu e westofFedera l Boulevard is unders i zed for th e 5-year event. The s m all systems drai11ing 1 7th Av e nu e. w hich discharge int o S l oa n s Lake d o not adeq u ate l y drain th e roadway durin g th e 2 -year event. The existing system that w raps aroun d the eastern e d ge of Slo an sLak e and drain s 20lh Ave nu e is unders ized for the 2-year event. Proposed Capital Improvements : Pr oject 8 : N Wolff St. Outfall An 18-iuch l atera l is prop osed to pro v ide additional iuJets and drainage facilities for 17Lh Avenue. Proj ects C J a nd D : W Ave a nd W Colfa" Ave Improvements Upsizing th e South Pl atte ou tfall wi th an 84inch pipe is proposed w hil e a 42-in c h pip e i s r eco mm ended hi gher i n th e basin just below t he Sloan s L ake o u tlet facility Upst r ea m of th e Slo a n sL ake outlet ups i zing th e exi sting I S -in c h and 18-inch sto rm pipes w ith and 30-in c h pi p es i s reco mmend e d to prov i de drainage facilities up t o 1 th Avenue an d N Stuart Street. Upsizing the s t onn drain in CoJfa'( Avenue between Kno x Court and F e d eral Boul eva rd is prop osed to upgrad e the syste m to a 5-yea.r capacity September 2014 Pro jec t s C2: W 17th Ave. and W 18lh Ave lmp rovemen t s Ups i ze the existi n g 1 2 -inch a nd 15-in c h s t orm pip es in W. 17m Avenue from N .Julia n Street toN. L owell B o ul ev ard a nd from N. Irv ing Str ee t toN. King Str ee t r espective l y to meet curren t drainage criteria and reduce maint enance. Pro iec t E W. Lak es hor e Dr. Impro ve m en t s The sys t e m drai11ing 20th A ve nu e eas t of Sloan s Lake s h ould b e up sized to handl e th e 2 year event. P rojec t F : W 261h Av e nue Impro vements A 24-inc h l ateral is p r oposed in 26lh Avenue to co n vey the 2 -year s t otm eve nt. Pa ge 140

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0 K ey Map ... Jefferson County .a,.. .. .11rlw ... \ : Sloan' s Lake Lateral : :" .. .. .. NOTE: Trans basin f lows shown with a heavy black arrow are b ased on e x isting storm drain systems, not proposed drainage improvements. .... Collection System ...... Boundary Proposed Storm Pipe -L egend X 0 z z Existing Storm Pipe (' -- Proposed Detention -- Basin -+-Existing Transit Line D Ci t y and County Boundary 600 1 ,200 For D e tail e d Hyd rolog y See T ec h ni cal App e ndix and Wor k M a p .... UDFCD Study Designed Storm Improvement Existing Basin I" J Topographic Basin Recommendations '-Boundary E x isting Surface Flow 11 Potential Inundation : Other Municipalities ( 4 600 0 1 ) B-N WOLFF ST OUTFALL: $173,034 C1W 16TH AVE IMPROVEMENTS: $5,421,770 C2-W 17TH & 18TH AVE IMPROVEMENTS: $1,097 327 D-W COLFAX AVE IMPROVEMENTS: $7,575,118 E W LAKESHORE DR IMPROVEMENTS: $1,933,657 .... F-W 26TH AVE IMPROVEMENTS: $436,694 Basin 4700-01 Sloan's Lake Feet Proposed Pipe L__J Area ___________________________________________ _______________ jf ____ s _ig_ n ir ic a nt F Ioo ___ d in g L _oc_ a tio n ____________ P Ia n n e d T ra n sit L in e ___ ______________________________ P age 1 4 1

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D e n ve r Stonn Drain age Master Plan Basin 4700-01 (Sloan's Lake 100-Year Alternative) Existing Syst em Description: Sloan s L ake is effecti ve in reducing p eak flo w r ates to drain age sys t e m s lowe r in the collection s ys t e m basin Th e lak e redu ces p eak tlow rat es from about 2.904 cfs to 34 cfs du ring th e I (){)-year eve nt (LOMR 92-08-040P e ffective May 5. 1 993) H oweve r the existing syste m b elow the lake can not suffic i e ntl y handl e stonnwater r u noff from the drain age wate r s h e d b e lo w the lake Drainage Deficiencie s: Th ere i s an existing FEMA r eg ula tory flo o dplain from th e outlet o f Sloan's La ke t o the S o uth Platt e Ri ver. Th e 1 00-year regu l ato r y floo d p lain downstream of Sloan s Lak e does not inu ndate buildillgs, however it d oes tou c h some private par ce l s th e r e b y so m e tim es triggering t h e n ee d t o purch ase Flood Ins ura nce. Th e streets m os tl y cont ain fl ows b eyo nd th e capacity o f the existing stonn drain s in the l 00-year eve nt. An anal ys i s was done a s p a rt of th e 2009 Mast e r Plan updat e to determine w hat size fucilit ies wo uld b e needed in W 16t h Avenue. F ederal Bo uleva rd and W. Colfa x A ve n ue to co n vey th e e ntir e 100year flo w rate Th e l 00year flow rates u se d for th e a n a l ys is and the propo se d sizing cal c ul atio n s can b e see n in Table 1 .2 in the Technical Appendi x Proposed C apital Improvements: P rojec t s A : Sloan s Lake I 00-Yea r Outful Th e proposed facility need e d at the o ut fall of Sloan s Lake in N. Newton Street to convey th e 1 00year flo w i s a 60inch pipe into a 9f oo t x 5foot bo x culvert in 16th Avenu e and Federal Boul eva rd At Avenu e th e s iz e i s i nc r ease d to a n 11-foot x 7-foot box c ul ve r t Th ese proposed s i zes co n vey th e ent ir e I 00-yea r event wi1hout utili z in g th e capacity of th e street above. September 201-/. Pag e 142

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0 K ey Map Jefferson County NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. 600 1,200 For D eta iled Hydrology See T ec hni cal Appendix and Work Map L egend X 0 z z ( 4800-01 ) .... Collection System Existing Storm Pipe r ..-. Proposed Detention Proposed Storm Pipe ...... Boundary '-----' Basin -+-Existing Transit Line CJ City and County Boundary t:-t Topographic Basin ---UDFCD Study Designed Storm Improvement ...,/ Boundary Recommendations Existing Basin 1 : 100-yr Sub-Collection --Existing Surface Flow D Potential Inundation : Other Municipalities ( 4600-01 ) Pr o p ose d Proje c t s A SLOAN'S LAKE 100-YR OUTFALL: $14,830,043 Basin 4 700-01 1 00-yr Alternative Sloan's Lake Feet System Boundary X Pr oposed Pipe Area ______________________________ __________ ____ s ig n _in_ c an t F Io o d in g L oc a ti o n _______ ______________________ Page 143

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D e n ver Stonn Drain age M aste r Plan Basins 4800-01 & 4801-01 (Lakewood & Dry Gulches) Exist in g Syste m Description: L akewoo d G ulc h is a m a jor drainagewa y with a 16 s q uare mile watershed, and Dr y Gulc h is a nort h bank tributar y to Lak ewoo d Gul c h l11 e gulches b egin in Lakewood an d disch arge runoff into the South Platt e Ri ver at 14th Av e nue O nly about 10% ofthe total tributary area is w i t hin the City and County of D enver. L akewood Gulch h as 701 acres ( l .IO square miles) tributary. and D ry Gulch has 21 7 acres (0.3 4 s quar e mil es) tribu tary wi th in th e City and of D e n ver. T he collection system b asins are long n arrow basins rwming west to cast. gen eral l y along 6 A ve nu e and Colfax Avenue. TI1c basin s \\i thin D e n ver a r e full y built -o u t ptimaril y with ne i g hb orhood r esi dent ial, except for comme rcial a l o n g art e rial tra n s porta t i o n corrid o r s. Blueprint D e nver s hows l inear corrid o r s a l o n g Dry Gulch a nd Colfax as Areas of C h a n ge. Th ese a r e p ropo se d tran s it orie n te d imp rove m e nt s th a t a r e a nti c ipat e d in th ese basin s in th e futu r e. The resid e n t i a l n e i g hborhood is shown as an '"A rea of Stab ili t y ". A ll drainage f r o m th ese basins o u tfalls i nto t h e S o uth Platte River. R unoff generall y flows dm>n the relative l y steep road'"' ays into these major drain ageways. R e lati ve l y l itt l e stonn pipe is necessary in these basins due to the capacity of the streets t o conve. stonnwater. Inte r cepted stormwatc r in the pipes is disc harged in small. l ocal stonn drainage outfalls to t h e drainag eways The o nl y la rge outfall is a 39-i n ch drain from Colfax Avenue di schargi n g into Lakewood Gul c h at LO\.\Cll Boulevard The cond iti on and capacity of tl1e inle t s t o in tercept all the runoff is u nknown a t t his tim e. b ut i t is ass umed t h at they will pcrfonn adcq u a tcl ) w ith proper m ain tenance. Unique to th i s basin is the need to evaluate roadway bridge crossings for conveyance of the flood even t s. Urban D rainage & Flood Control Di strict bas eval u ated improvements in r wo stud ies completed in 1979 and the 201 3 Dry Gulch O S P l11e follO\ving roadway/r ailway crossi ngs occur on these drainagewa y s : Lakewood Gulch: I S h e rid a n B o ulevard 2 Wolff Street 3. Tennyson Stre e t 4 P e trv Street 5 1 01h Avenue 6. T wo Railroad B ridges 7 Knox Street 8 Federal BmLlevard 9 D ecatur Street 1 0 Canosa Street Dry G ulch : 1. 2 3 4 Sheri dan B oulevard Two Lig h t Rail Brid ges Two P edestrian Brid ges P erry Stree t September 2 0 I.J Drainage Def i cie nci es: Storm pip e deficienc i es are minimal in th i s area d u e to the r e lative l y s teep slo pes and the existing underground pipe network. C ul verts and bridges arc the greatest conce rn in these drainage b asi n s. On May 14.2007 a two-year o l d boy was swept away in Lakewood Gul c h as h e and hi s mother took refuge from hail in the Decat u r Brid ge/C ul vert. A new ope n chann el has been constructed b y the U DFCD and D e nver in order to contain the l 00 ycar flood an d eli min ate out-of-channel bank fl ooding Proposed Capital Improvem ents: l11is area represe n ts an imp o rt a n t COJTidor for the future FasT ra cks West Co rrid o r tra n s p ortat i o n system As noted above RTD. th e Citv and Count\' of Den ver and the U DFCD colla b orated to w id e n and "'reali g n L akewoo d Gul ch from N. Decatur to t h e So uth Platte Riv e r in order t o convey a nd contain th e 1 00year flood. The re i s a confin e d floodp lain relat in g t o Dry Gulch. however bridges n ee d t o be adequate l y s i ze d to e n sure t h at th e rai l fac ilit ies a r c not adve r se l y impact e d Sel ecte d impro ve m ents a long Dr y Gu l c h from ICON Engineerin g [nc. f o r th e UDF'C D 20 1 3 Dry Gul c h Outfall S ystems Plan h ave bee n prese n ted o n the fa c in g page m a p These con sist of bru1k stab ili zat ion along the waterco urse and the addit ion of anot h e r c ulvert at N. P e rr y Street, t o a dequately convey t h e I 00-yca r flood. Other minor pipe improvement s includ e the following: Project A: N Stuart S treet T o i m prove drainage con veyance o n Colfa.x A ve nue. a new outfall is p r oposed in t o Dry Gulch Thi s can b e com pleted b y connec tin g to the existing 33-i nch pip e in Col and o utfal Jing a new 48-inch in Stuart Street to 01) Gu lch. This maximizes the re-us e of exi sti n g pipe a n d improves th e outfal l capac t t) P rojec t C : 18'. U pgrad es E xis ting small stonn drain s will b e repl aced with 1 8-inc h pipe to meet cucre nt drain age criteria Other ad diti o nal drain s in the a rea would all eviate po ndin g in W lOth A venue and N. F e deral Boulevard P rojec t D : N WolffStreet To impro ve drainage conve y ance o n Colfax Ave nu e. exi st in g pip e can be r e plac e d an d a new 48-inch o u tfal l 1 s p roposed into Dry G ulch a t N Wolff S tr ee t Page 144

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Key Map 0 600 1,200 ... \ .. \.. Edgewater Sloan's Lake : Sloan s Lake Lateral ... .. ,... . Lakewood For Detailed Hydro log y See T ec hni cal Appendix and Work Map ..-. Collection System ...... Boundary 1-1 Topographic Basin 'Boundary IV> u. u. ..J 0 5 2 Proposed Storm Pipe UDFCD Study Recommendations [ 4700-01 1 Cooper Lake IV> :I: <.!> w ..J >-0:: 0:: LJJ a. 2 I(.) X 0 2 ::.:: 2 [ 4900-01 1 Legend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location r' -- Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L__J Area Planned Transit Line [ 0061-01 1 W 10TH AVE ,:II' Barnum NOOh P irk Barnum Park Lake Barnum Park I ,.....J
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D e nv e r Stonn Drainag e Master Plan Basin 4900-01 (Weir Gulch) Existing Syst em Description: Much of the Weir Gulch Collection System Basin is located to the west and upstream of the City an d County of D e nver. The upper basin originates near Alan1eda Parkwa y and Green Mountain Dri ve in Utkewood. The portion of the b asin locat ed within the City and County ofDenver is east of Sheridan Boulevard and generally li es as a long nanow basin following th e dra in ageway b e t wee n theW. Center Drive IS Sneridan B oulevar d intersection at th e southwestem en d t o the outfa ll at the South Platt e near 9'h Avenue a t the north cas t e m end. The 1 "1 Avenue Tributary and Dakota Avenue T1ibutar y arc two drainagcways w hich o utfall to Weir Gulch within the D e n ver basin Weir Gulch has many man-mad e improvements and is contained underground or in a 3-side d concrete bo x culvert open o n the s tufac e in man y areas There is littl e nati ve riparian vegetation along these flood control improvements. TI1e neighborhood has gene rall y orie nted their hou ses and yards away from t h e channel. In 2013 an updat e to the 1972 Sanderson Gulch/Weir Gulch Major Drainageway Plan (MOP) was ini tiate d b y Denver t hrough the UDFCD. The MDP contains reconunended improvements to Weir Gulch as we ll as the First Avenue and D akota Avenue Tributaties. Most of the upper and central bas in w ithin Den ver i s co mpri sed of residential neighborhoods. TI1e lower portio n of the bas in i s mad e up of commercial and industrial facilities along the South Pl a tt e Drainage Deficiencies: The 42-inch to 54inch system in Irvin g Street draining 208 tributru y acres is undersized for the 2-yeru eve nt. No major drainage complaints have been reported in this basin o utsid e the reg ulato ry floodplain due to the relatively steep g radi ent toward the receiving drainageway and lack of sumps or flat areas. This basin gene r ally m eets D enve r draina ge criteria for the 2-yea r stom1 eve nt I n r es id ential areas Flooding that occu r s along the main Weir Gulch draina gcway and t h e 1 "1 Avenue and D akota Avenue Tributaries is considered wit hin a regional drainageway tmder th e j utisdi c tion of the UDFCD and not included for analysis w ithin the scope of this r e port. Users are encourage d to r eview the 1'Veir Gulc h and First Avenue Tributmy (down strea m of Sheritlan Boulevmd) !Ylajor Drailwgeway Plan and Flood Hazard Area Delineation prepared for th e U DFCD prior to completing work along t h e main Weir Gulch drain ageway. Proposed Capital Improvements: Project A: N. Yates St. Impr ove m ents A 24-inch lateral is propo sed to provide 2 -year stonn drainage to the 4Lh AvenueNates Street residential area Project B : S Julian St. Outfall A new o utfall a lon g Julian Stree t and Ellsworth A ve nu e i s proposed to reduce loadin g to th e Irvin g Street system. The new system w ill drain the n ort h e m half of s ubbas i n 50 whil e the existi ng sys t em in I rvi n g Street will con tinu e to drain the southern half of the su bbasi n Project E : W Exposition Ave Imp rovements Small 18-inch to 24 -inch lat era l s ruc proposed in Utica and Xavie r Streets t o i mprove lo calized drru n age In the vicinity of :-..-posit ion Avenue. September 20 Project F: W. l $t Ave. Improv e m en t s A 24-inch lat e ral is proposed along lst Av e nue that turns north along N. Ha zel. that transitions to a 30-inch pipe to outfall at Weir Gulch and 31 Avenue Page 146

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K ey Map Jefferson County [ 0064-01 ) -+-Existing Transit Line D City and County Boundary NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. Proposed Projects _,..A N YATES ST IMPROVEMENTS: $1, 088,812 .... B-S JULIAN ST OUTFALL: $2,237,488 .... E W EXPOSITION AVE IMPROVEMENTS : $643,900 .... F W 1ST AVE OUTFALL: $978,495 Basin 4900-01 Weir Gulch

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D e n ver Stonn Drainag e Mast e r Plan Basin 5000-01 (West Washington Park) Existing Syst .em Description: This c ollec tion system basin cons ists of 788 acres ( 1 23 s quar e mil es) and is fully built-out w ith older n e ighborhood r es id e ntial in the upper r eaches a11d comm e r c ial in the lower reaches. Blueprint Denver s h ows th e commercia l a r eas wes t of Broad way as Areas of Change.' The r esi d e n tia l n e i g hborho o d i s s hown as .. Areas of Stability"' All drainage from tl1is basin outfalls to th e South Platt e R ive r Int e r cepted stonnwater is discharged in at leas t 1 4 s t onn drainage o utfalls, w hich are comprised of the following : 3-1 6-foot b y 7-fo o t CDOT concrete box culve rt s for th e Dakota A venue Outfall and futur e A lam eda and Santa F e outfall 54-inch and 66 -iu c h break in C enter Street ( proj ected) t o th e S o uth Platt e Ri ve r 42-inch for the I-25 & S anta Fe int ersec ti o n 30-inch for the Santa F e & Alameda inters ectio n 30-in c h for the Alameda & 1-25 int e r sectio n 36-inch for the Santa Fe & Kalamath inte rsection 30-inch for the Santa Fe & Kalamath int e r sectio n 2-24 -in c h for lo c al 1-2 5 drain age 2-18 -in c h for local 1-25 drain age 3-15 i n c h for lo c al 1-25 drain age The stonn drain infrastmcture consists o f a d e tail e d network of lateral s in most st reets A grid patte rn of late rals i s collect e d in P ennsy lvania and Broadway streets The inl e t s arc old sandstone/granite catch ba sins \Vitl1 limit e d capac ity due to d esig n and num e rou s asphalt overla y s throughout tl1e year s As impro ve m e n ts and handic a p ramps are in stalle d in the n e i g hb o rho o d these inl e ts are bein g replace d w iili cuJTent s tandard inle t s Man y o f th ese old inl ets must b e replaced to i mprove collectio n efficiency D rainage from the J25 basin is constrai n e d by tl1e e levatio n oftJ1e S o u t h Platt e Ri ve r and 1 -25 w hich generally r educes capacity a nd creates sum p or surcharge condition s durin g maj o r s t o rm even t s Th e c r own of Bro a dway acts as a da m and adjacent prop e rties have floode d lll tl1e pa st. The City and County ofDe nver wor k e d with P a rson s Brinkerh off and th e propert y own e r s to flmd des ign and construct a 100-year o utfall th e Dakota Avenue Outfall, from Broad'v va y to the triple box cul ve rt und e r 1-25 consthlcted by COOT. Stonn drainag e eas t of Broa dway w ill b e handl e d b y the min o r stom1 systems du ring s mall e r storm events. Runoff in larger storm even t s w ould b e con vey e d in the streets to the Dak o ta Outful L in Bro a d way Drainage Deficiencies: Aside fro m th e new COOT tripl e b o x cuJvert under l -25 an d th e Dakota Avenue O u tfull t h e re mainder of th e existing drainage sys t e m has capacit y to con vey a n a ppro ximate 1-year s torm e v ent to the South Platt e River. Rainfall nmoff in excess ofthe storm drain capacity has a histo r y ofponding in flat areas and tbe swnp o n Alameda A venu e at th e Santa F e w h e r e m ajor drainage p r oblems have been expe ti e n ce d T wo la rge pote n t ia l inundation areas occur in t h e flat commercial areas due to mnoff bac k in g u p b e hind th e rai lroad and J25. Potential Inundation Areas: Enginuity co mpl e t e d th e Broadway Main Street Zoning FL0-20 a n al ys i s i n O cto ber 20 1 3 t o d etenni n e the ext ent. o f floodin g o n Broadway Olsso n Associates completed a FL0-2 0 analys i s t o d e t e tmin e th e flo w patterns fr o m eas t of Washington P a r k i n to th e park and withi n the park. TI1e a nal ysis showed that wate r docs enter th e park from the eas t during the I 00 year stonu eve n t Inad verte n t detentiot1 occurs in Smith and September 2 0 1-J Grasme r e Lakes, w hich contain the water flo wing to th e m v.tithout s pillin g and also in the central portion of t h e park Proposed Capital Improvements: Th e exi s ting lakes at Washington Park could b e reconfigur e d to act as p eaking'' faciliti es b y d e t a inin g stoml\ v atcr o nl y in m
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= i E '0 .. K ey Map lii !; 0 600 1,200 For D e t a il e d Hydrology See T ec hn ical A pp e ndix an d Wor k M a p .... Collection System ...... Boundary 1-1 Topographic Basin Proposed Storm Pipe --UDFCD Study Recommendations [ 500 0 0 3 ) 1-Vl (.!) z 2 Grasmere Lake 0 0 Vl Proposed P r o ject s NOTE: Trans basin flows shown with a heavy black arrow are based on e x isting s t orm drain systems, not proposed drainage improvements. A-18" UPGRADES: $7,284,566 BCENTER AVE COLLECTION: $3,703,694 DALAMEDA AND SANTA FE OUTFALL: $708,046 E-S GRANT ST COLLECTION: $1,255,129 F-SOUTH BROADWAY IMPROVEMENTS: $5,488,451 ;---,Proposed Detention -+-ExistingTransitline Basin 5000-01 Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatlon g City and County Boundary West Washington park -E x isting Surface Flow L._j : Other Municipalities Feet Proposed Pipe Area 1inchequa1s1 ,2 ooreet Thalweg X Disconnect SignificantFioodingLocation -+--Planned Transit line Denver Storm Drainage Master Plan "' Boundary P age 149

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D e n ve r Stonn Drainag e Mast e r P l an Ba sin 5000-0 2 (Unive r s it y and Mexico N orth) Existing System Description: This collec tion system basin is tributary to th e South Platt e River I n general this basin is located on the north side of 1-25 from E Miss i ss ippi A venue & S. Wash i ngton Street east to S H olly Street. This basin con s ist s of 1 ; 798 acres (2.81 s quar e mil es) and includ es r es id en tial and commercial prop erties. Much of th e basin has ad e quat e s to1m drains for th e 2a nd 5-year r ettLm periods but l acks ad e quat e prot ec tion for th e I 00-ycar rctum period Drainage D eficienc i es: R e p e t i ti ve tlooding occu.rs at the ball.fields at South High School. Th e stree t o n the wes t s id e of South High School receives overflow fr o m Veterans Park Hi g h flood flo ws o n Florida Avenue can e nter the I-2 5 corridor throu g h an offset in th e so und walls. The stree t flo w d e pth s in Unive r sity Bmtl evar d arc non compliant w ith D e nver criteria primaril y north oflowa Avenue. The ptimary problem in s ub-b asin 300 is th e a mount of flo w that is carried in Mexico Avenue The l ow point in th e M exico Avenue p r ofil e i s a t Madison Str ee t. Stonnwater flo ws d o not r e l ease from this l ow p o int until th e d e pth of pondin g is hi g h e nou g h to flo w southward t o Mon tana Plac e w h e r e th e can co m e back to th e C ook Street intake sump. The break in the sound wall near the Cook Street i n tak e a llows for excess flo w to e nt e r th e J-2 5 corridor w h e n the capac i ty ofth e Cook St reet intak e stmcture has b ee n s ur c harged I n sub-basin 400 b e t wee n Evans Avenue and Warre n Ave nu e th e r e are non -co mpliant d e pth s o f street flooding Th e 42-inch storm drain in J ewe ll A ve nu e i s und e rsi ze d Potent ial I n undati on A r eas: An area of p o t entia l inundati o n h as be e n identified w ithin s ub b asin I 00 at the int e r section of Tennessee and Franklin n ear Washington Park P onding occurs for stom1s in excess of the 5-year sto nn and seve ral h o m es aro und the intersection could be linmdat ed durin g a 1 00-ycar storm. Proposed Capital Improvements: Project A: Dahlia St. and Asbutv Avenue Th e D a hlia Str ee t lnte r ce ptor b egins at the exi s ting 48 stonn drain at Dahlia and J ewell and upstream in Dahlia to Asb ury then east in Asbury to S. Franklin St Project B : Mexico Avenu e 18 an d RCP collectors are prop ose d in Florida A ve nu e and Iowa Avenue to m eet street flow criteria f o r th e i n i tial s torm Project C: So u th High School D ete n t i o n Install 1650 lin ear feet of 48 RCP and inlets in Florida A venue east of South High Sc ho o l and Gay l o rd Street to meet criteria for the initial sto nn (2 -year ) For th e s t o rm ( 1 00-year) the pr o pos e d proj ec t invo lves d e t e nti o n at South High S c h oo l. 15 acre-feet of storage for the 1 00-year eve nt i s r e quir e d at S o uth Hig h School. Th e o utl e t from th e d e t e ntion bas i n i s a 60-l nch that connects to the Lafa ye tt e intak e s tructur e in Florida Avenu e. September 2014 Proj ec t D : 18-Inch Upgrad es Upsiz ing various pipes to th e City' s 18inch minimum diam eter is propo se d to meet current drainag e criteria Pag e 1 50

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K ey Map 0 650 1,300 For D eta il e d Hydrology See T ec hni cal A pp en di x and Wor k M ap ( 4 600-02 1 ..-. Collection System ..... Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe UDFCD Study Recommendations [ 4 600-03 ) ( 5000-03 1 \ I ; [ 5200-03) Pro posed P r o ject s NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. ... A DAHLIA STAND ASBURY AVENUE: $3,154,585 ...,. B MEXICO AVENUE: $1,252,228 ... C-SOUTH HIGH SCHOOL DETENTION: $11,292,379 ... D18" UPGRADES: $1,871,063 .----.Proposed Detention -+-ExistingTransitline Basin 5000-02 -.J Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatl' on g City and County Boundary university & Mexico North --Existing Surface Flow L__J : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s 1 3 ooreet Thalweg X Disconnect SignificantFioodingLocation -+-PlannedTransitline Denver Storm Drainage Master Plan P age 151

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Denver Stonn Drainage Master Plan Basin 5000-03 (University and Mexico South) Exi sting System Description: This collect i o n svsrem basin is triburary ro the South Platte River and is l ocated alo n g the cast bank bcrwccn E Evans A and 1-25. This basin -consists of 1.464 acres (2 29 square mil es) and includes residentiaL industrial and commercial properties. For the 2005 Storm Drainag e Master Plan Sellards and G1igg utilized Smith Environmental, Inc (SEI) to cond uct a search of federaL state and local e n vironmenta l databases for the area w ithin tl1e University and Mexico Basin to identify sites where hazardous substances, petroleum products and other deleterious substances ma y have released or disposed. TI1ese environme nt al conditions h ave tl1e potential to impact the design and con str u ctio n of storm drains detention basins a nd assoc i ated structures. The r a dium di s posal s it e SW S hattuck C h e mical Company at 1 8 05 South Bannock Street has b ee n rcmcdiatcd an d th e aqu i fer w ill be monitored t o veri f y that ground wate r contaminants naturall y attenuate in the soils over tim e. TilC grOt mdwatcr plume e:'\1cnds in a n011hwest direction towards O ve rland Lake. The major contam in ants of concern are uranium a nd molybdenum The existing sto n n drain t h at parall els Santa Fe Dri ve is a l so known to contain contaminated water, possibl y from groundwater infiltration' itbin the Shattuck plume area. It is recommended that any UC\Y storm drains i n stalled '"ithin or near the contaminant plume be fitted with seals to prevent grow1dwater infiltration Creati ve Civil Solutions comp l eted a detailed analysis for t h e 1 00year storm event east of S Washington Street. The findings wer e docume nted in the Major Basin Flow Stut(v D eve lopment #20 12D00f!38. J anuary 4 20 1 3. The h ydroloro from the Creati ve Ci vi l Solutions analysis as not in corporated mto this Maste; since th e plan s focu s is the 5-year stonn event. The existi n g conditio n s h y drolog y from the South Broadway R eco n struction: Arizona Avenue to i owa Avenue Final Drainage R eport by Carter Burges s in November 2007 was incorporated into this Master Plan hydrology. Man y improv e ments to the Broadwa y stonn drain n etwork ha ve r ece ntly been constructed. Both the South Broadwav Reconstruction from Arizona Avenue to Iowa Avenue and d1e Flonda Out fall west of Broadwa y. designed by Ja cobs in J anuary 20 I 0, ha ve been co n structed The South Broadway Reconstructi o n from Iowa A ven u e to W eslcy A ven u e. d esig n e d b y TSH in Feb mary 2011. h as also been con s truct e d. The Iowa A venu e Extension Phas e L desi g ned b y the City a nd Count y of D e n ver in March 2013. has been constructed a nd in c lud es 54inch to 60-inc h stonn drains in Logan St reet from Asbury Avenue to Iowa A venue and then in Iowa A venue from Logan Street to Broadway D1ainage D eficiencies: Broadwa v itself was the most significant damage corridor in the basin Broadwa y receives large stonn flows from th e and the street crov.'ll for Broadwa y was generally at a higher e l evation tl1an the finish floor elevations for the commercial establishments on the cast side of Broadway The result i s that the street crown in Broadwa y acted as a dam that causes immdation to tlle comm e rcial estab lishments along the east s_ide .of Broadwav for relativelv l m return period even ts. Oth e r areas of th e basin do not meet street flow c ntena for the rnajo; s tom1 event need to be upsizcd Most of the Broadway stonn drain system improvemen t s have now been constructed in tl1is basin as l isted in the existing system description section The remaining area Broadwa y R econstmction from Kentuck')l to Arizona. d esigned b y NV5 in Jul y 2013. is funded for construction in 20 15. The H arvard Gulch Floodplain e:-.'tend s int o Ba sin 5000-03 and 53 parcels located west of Santa F e Dr ive. north ofW. Asbury Ave nu e in the University a nd M exico Sout h Basin are affected Flooding i s p r edicted to September 2 0 1-J be about three feet deep and enters the basin from Major Basin 5200-0 l to the south. TI1e Harvard Gulch FHAD floodplain extends as overland flow t11rough the Overland Golf Course to the South Platte Ri vcr P ote ntial Inundation Areas: An area of potential immdation has been ide n tified at the intersection of S Williams Street a n d E Colorado Ave nu e 100-ycar runoff to the Williams Street s ump results in 4.5 feet ofpondin g in the sump An option for improving tbc flooding at the Williams Street sump would be to fonnalize the detention storage. the grading depth is limited to the elevation of th e Williams Street lateraL o nl y a feet th e ex1stmg sump elevation. Shallow detention storage wou ld encumber a large reqmre ?f several properties The area is Jikcly to redevelop in t h e ncar future due to proxmuty to the hght raJ! station and the Uni versitv of D enver. Given information of flood depths approp riate measures can be tak e n by prop erty own e r s mitigate flood damages with flood proofing Proposed Capital Improvements: Project R E. Imva Avenue Extension The E. Iowa Avenue Extension prqject was brok e n int o two phases Phas e I as described m th e exi sting svstcm description section conveys 5-ycar -Bows from sub-basi n s 8 1 3 814 817, 820 and 823 and has been Phas e II will be constructed as part of the 2014 General Storm project a nd includes a 36-inch and 42-inch storm drain in E Asbury Aven u e from S Clarkson Street to S. L ogan Street where it wlll com1cct to the rccentlv constructed 54-i11Ch storm drain An 18-incb to 24 -inch pipe is proposed to exte nd east in E. Asbury from tl1e designed 36-inc h pipe at S Clarkson Street to S. Corona Stre et. Project C E Mississippi Avenue S L ogan Street Lateral A new storm drain network is p r oposed inS. Washington Street from E. Arkansas Avenue to E Loutsiana Ave nu e to convev the 5-vea r flow s The proposed proj ect 'vvill proceed west in E. Louisiana Avenue to S Logan Street. north inS. Logan Stree t to connect to the existing storm drain in E Mississ ippi Ave nu e which can accept these flows si nce it was disconnect e d from the 1 -25 drainage system durin g the 1 25 TREX improvements. The storm drain network ill consist of 30-inch and 36-inch storm drains Pr oject D : 18-lnch Upgrades Upsizing is required for various pipes to t h e City s 18-inch minimum diameter t o meet curren t dra111agc criteria. P roject E : Sub-Basin 600 Imp rovements Enlarge the inl e t capacity inS. Milwaukee S tr ee t south of E. Colorado Avenue to prevent c loggin g a nd red u ce flood d e p t h s. R e m ove cross c ulv erts t mder rail road embankm e nt. Pro v id e an improved roadside channe l a lon g E Bucht e l Boulevard with regular series of inlets connected to t h e existing storm drainage system in E. Buc h tel B oulevard. R emove tJ1e existing 6-ft b y 3-ft box culvert outfal l from Colum bine Street Grade an open c hann e l e:-.'tension to th e T-REX soutl1east University detention basin Provide a low-head scupper type entrance to the open c h annel from Coltunbinc Street Grade an overflow spillway from the Colorado A venue detention basin to th e open channel ex1ension Modify the outlet works of the Colorado Avenue detention basin to pro vi d e a standard water quality outlet. P roject G : S Washington Street D rain (I 00-Yea r Onlv) A new sto rm drain networ k is proposed inS. Washin g ton Street fro m E. Col orado Avenue to E Flonda A venue and extending down E Florida Avenue to the existing 96-inch storm drain stu b-out at S Broadwa y to conve'' I 00 ye ar flows The I 00-vear storm drain network will alle v iate flooding problem s for businesses and prop-erties along S Pearl StreetTile stom1 drain network will consis t of 54-incb to 84-inch stom1 drains Page 1 52

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K e y Map 0 600 1 200 For D e tail e d Hyd rolog y See T ec hni cal App e ndix and Wor k M a p ...... Collection Sys t em ...... Boundary 1-t Topographic Basin '-...l Boundary Proposed Storm Pipe .... UDFCD Study Recommendations Grasmere \ Lake \ I Glen dale ...... ( 4600-03 ) P roposed Projec t s BE IOWAAVENUE EXTENSION : $ 605 085 CE MISSISSIPPI A VENUE S LOGA N STREET LATERAL: $2.033.478 D -18" UPGR ADES: $1,260,966 E SUB BASIN 600 IMPRO V EMENTS: $261,832 ...., G-S W A SHINGTON ST DRAIN {100 YEAR O N LY): $6,225,904 Existing .----- Proposed Detention -+--Existing Transit line Basin 5000-03 -.J Basin Designed Storm Improvement II PEoxitsetnintlgaiBinausinndatl on g City and Count y Boundary university & Mexico South -E x isting Surface Flow L.__J : Oth e r Municipaliti e s Feet Proposed Pipe Area 1inchequa1s1 2 ooreet Thalweg X Disconnect SignificantFioodingLocation -+-P lannedTransitline Denver Storm Drainage Master Plan P age 1 53

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D e n ve r Storm Drain age Master Plan Basin 5100-01 (Sanderson Gulch) Major Drainageway Plan: Th e 2013 Srmderson Gulc h Major Drainageway Plan and Flood Haza rd Area Delinearion ( MDP) pr epared b y Matrix D es ign Group Inc. for the UDFCD primarily add r essed impro ve m e nt s to the main channel of S and erso n Gulch. and also proposed a l 00 year collection sys t em t o convey M issi ss ippi Gul c h flows into San d e r so n Gulch,.. discussed in the 1 00-yea r alternative pages. Existing System Description: Sanderson Gulch i s located in th e southwest m e tropolit a n area throu gh p ort i o n s o f th e City and County of D e n ve r t h e City of La kew ood and J efferson Cou n ty. The Sand e r so n Gulch Watershed starts at the top of Green M o u ntain and exte nd s east to th e South Pla tte River just north of West Fl orida Avenue Th e collection syste m basin i s currently fuJly d eve l ope d a nd i s primarily residential w ith some commercia L The Sanderson Gulch Basin has a total draina ge area of app ro x imat e l y 7 6 square mil es. For this stu d y only t1ibutary b as in s to D e nv e r s sys t e m we r e analyzed which includ es approximately 5.56 square mil es. Drainage Deficiencies: D eveJopme tl t occ urr e d in this a rea of D enve r a bo u t the same time floodplain developme11t c riteria was d eve loped for the C it y Land d eve lopm ent was required t o preserve wi d e open s p aces along th e floodplains of Sande r son Gulch. H owever man y of the road way culve rt s have 10-year capacit y thereb y causing flo o din g at ro a d intersections and placing s om e h ouseholds wit hin the floo dplain Low in t h e basin near the o utfal l t o t h e South Pla tt e River. commercial and industrial d eve l opme nt in this b as in has e n croac h e d into th e gulc h. Th e existing systems drai11ing B asins 670 and 680. lo wer in th e basin at th e Mississ ipp i/Mos i e r Pla ce outfalJ are undersized for th e 5-year s torm The potential fur flo odi n g o f prop ert i es durin g the 5 year and 100-year stom1 i s hi g h due t o the limit e d capacity of th e dra inag eway. D es ign P o int 682 drains to an exis tjn g 66-in c h storm drain w ithin West M os i e r Place and flo ws east t o S S tre et and then so u th to Sanderson Gul c h l11e syste m was d es i g n e d t o co n vey 3 1 0 cfs to Sanderson Gulch. This syste m i s und ers i ze d for th e 2 year sto nn even t and in a I 0 0-year e v e nt 1.295 cfs would flow in the remnant of Mi ss i ss ippi Gulch locat e d east of S P ecos at W Mosier Pl ace. A 1 00year alternative is ide ntifi e d on th e next pages. Proposed Capital Improv ements: Structure impr ove m e nts to th e channel an d roadwa y culverts can redu ce flood h aza r d areas Propo se d improvements for th e c hann e l and road crossings are s ho w n in the Sanderson Gul c h MOP. Project A: 1 8-inc h Upgrad es This u pgrad e is r ecom m ende d to m ee t th e Cit y and Cou nt y of D e n ver s Criteria Project B : S Carlan St. Outfall Th e outfull w ill pro vide drain age to t he surrou ndin g n e i g hbo r ho o d and commercial areas The upstream portion sho uld b e sized for the 5-yea r frequency s torm The storm drain w ill exte nd along Arkansas Avenue to S Car l an Str ee t a nd will o utfall to Sanderson G ulch Proj ec t C: S. Decatur Outfall A 2-year frequency storm dra i n is req u ired from San d erso n Gul c h ups trea m to M exico Avenue and Colorado A ve nu e Lat era l s will b e requir e d at eac h intersection as s ho wn on t h e plan. Proj ec t D : S. Federal Bl vd. Outfall T hi s 54 -in c h outfal l w ill he sized to hancUc tb e 5 year frequency stonu 11te existing sto rm dmln is t md e rsi ze d due to th e surrOLmding co nun e r c ial property. Sept e mber 2 014 Pro iec t E : W. Mississipp i Ave Impr ove ment s R e quir es a propo se d drain age facil ity to serve the resi dential area i n Bas i n 670 a nd 68 0 in the min or-event. Th e up g r a d e to th e exis tin g sto 1m drain wiU provide a 5 year frequenc y s t orm dra in syste m and meet D e n ver s cri teria for th e up stream area Proi ec t F: S Quitman S t. Impro ve ment s A proposed 24-inc h stonu drain inS. Quitman w ill c onn ect t o the existi n g stom1 d r a m at Arkansas A v e nu e and ex.'tend n o rth to Arizona Street Tlu s wiU pro v id e a 2 year frequenc y s t orm drain to serv i ce the residentia l a rea. Pr ojec t G : S T ejo n St Out faJl Currently no stonu drain exists in thi s a rea t o service the r esrdc ntial and comm e r c ial areas. A 5-year capacity 48 ... inch storm drain is prop ose d Project H: S Tetmvson St. Impro ve m ents A proposed 7-foot x 4-foot b ox c ul ve rt will b e connected to th e ex i s tin g stom1 drain at Florida Avenue and S Tell11yson Street. The proposed stonn drain r e quir es upsi zing th e c:o..istin g s t o rm drain Th e new p o rtion will provide sendee to the sunounding residential area Project 1 : S Utic a Outfall The lower sect ion of thi s outfall wiU b e s i ze d for t b c 5 yea r frequency storm. This system w ill accept flo ws from Proj ec t H a nd w ill i n clu d e a new l a t eral west along Florida Avenue. Botl1 s y stems will b e size d for the 5-year frequency stor m Th e exis tin g storm drain w ithin Utica w ill b e replaced Pr ojec t J : S. Vra in St. Outfall A new storm drain an d lateral s are propo sed to se r vice t b c surroundin g n eig hb orhoo d u pstream o f the o u tfall Th is storm d r ain ca n be a 2year fr eq u ency sys t e m Proi ec t K: S. Xavier S t. Outfall Th e prop osed sto rm drain w ill ext end from Sa nd e rso n Gulch up to Io wa Avenue l11e stor m drain provide a 2y ea r l eve l of serv ic e for the residential neighbo rh ood. A lateral will be e:de nded along Ore go n Place to Zenobia Street Proj ec t L: W J ewell A ven u e Impr ove m ents The pro posed 66-inch o utfal I will upsize the exi s tin g stom1 drain s ca p aci t y in Irv i ng Street and W J ewell Aven ue. t o a 5-year capacity. New 5-year capacity storm drain is proposed t o exte nd cast along W. J ewell A ve nu e t o Federal B o ul eva rd Pr ojec t M: W Kentuck'V A ve nu e O u tfall A new outfall sys t e m i s proposed a lon g Kentucky A ve nu e to intercept nmoff fro m Basins 405 410 an d 420 l11i s s y ste m w ill b e size d f o r t h e 5y ear storm C urr ently th e r e i s n o exis tin g stom1 drain in Kentucky Avetme. Durin g the 1 00-year frequency sto rm h owever runoff from th ese basin s excee d t h e capacity in W Kentt1ck y Avenue and will flo w to Basin 0064-02 Proje c t N: H arvev P ark L ake Outfall A nev\ 30 ... inch outfall sys t em i s propos e d inS. Quitm an Stree t t o int e r ce p t flows from Bas in s 230 and 240 whic h is c urr en tl y drained b y an undersized 21-inc h storm dr ain Proj ec t 0: Mississippi Gulch Int erce ptor A proposed twin 8-foot x 6-foot and quad 6-foot x 4-foo t bo x culve rt syste m wiJl collect t h e 1 00-ycar disc har ges and connect th e proposed in let bank at Quivas and Mosier Plac e with th e main chat m e l of Sa nd e r son Gulch as detennined b y the 20 l 3 MDP f or Sanderson G1tlch. Page 1 54

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Key Map 0 Jefferson,County Jefferson County ... ........ NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements 750 1 500 For Detailed Hydrology See Technical Appendix and Work Map ..... Collection System ...... Boundary 1-1 Topographic Basin "'Boundary to <( z 0 z (/) Proposed Storm Pipe UDFCD Study Recommendations -Legend Existing Storm Pipe Designed Storm Improvement Exi sting Surface Flow [ Proposed Detention -.J Basin Existing Basin [s300-01 ] -+--Existing Transit Line D City and County Boundary ...... c:::J Potential Inundation : Other Municipalities [ 5000-03] Proposed Project s ...., A -18" UPGRADES : $4 664,740 .... BS CARLAN ST OUTFALL : $3 750 813 _.,. CS DECATUR ST OUTFALL : $2 584,481 .... DS FEDERAL BLVD OUTFALL : $3 244 029 .... E-W MISSISSIPPI AVE IMPROVEMENTS : $11,452,426 .... FS QUITMAN ST IMPROVEMENTS : $799 412 _.,. GS TEJON ST OUTFALL : $1, 074 157 ... HS TENNYSON ST IMPROVEMENTS : $10 724,806 .... JS VRAIN ST OUTFALL : $3,459, 533 ... KS XAVIER ST OUTFALL: $1, 277 122 _.,. L-W JEWELL AVE IMPROVEMENTS : $3 334,942 ... M -W KENTUCKY AVE IMPROVEMENTS : $4,591 572 .... N HARVEY PARK LAKE OUTFALL : $889 608 ... 0-MISSISSIPPI GULCH INTERCEPTOR : $6 630,258 Basin 5100-01 Sanderson Gulch Proposed Pipe Area ____________________________ T h _al_ w eg __________ x ____ D is _oo_ n _ne_ c t __________ ___ s _ig_ n ifi ca n t _FI_oo_ d in g L oc a ti on ____ -+--____ P _Ia_ n ne d T m n s _it_ u _ne __ ____________________ Feet Pag e 155

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D enve r Storm Drainag e Mast e r Plan Basin 5100-01 (Sanderson Gulch) 100Year Alternative The 2005 Storm Drainage Master Plan considered a I 00-year regional detention basin on th e prop ert y directl y dovv nstr ea m ofW. M osie r Plac e at S Qnivas Street howeve r a d e tention basin in this location would be too clos e to th e South Platte River's 1 00-year floodplain t o provide significant flood hazard reduction and infrastmcture cost savings s ince it is close to th e outfall. A Sanderson Gulch Major J)rainageway Plan (md Flood Hazard Area Delineation (MOP ) was pr epared in 20 1 3 b y Matrix Design Group Inc for th e UDFCD cospo n so r e d b y D e nv e r This plan primarily addressed improvements to the main channel of Sanderson Gulch and at the r eq uest of D e nv e r also proposed a tOO year collection syste m to convey M iss issipp i Gulch flows into Sanderson Gulch D esign Point 682 dr ains to a n existing 66-inc h storm drain wi thin W. Mosier Plac e at S. Quivas Street and flo ws east to S Navajo th e n south to Sanderson Gulch Thi s syste m was d esign e d t o convey 3 1 0 cfs to Sanderson Gulch wh i ch b y cuiTe n t modelin g, is lmd ers i zc d for eve n the 2 year min o r stom1 event allowing nmoff in mod e rate and larger stot m even t s to continue cast to J imit e d capacity syste ms dow nstr eam at S. Lipan Street and th e broad indu stria l flat areas east of S. Lip a n Street. In a 1 00year eve nt. the flow rate at D es ign Point 682 is 1 593 cfs ; with 3 1 0 cfs flo wing south to Sanderson r esulting in the r e mainin g 1 ,295 cfs continuing east from S Qui vas Street as not e d at D esign Point 99L Alternative 100 Ye .ar System; P rojec t B : West Mississippi Avenu e Impro ve ment s 'This project wo uld increase the capacit ofthe existing storm drain in W Mississippi Avenue Proj ec t C : West Mississippi Avenue Lat erals Various laterals to collect nmoff n o rth ofW. Mississippi A venue Proj ect 0 : Mississippi Gulch lnt e r cepto r Th.is altemative will route th e 1 00-year flow moo.ff directly to Sand erson Gulch through an upgraded propo sed W. Mississ ippi Avenue a nd Mississ ippi Gulch Int erce ptor outfall sys t e m The 201 3 Sanderson Gul c h MDP proposed a 1 00 -ycar stom1 inlet b ank at S. Qui vas Street and W. Mosi e r P lace on pr o p erty acquired b y th e Cicy in Septe mber 2012 ahd replacing th e existi ng 66 -inch and 72-inch diameter s toml drain wi th a twin 8-feet wi d e b y 6-feet high reinforced box st01m drain in order t o convey nmoff from th e 100year storm co1Jecting at this l ocat ion down to Sanderson Gulch 'This proj ect would be constructed onl y after impro ve m e nts are m ade to inc r ease the capacit y of th e lower portion of Sanderson Gltlch be tween S. Lipa11 Street and th e South Platt e River. Sept e mber 201-/. Page 1 56

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Key Map 1-u 2 0 1-a_ (/) 0 co 1-(/) <.9 2 > ex: 0 Jefferson,County ....... ... NOTE: Trans -basin flows shown with a heavy black arrow are based on existing storm drain systems. not proposed drainage improvements. 0 750 1,500 For Detailed Hydrology See Tec h nical Appendix and Work Map 11-u (/) <{ <{ 2 2 u 0 0 I= UJ 1----' [s300-01 ] 2 ::::> ---' <{ <{ ex: (/) ex: a_ UJ (/l (/l (/l 0 w ... l1b U! 'SfHarva. Cll ..., ,....'{ Gutc;, Legend ..... Collection System Proposed Storm Pipe Existing Storm Pipe r -. Proposed Detention ...... Boundary 1.--.J Basin -+-Existing Transit Line D City and County Boundary t:t Topographic Basin --UDFCD Study Designed Storm Improvement ..I' Boundary -.Recommendations Existing Basin 1 100-yr Sub Collection --Existing Surface Flow c:::::::J Potential Inundation : Other Municipalities [ 5000 03 ] P roposed Projects A W MISSISSIPPI AVE LATERALS : $5,006,049 B W MISSISSIPPI AVE IMPROVEMENTS: $10,055 075 0 -MISSISSIPPI GULCH INTERCEPTOR: $6,630,258 Basin 5100-01 1 00yr Alternative Sanderson Gulch Feet 1 System Boundary Proposed Pipe Area _____________________________________________ ____ D i sc o n ne c t _______________ ______ s ig n ih c an t F Io o d in g L _oc_ a ti o n __________ _________________________________ Page 157

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D enve r Storm Drainag e Mast e r Plan Basin 5200-01 (Harvard Gulch Lower Basin) Existing Syst em Description: Harvard GuJch is a right-bank tributru y of the South Platt e R.tve r drainin g a 7.4 3 square mil e bastn located in south-central D e n ver. According to UDFCD Drain age Basin D esc ription M aps (UDFCD ; 1 990) the Harvard Gul c h ba sin is s ubdivid e d in to a lo we r and upp e r ba s in d esig nated as 5200-0 1 and 5200-02 r es p ective ly. To acc o mmodat e prese ntation o f mappin g infom1ation for the Master Plan updat e the upper basin \
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0 K ey Map Arapahoe County Mt>stHarva --... rdGutch ----......... ( 5300-01 ) ..... ...... 600 1.200 For D eta il e d Hydrology See T ec h n i cal A pp en d i x an d Wor k M ap ..... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Engle w o o d Proposed Storm Pipe .... UDFCD Study Recommendations L egend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location (' Proposed Detention --' Basin Existing Basin 11 Potential Inundation L___J Area Planned Transit Line Existing Transit Line D City and County Boundary Pro p o sed Project s ..... B-E WARREN AVE EXTENSION: $1,473,129 ... E-BROADWAY RELIEF, WESLEY TO HARVARD {100-YEAR ONLY): $1,436,419 ..... F DELAWARE TRIBUTARY (SOUTH OF EVANS) : $904,805 ..... G-DELAWARE TRIBUTARY (SOUTH OF HARVARD): $1.429.395 ... 1EVANS OUTFALL: $961,635 ... J EVANS TRIBUTARY (EAST OF BROADWAY): $3,347,829 ..... K GALAPAGO TRIBUTARY (SOUTH OF EVANS): $622,857 M GALAPAGO TRIBUTARY (SOUTH OF WESLEY): $781,813 ... 0HARVARD GULCH OUTFALL PRELIMINARY REPORT: $22,182,523 Basin 5200-01 Harvard Gulch Lower Basin

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D e n ve r Stonn Drain age Master Plan Basin 5200-02 (Harvard Gulch Middle Basin) Ex isting Syst em Descr i ption: Ha rvard Gul c h is a ri, ght-bank tributa ry of the South Platt e River draining a 7.4 3 square mil e basin located i n south-central D e n ver. The follo w in g discussion fo c us es on drainage sys t e m d es cription deficiencies and propos e d capital impro vemen t s for the en tir e middl e bas in 5200-02. Land use in the 2.75 square mil e middl e basin is primarily reside ntial w ith commercial d eve l opment a long major transportation co rridors (U n ive r sity Boulevard Hampde n and E vans Avenues). Port e r Ho sp ital and the University of D e n ve r are l ocated w ithin th e Middl e Bas i n Th e s outh ern p01t io n ofthe bas i n is l ocated in unin corporated Arapahoe County City of En g le woo d and Cherry Hills Vill age. Approximat ely 2.0 s quar e miles of the Harvard Gulch basin lies outside of t h e City and C ounty of D enve r municipal bmmdary Harvard Gul c h M c Willi a m s and DeBo e r Par ks are locate d along the Harvard Gulch major drain ageway The middle basin includes t wo major drainag eways : Hanard Gulch and Dzy Gulch. The Harvard Gulch draina geway co nsi s t s of open channel d1roughout Ha rva rd Gulch Par k (from Logan Street to O g d e n Street) Upstr ean 1 of Ogd en Street to D ownjng Street i s a l4'l2' x LO. unde rgrotmd box co ndu i t. Upstr ean 1 of D ownin.g Street to Rac e Str ee t the major dra inageway for Harvard Gulch cot1sists of an open trapezoidal sec tion of con c ret e c hann el. Upstream of Rac e S t reet is a natural channe l in D e B oer Park. The D ry Gulch drain ageway i s comprised of 700 fee t of 2 parall e l 68''x 43 b y buri e d e llipti cal pipe. and 800 feet o f 72 -inch buried circular pipe c>.1 e ndin g south from H arvard Gul c h Par k to the sou t h e rn City boundary. Additional buri e d circular pipe ran g in g in size from 72-inch t o 33 -inch exten d s into Arapahoe Com1ty to Girard Avenue n car the sou t h ern boun dary of th e v at ers h e d. The S. Gaylo rd Street Outfall Sout h of H arva rd Gulch proJect, desig n e d b y the City and County o f D e n ve r in D ece mb e r of 2 00 9 was constructed in 20 I I and con sis ts of a stonn drain n e t wo rk to convey 2 y ear flo ws in S Gaylord Street from E Cornell A venue to Ha rvru d Gul c h Drainage Deficiencie s: The floodplain d e lineat e d in th e 1979 Flood Hazard Area Deline{ltion H{lrv{lrd Gulch West Harv{lrd Gulch & Dry Gu lch b y Gin gery Associates Inc. for t h e Urban Drai nage and Flood Contr o l Di stric t '"'as overlaid on the City aud County of D enve r s parc e l la yer and it was estimated that 333 parc e l s woLdd be in undat e d by the Harvard G u l ch I (}{)yea r floodplain iJ1 the m id dl e basin of H arv ard Gulch (520 0 -02) and 6 1 parc e ls in D enve r wou ld b e inundat ed b y the Dr y Gulch 100-year flo o dplain du e to majo r draina geway cap acity lim ita tion s Flo o ding is pred i cte d to b e greater tha n 3 feet deep a l ong th e e ntir e H a rvard Gulch and Dr y Gul c h drainagewa ys w ithin th e City s muni cip al bound ary. Appr oximate l y twenty p erce nt o f parcels witl1in th e Harv ard Gulch 1 00 year floodplain occur bet ween Dow11in g Stree t and Race S t reet w here th e channe l is concrete-li n e d or unde r g rotmd. Flood probl e m s are J ess fre q ue nt upstream of Race S t reet confin e d primaril y to prop e rties a d jacent to the o p e n channel. Oth e r drainag eway d eficienc ies in H arva rd Gul c h occur at brid ge c rossing s and closed condu i t inl e t s w h e r e backwat e r effec ts create tlpstr e am floo d cond i tions S eve r a l flo w restricti o n s exis t in the H arvard Gulch major drainageway that cause ove rban k I 00-year flows. Th ese inc1ud e constrictions at Mad ison A ven u e E ntrance to th e concrete trapezoidal c hrum e l at Race Street at the wes t end of D e B oe r Park September 2VU Brid ge crossings o f the concrete trap ezo idal channel from Race Street to Do w ning Street C ul vert e ntranc e at Logan Street C ulv e rt e ntrance at Do wning Street M a n y of th ese flm.v limiting faciliti es we r e size d f o r a 25-year event, but m o r e r ece nt anal y s is indicates capacities a r e close r to a I 0yea r eve n t or l ess (Gingery Associates FHAD D ece mb e r 1 979) M aste r Plan h y drologic mode ling (UDSWM) concluded that the majority o f the initial storm drain system d oes not t o meet City l eve l of service criteria. Locali ze d flo oding has also been noted at s iph o n s w h e r e capac i ty is pe1iodically restric te d b y an accumu l ation o f d e bris and se dim e nt. Proposed Capital Improvements: Draina ge impro ve m ents in thi s basin are primaril y recommended to achieve the p erfo rmance objectives as d esc ribed in D e n ve r's Drainag e Criteria ; 2-year ruJd 5-yea r systems for residential and commercial areas respecti ve l y vvit11 street s carrying d1e excess mnoff in l a rger stom1 eve n ts How eve r for th e major drainag eway c h anne l propos e d improvements s hould b e d esi gn e d t o prov id e 100ycar freqtt ency s tom1 event leve l of service to redu ce o r e liminate th e regulator y floodplain t hrough the area. A Major Dr ainageway Plan and Flood H azard Ar e a D e lin eat ion updat e has been request ed in th e UDFCD's Plant1ing Studies program TI1is stud y is currently anticipated tor fundin g in in 2015. H arva rd Gulch \Vas includ e d in the Octob e r 2009 Gulch M{Lster P/{ln b y Ma trix D es ign Group for t h e City and County of D enve r Departm ent o f Parks ru1d Recreation. Prop ose d capital impr ove ment s include: Construction of stonn drains in local r o ads shown to improve i nt e r ce ption o f minor sto rm e v ent rlllloff and conveyance within n e ighb orhoo d s. Approxim ate l y 1 500 feet of the D r y Gul c h drain ageway exte ndin g from Yal e Avenue t o Harvard A venue will be r e placed with a l 4 x 8 RCBC c o ndui t. A c o mposit e c h annel and tvvo drop s tru ctures in Harv a rd Gulch Park arc requir e d to accommodate these propo se d impro ve m e n ts. Harvard Gulc h Park to R ace consists of r eplac ing th e closed co nduit upstr e am of H a r va rd Gul ch Park f ro m O g d e n Street to Do wning Street and the co n cre t e chaiJne l from D owning Street to Race Stree t w ith a double l5'x 8 RCBC. Pag e 1 60

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K ey Map Arapahoe County 0 700 1,400 I (/) 2 <( (.!) 0 [ 5 2000 1 1 ...J (/) E VASSAR AVE For D e t a il e d H y drology See T ec hni cal A pp end ix and Wor k M ap Englewood ..... Collection System ...... Boundary 1-1 Topographic Basin "' Boundary II(/) (/) 2 <( 0 2 (/) 0 0 a:: a:: ... w o a5 u Proposed Storm Pipe ... UDFCD Study Recommendations L egend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location E E VANS AVE (' -- Proposed Detention --' Basin Existing Basin 11 Potential Inundation l.__j Area Planned Transit Line Existing Transit Line D City and County Boundary ( 5200-03 1 P r o posed Pro ject s .... A-COLUMBINE OUTFALL: $147,379 ... B-CORNELL TRIBUTARY (FLOWS TO ENGLEWOOD) : $549,744 ... C DARTMOUTH TRIBUTARY (FLOWS TO ENGLEWOOD) : $396,308 ... D DRY GULCH MAJOR CONDUIT : $5,013,393 ... E FLORA TRIBUTARY (FLOWS TO ENGLEWOOD): $1,803,725 ... G-GAYLORD OUTFALL ( N ORTH OF HARVARD GULCH): $287,805 ... I HARVARD GULCH PARK TO RACE : $22.202,259 J CORONA OUTFALL: $1,072,529 ... K-JOSEPHINE OUTFALL: $127,676 .... L LAFAYETTE OUTFALL (NORTH OF HARVARD) : $3,422,541 ... MLAFAYETTE OUTFALL (SOUTH OF HARVARD): $385,340 ... N PENNSYLVANIA OUTFALL: $91,063 .... 0RACE OUTFALL: $422.085 ... P-UNIVERSITY OUTFALL (NORTH OF HARVARD GULCH): $1,917,753 ... S WILLIAMS OUTFALL: $405,049 ... T-YORK OUTFALL: $759,367 Basin 5200-02 Harvard Gulch Middle Basin

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D e n ve r Stonn Drain age Master Plan Basin 5200-03 (Harvard Gulch Upper Basin) Existing System Description: L and u sc in 3.84 squar e mil e upp e r basin is primaril y resid e ntial with commerc ial d evelo pm ent along major tran spo rta tio n conidors (Co l ora d o B oulevar d I25, Hampden and Yale Avenue) TI1e southemp o rt io n oftbe b as in is l oca t e d in unin corpo rat e d Arapal1oe County and Cherry Hill s Village. Arapahoe County enclaves exi st along t h e eastern bmmda ry of t h e u pp e r bas i n (Holl y Hill s) and are bounded b y the Harvard Gulch dra.inagewa y Oal1lia Street. and 1-25. Approxi mat e l y 2 .0 square m iles of th e H arvard Gulch b asin l ies outsid e ofth e City and County o f D e n ver municipal b o unda ry Blueprint Denv e r h as I d e ntifi e d 168 ac r es as 'Areas of C hange" Th ese are cen t e r e d in commercial areas b ounde d by E Iliff Av e nu e S. Colorado B oulevar d I-25 an d alon g S Co l ora do Boulevard from E. Iliff Avenue sout h p ast E Amherst Avenue. There i s no indu s t rial l and u se in th e upper ba sin. The so uth and cast portion s of the b asin i s traversed b y the High Line Cana l which intercepts some initial stonn flo ws from b as in h eadwate r tributaries in the exis t i n g con diti o n H owever Section 3.3.4. 1 o f th e City a nd County o f D e n ve r s Storm Draina ge Design and Technical Criteria Manual states that Irrigation faci liti es s u c h as ditches a nd r eservoi r s s hall not be u sed as drainage faci l ities .. Because of thi s in itia l stom1 flows we r e mode l e d as b e ing conve y e d across th e High Lin e Canal t o the downstream s t orm drain n etwor k Storm drain pipes to convey the 2-year flo w in iliff Aven u e from S Bir ch Street t o S Colorado Boulevard wer e constr ucted in 201 2 as part of City and County of D enver s G ene ral Storm -Ph ase 1 project Drainage Deficiencies: The flo o dpl a in d e lineated in the 1 979 Flood Ha'{.ardArea Delineation Hmvard Gulch West Harvard Gulch & Dry Gulch b y Gingel)' Assoc i ates Inc. f o r the Urban Drain age an d Flood Co ntr o l Dis trict was overlai d o n th e City and County of D e n ver" s parce l layer and it wa s estimated th at 79 parcels wo uld b e i nund ated b y th e Harvard Gul c h 1 00 year floodplain in the upper basin of H arvard G u lch (5200-03). TI1e most press in g n eed is for an impro ve d / upsized drainage sys t e m in Yale A venue east of Col o r ado Bo ulevar d to replace t h e existing 1 8inch to 42-inc b pipe and provide and o utfall for future drains e:\.iending up stream into th e b asin This wo uld b est b e ac hi eve d after improvements t o the d ow n stream p ortions of Harvard Gul c h are co mpl e t ed in o rder t o remove prop e rtj es wes t of Colo rad o from t h e J 00year floodplain so as not to exacerbat e floodin g do v.'tlstreatu. Potential Inundation Areas: Th e City and County of D e n ver completed the 5273 E Eastman Pot e ntial Po n din g Area analysis in Ma y 20 1 2 to d etem1ine the ext ents in t h e area. A Pot entia l b1undation A rea was i dentified in S. Glencoe Street Proposed Capital Improvements: D rainage i mpro ve m ents in thi s basin are primarily r ecommende d t o ac hi eve the p erfonua o ce objectives as d escribe d in D e n ve r s Drainag e 2-yea r and 5 y ea r s y ste m s f o r r esjde n t i a l a nd comme rcial areas respectively w ith streets carryi n g t h e excess nmoff in larger s t orm eve nts. To m e e t these rcq uheme nt s mos t o f th e exis tin g stom1 drai n n etwor k wi I l need to b e replaced These impr ove m en t s can b e phased in s maller pr ojec t s following the completion ofthe m a jor pro j ect components. Pro posed capi t al im pr ovements incl u de : Sept e mber 2UU Constructi o n of stonn drain s in l ocal roads s h ow n t o impro ve int e r ceptio n of minor stonn e v e nt nmoff and co n veyance wit hin n eighborhoo ds. Yale Avenue Outfall co ns is t s o f an Llps i ze d bo x c ul ve rt a n d upsi ze d reinforced concr e t e pipe i11 Yale Avenue b e t wee n the outfall to th e open c hann e l wes t of Co l o rado Boul evard to S. Hudson Street. A reinfo r ce d concre t e b ox culvert is needed west of Colorado B o ul evard to Dahlia Street t o convey the 5-y r flo w including flo ws that currently di sc harge t o the Hi g h Line Canal An upsized pip e is n ee d e d eas t ofDal1lia Street to Huds on Street to co n vey the 5y r flow i ncludin g fl ows that cu rr e ntl y disc h arge t o th e Hi g h Lin e Canal Th e C ity and County of D e n ve r i s in the pro cess o f designing th e East Y a l e Avenue Stonn Phase I s t orm drai n impro ve m e n ts w hich includes co ncr ete box pipe in S. Gl e n coe Street from S Grape Way to East Yale A ve nu e and in E Yale Avenue from S Gl encoe Street to S Eud ora Street to mitigate repetitive flooding in t h e s ump inS. Glencoe Street south of E. Yale Ave nu e Page 162

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-e l1 :;/ ;; .. "' .,; .., 0 cl :< g i 1> .. I G a 'il 1 "2' 0 "' u: Key Map !sooo-o3] }4;-I'J.;-, E HARVARD AVE I I \ 5200-0 2 E \!ASSAR AVE ---Arapahoe County E CORNEL L AVE Engl e w oo d Ch erry Hills Villag e 750 1 ,500 Feet 1 inch equals 1, 500 feet For Detailed Hydrology See Technical Appendix and Work Map ...... Collection System ...... Boundary 1-1 Topographic Basin "'Boundary Thalweg Proposed Storm Pipe UDFCD Study Recommendations X Proposed Pipe Disconnect Legend Existing Storm Pipe Designed Sto r m Improvement -Ex i sting Surface Flo w Significant Flooding Location z 0 (/) 0 ;::) J: [ Proposed Detention -.J Basin Existing Basin 11 Potential Inundation L.__J Area -+--Planned Transit Line 14601-01 1 -+-Existing Transit Line CJ City and County Boundary ...... : Other Munic i palities [ : Other Counties Iliff & \ Mon aco \ ....... .... 4600-03] I I \ I '). ) I \ I \ \ .. \, ..... ........ \. \. \ \. ,, \ \ \ BiblePa\ \ Deten tion ':. '-. Propo s ed Project s A AMHERST OUTFALL : $798,673 _.., AASTEELE OUTFALL : $829,796 _.., BBIRCH OUTFALL : $1,947,024 ,, ..... BB-YALE OUTFALL (COLORADO TO BIRCH) : $2 752 ,599 ..... _.., C-CLAYTON OUTFALL (SOUTH OF HARVARD GULCH) : $3, 199 ,812 _.., CC YALE OUTFALL (BIRCH TO CLERMONT) : $572,807 _.., D CLAYTON TRIBUTARY (SOUTH OF AMHERST) : $1,911,249 DD-YALE OUTFALL (CLERMONT TO BROOK ) : $815 ,900 E-CLERMONT OUTFALL : $4 935 ,975 EE-YALE OUTFALL (BROOK TO DENNISON) : $891,780 F COLORADO OUTFALL (NORTH OF HARVARD GULCH) : $6,445 406 FF YALE OUTFALL (DENNISON TO DAHLIA) : $1,091,264 G COLORADO OUTFALL (SOUTH OF HARVARD GULCH) : $3,174,106 GG -YALE OUTFALL ( DAHLIA TO EUDORA) : $895 ,731 H COOK OUTFALL : $1,962,241 _.., I DAHLIA OUTFALL : $1,158 ,291 _.., IIYALE OUTFALL (GLENCOE TO HUDSON) : $1,407,404 J DARTMOUTH TRIBUTARY : $3,482,875 K ADAMS WAY IMPROVEMENTS : $524 937 _.., L DENNISON OUTFALL : $698 439 M EASTMAN TRIBUTARY (EAST OF FOREST) : $5 ,441 ,594 N-EUDORA OUTFALL : $6 330 464 PGLENCOE OUTFALL (SOUTH OF YALE) : $1, 425 ,013 Q GLENCOE TRIBUTARY (SOUTH OF HIGH LINE CANAL) : $3, 768 ,271 _.., U JACKSON OUTFALL (NORTH OF HARVARD GULCH) : $596,795 _.., VJACKSON OUTFALL (SOUTH OF HARVARD GULCH) : $361 490 \ WMANSFIELD TRIB. (FLOWS TO CHERRY HILLS VILLAGE) : $1,034, 443 XMONROE OUTFALL: $573 ,729 .. Basin 5200-03 Harvard Gulch Upper Basin Denver Stor m Drainage Master P l an Pag e 163

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D e n ve r Stonn Drain age Master Plan Basin 5300-01 (West Harvard Gulch) Existing Syst em Description: The W est Harva r d Gulch Collection S ys t e m Basin has a to t al drain age area of approximately 1 44 square mil es W es t Harvard Gulch flo ws eas t through D enve r to it s confluence with th e Sou th Platt e River and is generall y bounded b y Wesle y Avenue on the n ort!L Sh e rid a n B oulevard on th e wes t. B ates Avenue o n the south and th e South Platt e Ri ve r o n th e eas t. TI1e b asin e l eva tions rang e from 5,536 f ee t t o 5 250 feet W es t Harvard Gulch is w ithin Eng l ewoo d from P ecos t o Zuni. Th e basin i s curre ntl y full y d eve l oped w ith th e exception o f a few scattered vacant lots Rub y HiH bord ers West Harvard Gul c h direc tl y to the n ort h and Dartmoutl 1 border s West Harvard Gul c h dir ectl y to th e so uth The channel is d eep l y inci se d a nd generally contains the 1 00-year flo o dplain Few struc tur es are locate d w ithin the r eg ulat ory floodplain Drainage Deficiencies: Ba si n s I 0 and 30 totaling 54 acres drain s to an exis t ing 2 1-in c b stonu drain th a t exceeds the 2-ycar flow capacit y of 30 cfs. A rel atively flat residentia l /co mm e rcial area a l ong Yale and Amh e r st A ve nu es c u rre ntl y has n o stonn dra in facilities The existing 42-inch s torm drain inlrving Street d oes n o t have th e 2-year flow capacity of 88 cfs The existing stonu drains in S D ecatur Street S C l a y Street and Z uni Street do not have the 5y ear flow capacity. Proposed Capital Improvements: Project A: 18-inch Upgr a d es Th e upgrad es are prop ose d t o meet minim u m stom1 drain s ize c rit eria Proje c t B : S. F e deral Blv d. Impro ve m e nts An exist ing sto rm dra i n s y stem wit hin South Green Court is und ers i ze d for the 2 year stonn. A 30 -in c h t o 36 -inch 2 year ca pa c i ty stor m drain is proposed t o co nvey storm flows to West Ha rvard G ulch. Upsizing the stoon drain s shown on the plan w ithin F e d e ral Boul evar d w ill inc r ease capacity to the 5-year storm Upsizing the st01m drain s in Irving Street will inc r ease capac i ty to the s torm Pro j ec t C: S Zuni Str ee t Outfall Upsizin g the storm drain s to serve the r eside ntial and commercial areas i n Ba s ins 130 and 140 to adequate l y drain the area and meet th e City and County of D e n ve r s c rit etia The new sys t e m would b e a 5-year sto rm drain and would includ e S D eca tur Str ee t S Clay Str ee t and n. v o Z uni Str ee t outfa U s. Th e S. Zuni Street outfall ex t en d s into S Bryant Street and h as fmger s exte nding wes t in W Yale Ave nu e and W. Amherst A ven u e to convey th e 5-ycar event. September 2 01-1 Pag e 1 6 4

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K e y Map r -=-=-= = ii .. ::: co i !; 0 0 8 D lit l Q. ( 550 005 1 1<: I e g e' 0 600 1 200 .!1! <.? Feet ;;: 1 inch equa l s 1,200 feet 0 3 m z
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D e n ve r Storm Drainag e Mast e r Plan Basin 5401-01 (Greenwood Gulch) Existing Syst em Description: This collection system basin drain s to Greenwood Gulch v ia Prentic e G11lch in Green woo d Villag e The basin generally follows Monaco Street fro m Union A ve nu e on th e north to B ellev iew Avenue o n the sout h. The basin is l ocate d in tbc southwestern comer of th e D e n ve r city limit s and is generally known as 'The 165 Subdivision. Th e basin is prima1il y comprised ofbusiness and comme rcial buildings w ith lesser amotmts of multi-famil y r eside ntial in the no1th part o f th e basin Th e r e i s a n exi s ting gol f cou r se in th e eas t part o f th e basin Th ere are major existing storm drain tmnk sys t e ms in M o n aco Str ee t that convey flo ws from the cast to thr ee se parate detention basins on th e western edge oftbe basin The storm drain system br anches up Bell eview Avenue and Union Avenue Approximate l y half of th e basin is c urr e ntl y und eve l ope d and d eve lopm e n t p l ans arc underway. The fom1er Mo u ntain View G olf property i s currently b e in g developed as partofthc Bell eview Station Tran sit Orie nt e d D evelopme n t proj ect. The gol f course is being developed iJ1to very hi g h d e n sity r esidenti al com m erci al and r e tail parcels Drainage Deficien c ies: Tbestotm drain system in Monaco Street appears adeq uat e for conveyi n g flows to th e exis tin g d c tcnti ott basin s. Th ere a pp ea r to b e no significant drainag e probl e m s with the systems. Proposed Capital Improvements: Th e r e are no r e quired impro ve m e nts for tillS basin September 201-1 Page 166

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K ey Map 0 600 1,200 For D e t a il e d H y drology See T ech ni cal Appe ndix and Work M ap Cherry Hills Village .... Collection System .._.Boundary 1-1 Topographic Basin "' Boundary Proposed Storm Pipe UDFCD Study Recommendations L ege nd Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location ) Rosamond I Park [ 4601-01 ) Deten/lon \.. r I Proposed Detention Basin Existing Basin 11 Potential Inundation L.__j Area Planned Transit Line Existing Transit Line D City and County Boundary \ \ .... Basin 5401-01 Greenwood Gulch

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D e n ve r Storm Drain age Master Plan Basin 5500-01 (Bear Creek-Fort Logan) Existing System Descaiption : Thi s collection sys tem basin b eg in s at the confluence of B ear Creek w ith t he South Platt e River. Th e western si d e o ftl1 e basin is bound e d by Sheridan Boul evard. The basin e:\.1end s north and south from th e bank s of Bear Creek. Travel di s tances arc generally l ess than 1 Yz miles. Much of the upper bas in is co mpri se d of r esiden tial n e i gh b o rho ods. Fort Log an comprises m uc h of the central porti o n of th e b as in F o rt Logan includes cemetery facilities und eve lop e d trac ts and th e m edica l facilities cent e r e d around t h e int e r sectio n of Lowell Boul evard and Oxford Ave nu e. Much of th e lower portion of the basin is located w ithin the Cit y of Sheri dan. The lo we r portion of the basi n i s made up residen t i al areas and commercial and in dustr ial fac iliti es. Drainage Deficiencies: Th e Utic a Street Ston11 Drain ( DP 380) h as capacit y for the 2-year event; however flo ws are backi n g up against the embankm ent for Harnpde11 A venue w arrantin g a 5 -ycar syste m in t h is locati on. The system draining Basi n s 400. 420. and 430 ( 1 80 a cres) in Knox Comt is undersized an d cannot convey the 5-year flo w of218 cfs (e l e m e nt 1430). Th e sys t e m currently has capacity for approximately 100 cfs. E>..1en s i ve p o rtio n s of r eside nti a l areas in the n orthwest area of the basin la ck fom1alized s t orm drain systems Th e roadways arc relat i ve l y s t eep allowing for good s t o rrnwat e r con veyance but nuisan ce flo ws traveling long di s t ances could po se a probl e m Proposed Capital lmpi"ovements: Project A: 1 8Inch Upgrades This p r o ject up sizes vario u s pipes to tl1e City s 18-incb minim um di a m e ter is proposed t o m ee t cu rr e n t drainag e criteria. P ro ject B : S Kn ox Court Upgrade The existing 42-inch di a m e ter stonn drain in S Knox Court is propose d to be up g rad e d t o 60 -inch diam e ter from W. H a mil ton Avenue toW. H a mpd en Avenue. Project C: S. Utica St. Impro ve m e nts A 66 i n c h storm drain i s proposed along W. Hamilton Place t o collect the excess flow that cannot be co n veyed b y the ex isting 60-inch storm d r ai n c ro ss in g of Hampton Aven u e at Utica Street An 8 4-inch stor m drain is propose d t o r ep l ace the existing 54-inch s torm drain a t Ral eig h Street a nd Hampton A ve nu e to accept the increased flow w hich is di verted from U tica S t r ee t through the propo sed 66-inc h s t orm drain The prop ose d syste m w ill pro vide a 5-year l evel of serv ic e Project D : W Amherst A ven u e Imp rovements S m a ll 18i ncb l atera l s are pro po se d along Amherst Avenue Stuart Street and Patt o n Court t o convey nui sance flows through residential areas Project F : Vrain Street Impr ove m e nts An existing pip e at the north end of Vrain Street shou ld be up s i zed to a 42-iuc h syste m to co n vey the 2 year event t o Ft Logan Cemet ery. September 201-1 Pa ge 1 68

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K ey Map [ 0065 -01 1 0 700 1 400 Fo r D eta il e d Hydrology See T ec hni cal A pp end ix and Work M ap I I i I I County I ...... Collection System ...... Boundary a-t Topographic Basin '-...l Boundary .. ( 006 5 -02 1 NOTE: Trans-basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. ...... ALCO TT S T BYRAN T ST Proposed Storm Pipe .... UDFCD Study Recommendations ... 1 oo67 -01 1 Arapahoe County .,.. B S KNOX CT UPGRADE : $4 77.128 .,.. C S UTICA ST IMPROVEMENTS: $1,321,491 .,.. D-W AMHERST AVE IMPROVEMENTS: $2,811, 906 .,.. F VRAIN ST IMPROVEMENTS: $1, 278 885 Existing .----. P r oposed Detention -+-Existing Transit Line Basin 5 50 0-0 1 -.J Basin Designed Storm Improvement Existing Basin g City and County Boundary F 0 rt L 0 g a n -Existing Surface Flow D Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 4 ooreet Thalweg X Disconnect SignificantFioodingLocation -+-PlannedTransitline Denver Storm Drainage Master Plan Page 1 69

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D e n ve r Stonn Drain age M as t e r Plan Basin 5500-02 (Upper Bear Creek) Existing System Descl"iption : Thi s collection sys tem basin drain s to Bear Creek and is ge n era ll y bo u nd by L ake ridge Ro a d in Lake\Yood o n the no rth Quincy Avenue o n the sout h W adswo rth Boul eva rd on t h e wes t an d S herida n Boule var d on th e east. The lan d usc within tbc bas in is co mpri sed of a mi>.1ur c of sing l e fami l y r eside n tia l multifamil y r esi d en tial co mm ercial scho ol par ks a nd P i n ehurs t Cou nt ry Clu b Drainage Deficiencies: The m a j ority of tbis b asin i s n ewer construc t ion compare d to othe r areas of D e n ver. Mos t d e ficienci es are r e l atively min o r and cau se onl y nuisance flow pro b lems Proposed Capit a l Improvements: Pr o j ect A: 1 8In c h Upgrades Upsizing vario us pipes to th e C i ty s l 8-inc h minimum di a m e ter i s proposed t o meet cummt d mi n age criteria P ro j ec t B : S Newland Stree t Outfall A 24 inc h t o 36 -inch sys t e m is proposed in New land Street to convey nui sance flows through r esiden t ial areas Project C : S Sherida n Blvd Ou tfall A n ew/ups ( zed outfall is proposed in S h e r idan Boulevard exten din g up to Yale Ave nu e Th e syste m will co n vey the 2-yea r stom1 throug h mostl y r eside n tial areas Pr o j ect 0 : S. Webster St. Out fall Collecting a large t rib utary drai nage area f rom a n u n d eve l o p e d p ortion of L akewoo d the exis ti ng sto nn drain in Webster Street s h ould b e ups i ze d and exte nd ed f rom a 30-inch sys t e m t o a 6-foo t x 4-foot RCB C The pro pose d s t orm drain will better serve b oth r esidentia l a nd comm e r c i al areas eas t of W a d swo rth B ouJeva r d P rojec t E : W B a t es Ave hnprove m e n ts M inor l a t era l ex1en s i o n s are pr oposed along B ates Ave n ue to a ddre ss localized stree t flows in resi dential a r eas. Pr o j ec t F : W. D art m o uth Ave. Impro ve m e nt s A minor l block l a teral ex t e n sion is proposed a l ong Dartm o uth A ve nu e from S. G ray Street r o S H o b arr to add ress l ocal i ze d street flows in r esi dential areas September 201-1 Pa ge 170

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0 Key Map .,....-." _... ---'-..... .. ....... .. ...... ., '-....... ----, \..... -..--, .. ... \I'J cOL\.)l'/IB\P-. PL W COLGAiE Pl ... ,ru oARiMOuiH AVE ( 5501-01 1 .. : ...... .. ( 5500 -031 650 1,300 For Detailed Hydro log y See T ec hni cal Appendix and Work Map ...... Collection System ...... Boundary 1-1 Topographic Basin 'Boundary Proposed Projects _.. A-18" UPGRADES: $863,815 _.. B S NEWLAND ST OUTFALL: $2,462,590 Jefferson County C S SHERIDAN BLVD OUTFALL: $5,001,597 D S WEBSTER ST OUTFALL: $3,750,879 Proposed Storm Pipe UDFCD Study Recommendations EW BATES AVE IMPROVEMENTS: $995,857 _.. F W DARTMOUTH AVE IMPROVEMENTS: $271,653 Existing .Proposed Detention -+Existing Transit Line Basin 5 50 0-0 2 --' Basin Designed Storm Improvement Existing Basin g City and County Boundary u p per Bear creek -Existing Surface Flow c:::J Potential Inundation : Other Municipalities Feet Proposed Pipe Area 1 inchequa1s1 ,3ooreet Thalweg X Disconnect SignificantFioodingLocation -+-PlannedTransitline [:!othercounties Denver Storm Drainage Master Plan P age 171

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D e n ve r Stonn Drainag e Master Plan Basin 5500-03 (Academy Park) Existing Basin Description: The Academy Park Tributar y Watershed is a de ve loped area in the southwestern p o rt io n of the D enve r m e trop ol itan area adjacent to the in t e rsection o f Wadsworth Boul eva rd and Hampden A ve nu e (Highway 285) Three governmental entities ; the City of Lake woo d the City and County of Denve r a nd J effe rson County eac h have _jw1sd.iction over a port io n ofthis waters h e d Wadsworth Boul evar d and Hampd e n Avenue are both very larg e streets in this are a and both serve as drainag e boundari es l11e wate rsh e d covers an area of a ppro>..im ate l y 382 acres The H e nry' s Lak e Drainage,;.. ay crosses throl.lgh the wate rsh ed i n pipes "vhich run under Wadsworth through the north wes t corner of the watershed and unde r Hampd e n A ve n ue These discharges are shown .as trans-basin f1ows into and back out of the co llection syste m basin as determined by tbe J uly 1 999 Academy Park Tributcrry to Bear Creek Outfall Systems Planning Study b y Kiowa Enginee rin g for th e UDPCD l11e Warrior Ditch e nt e r s th e wat e r s h e d in a sip h o n that crosses und e r Wadsworth just south of Jeffe rson Aven ue. and exits the wa t e r s h e d n car Col orado Acad e m y. The a rea s west of Pie rc e Street and south of Hampd e n A ven u e are mo s tl y commercia l developme nt. a nd the a r eas east of Pi e rc e Street and north of H a mpd e n Avenue have d eve lop e d as single-fa mi ly r es id ential a r eas. Drainage Deficiencies: The waters hed has three defined outfalls The fir s t outfall s y s tem drains the areas enclosed b y Wadsworth Boul evar d. T e ll e r Street. Hampd e n Avenue. and Mansfield Street. a nd outfalls to the H e n rys Lak e D rainageway just before it i s conveyed under Hampd e n Avenue. The second outfall in the wat ershe d drain s th e rest of th e area south of Hampd e n A venue and west of Pi e rc e Street to the intersectio n of P ie rce a n d Hampd e n Avenue l11e third o utfall drains the areas east of Pi erce Street and sou th of Hampd e n Avenue Th e drainag e concentrated at eac h ofthese point s n orma ll y reaches Bear Creek thro u g h a system of suffic i ent capacity to carr y the stormwater from the a reas south ofHampd e n Avenue durin g large nUloff eve nts. The capacity ofthe H e nry's Lak e Drain ageway d ownstream of Hampden Avenue is limit e d b y the existing pipe w1de r H ampde n Avenue Stonnwaterflows during small events from areas upstream of th e Warrior D i tch are int e rcepte d b y the dit c h and conveyed o u t of the wate rsh ed to th e east. Runoff excee din g the ditch capacity flo ws n o rth along P ie rc e Street. The existing d e t e ntion facilities in the wat e r she d are not included in t h e base lin e h y drolo g i c mode l as tb ey are not publicl y owned o r maintain e d Proposed Capital Improvement s: The maj ority of t his basin lies outside the City and Cow1ty o f D enve r w ith only th e outfall l ocated w ithin tl1e City b o undari es An i mpro ve m ent project has r ecent l y b een constructed at the o utfaU a nd no further impro ve m e nts are proposed w ithin D e n ve r September 2VU Pag e 172

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Key Map ... .. I / ................ .... .._ __ ..... ---' ....... _. _____ &. ........... ........ -....... ......... ...... Lakewood ........ ...... .. .. . . . . . . .. .. . .... Jefferson County ( 5501-01 ) Henry's IJJke ...... (Kio w a 9 9) .. .. Lillie L ake Henry Jefferson County Bow Mar NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems, not proposed drainage improvements. r /. \ ... ..... : r .. .....

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D enve r Stonn Drainag e Mast e r Plan Basin 5500-04 (Bear Creek-Marston Lake North) Major Drainageway Plan: Marston Luke North /)rainageway Major J)taina geway Plan (MDP) was co mplet e d b y Olsso n Associates for the U DF CD in 20 12. Thi s pla n primaril y addressed impro ve m e nts t o th e main chan n e l of the Mar s ton Lak e North Draina geway but a l so propo se d upda te d s torm draina ge impro vements in the vic init y of th e prop ose d Gl en bro ok D e t e n tio n Basin (see Proj ect B b e l ow) and othe r recommendations for disconne cting stonn wate r discha r ges to the B ow l es Lateral rrriga:ti o n Dit c h that tra ve r ses th e drainag e b as in Existing System De sc ription: Thi s collect ion sys tem bas i n drains to Bear Cre e k via the M ars t o n Lak e No rth C h anne l and is gene rall y b ound b y W H a mpd e n A venue on the north W Kenyo n Avenue o n the east W B ellev iew Avenue on th e and S. Ne l so n Street in J effe rson Co u nt y o n the west. Th e majority of the basin i s l ocated in D e n ve r wi th th e wes t e rn edges l yi n g in J e fferson County. The B ow les Lateral crosses th e ba sin from the northwest co m er to th e soutl1eas t comer. eve ntuall y flo wi n g into Bo w l es R eservo ir No l S evera l s t o rm drain s di sc h a r ge into the Bow les Late ral, whic h flo ws ro u g hl y 80% full in tl1e s umm er. The r e is a concrete weir adjace nt to th e ditch near Gar Way that di verts overllow from t h e ditch to the storm drain syste m that disc har ges into Lakes Lak e Lak es Lak e i s in th e n orthern portion of th e b asin w ithin Stanfo r d and Balsam P ark. Th e Mar ston Lake North Channel originates at S Kipling Street in Jeffer son County n ort h ofW. Stanford Avenue en t e r s D e n ve r nearS Garrison Str eet. and flows east to a dete nti o n basi n o n th e eas t side ofS. Wadsworth B o ul evar d th e n run s a l o ng th e north s id e of Mar sto n Reservo ir. eve ntuall y dj sc h arg in g int o Bear Creek. Mult ip l e s t orm drains throughout the b asin convey flo ws to th e Marston L ake North Ch ann e l The b asin is co mprised o fprimaril y r esi d e nti a l n e i g h bo rho o d s w ith c omm ercial/ r eta il areas locate d n ear Wadsworth B oulevar d Drainage Deficiencie s: Several of th e b as in s drain directl y to th e Bo wles Lat eral. To avoid potential disputes wit h th e ditch co mpani es co n ceming water rig ht s and possible under gro undin g of th e dit c hes, i t would be p r eferable t o c r eate a sto1m drain s ys t e m ind epende nt of th e Bo w l es Lat e ral. Th e 36-i nch storm drain svste m draining D es i g n P oint 1 38, leadin g t o th e G l e nbroo k D e t e ntion B asin. is und ers iz e d Th e 4l-inch stom1 pipe al o n g th e wes t side ofS. Wadsw01ih Way, between W Layto n Avenue (DP 117) an d th e Mars ton Lak e North Draina geway (DP 117) h as the capac i ty t o co n vey a p proxi m a t e l y 90 c fs. w hil e the 2 yea r and 5 yea r flo ws are 97 cfs an d 1 4 3 cfs. r espective ly. On April 1 1 2005. th e prop erty at 4693 S Ho yt St reet was floode d w h e n the s torm w at e r d ete nti o n b asin b e hind the home overto pp e d Damage consisted o f .floodi n g in the backya rd water e nt ering th e house fl owing through the dinin g a r e a a nd into the lo wer d en, bedro o m bathroom an d cra,v l s p ace. TI1e kitche n was also fl oode d and snowmelt flowe d arow1d both sides o f t h e h o m e and thro ug h the gar a ge. Proposed Cap.itallmptovements: P ro j ec t A: South Wadsw orth Wav Impro ve m e nts Thi s project inc r eases the s i ze and/o r capacity of th e sto1m sys t e m in Wadsworth fro m Union Avenu e t o th e Mars ton Lake North Chann e l. September 2VU Proj ec t B : Gle nbrook D e t e ntion Basin & S. Garrison Stree t Improvem e nt s Impro ve drainage from S. Kipling Street to the Gl e nb rook D etent ion Ba s in and disco nn ect the Glenbrook D e t e ntion Basin o utflo w fr o m the B ow les Lat e ral Ditch with a n ew s t orm drain outlet in S. G a rri so n Str eet from the Gl en bro o k D e t e nti o n Basin t o the Mar ston Lak e North Dra in age ... vay. Also as n o t e d in the facing map ex t en d th e 30-inch pipe th a t c urr e ntl y discharg es into th e Bo w les Lat e ral Dit ch near Fie ld Way and Wagontrail Driv e west t o th e new stonn drain sys t e m inS. Garrison Street to di sconnec t fr o m th e Bow les Late ral Ditch Upsizc the exis tin g 1.5 a c -ft d e t e ntion basin in Wagon Trai l Park with a new 6. 7 a c -ft natur a l areas d e t entio n and wate r quality ba s in A 48-inch o utl e t RCP i s t o b e b uilt from th e new d eten t io n basin north in G a rri son Street to an exis tin g manhol e in Stanford Avenue. The existing 36-inch RCP b etwee n th e exi s ting manh ole in Stanfo rd Avenue and the Marst o n Lak e North Dra.inag eway i s to b e u p s iz e d to 48-inch RCP IS-foot x 3-foo t RCB C /6-foot x 3-foot RCBC and the ex i st in g outfall to Marston Lak e North Drai n ageway t o be re-bui l t a s r e quir ed Pag e 174

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Key Map 0 850 1,700 For Deta il ed Hydrology See T ec h n i cal Append i x and Work Map Lakewood .... .-. Collection System ...... Boundary 1-1 Topographic Basin 'Boundary [sso1-o1 J County (/) [ 5901-01 l Proposed Storm Pipe UDFCD Study Recommendations Henry's Lake """'"'I I L egend Existing Storm Pipe County Bowle s Rese!Voir No 1 (' Proposed Detention -.J Basin Designed Storm Improvement --Existing Surface Flow Existing Basin 11 Potential Inundation L__J Area Significant Flooding Location Planned Transit Line [ 0067-03 ] Marston Reservoir Proposed Projects Arar>ahoo County Bow Mar 1 oo61-o2] NOTE: Trans -basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements. [ 0067 01] Littleton A S WADSWORTH WAY IMPROVEMENTS: $1,792 266 BGLENBROOK DETENTION BASIN & S GARRISON ST IMPROVEMENTS: $2,380,349 Existing Transit Line D City and County Boundary Basin 5500-04 Marston Lake North

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D e n ve r Stonn Drain age Master Plan Basin 5500-05 (Pinehurst Tributary) Existing Syst em Description: The Pin e hur st Tributary Watershed i s a mostly developed area in th e southwestern portion Den ver wes t of Sheridan B oulevar d and m ostly south of Hampd e n A venue Three govern m e n tal e ntit ies: th e C i ty of L akewoo d the Cit y and County of D enve r and J efferso n County e a c h have j uri s dicti o n over a portion of the \v atershed. Th e coJiectio n s y stem b asi n co v ers an a rea of approx imat e l y 4 5 1 acres (0 71 s quar e mil es). Land use co n sis ts of si ngl e fami l y r eside ntial multif amily r es id e n tia l commercial sc ho o l and Pin e hurst Cow1try C lu b and golf co ur se The existing major dr ainage syste m consists of sto on drain s and open ch ann e l in th e a r eas from Quinc y Street do wnstream across the golf course The nmofffr o m thi s up stream drain age sys t e m i s conveyed to Woody's Pond l oca t e d so u t h east o f Co l o rado Academy. W oo d y' s Pond drains to a stonn drain that runs d O\Jl Harlan Stree t t o the upstream end of a n open c hann el. The c h a nn e l the n nm s t hrou g h some pri vate prop e rti es and the Tall Pin es and P e bbl e Creek apartment complexes. From the downstream e nd of the open c hannel th e nmoff i s c arri e d in a 48-inch pip e u nd e r High w a y 285 to Bear Creek. T\ 0 s mall e r outfalls exist in the bas i n : a 30-inc h storm drain alon g F e nt o n Street and a 24-inc h pip e draining a p o rtion of the Tall Pin es apar tment co mpl e x The re co mm enda tion s of the 1 999 Pinehurst Tributary to Bear Cr ee k Outfall Systems Planning Study (OSP) prepared b y Kio wa Engineering for th e UDFCD. have b ee n in corpora t e d into this report t o address f utur e development an d prev iou s l y propo se d drain age improvements Drainage Deficien c ie s: H istorically. draina ge pro blems ha ve b ee n identified along H a rlan S tre et eas t o f C o l ora d o Academy. The sto rm drain co n veyance system do w n s t rea m (n ort h) ofWoody's P ond was und ers i ze d and has cau se d flooding t o seve ral h o m es al o ng Harlan Street d u rin g events greater than th e 5 -year frequenc y. Proposed Capit a l Improvem ents: In order to address known tloodi n g issues along Harlan Street impr ovemen t s have b ee n r ece ntl y constmcte d o n the Co l o rado Academy property wes t of H a rlan Str eet. A second d ete nti o n b asin was constructed a t the northeast come r of the pro p erty, and an a ddition a l storm drain has be en installed wes t of H arla n Street. Other minor improvements we r e mad e to local dr ainage s y ste m s .in th e are a O t h e r impro ve m e nt s r ecom m e nd e d in the 1 999 P i n e hur s t Tribu tary OSP h ave bee11 incorporated h e r ein: P rojec t s A. B C and G : F oot hill s GC lmpro ve m en t s and Pie rc e Wav D ete ntion Upstream ( south) of Colorado Academy. improvements t o a n existing berm are propo se d to protect the P i n eh ur s t Vill age U con dominittm complex Th e b em1 is l ocated on th e golf course prop erty an d w ill be owne d and mainta i n e d b y the Pin e hur s t G olf Course D evelop m e n t r e lat e d d e t e ntion b asins are propose d within the Cities of Lak ewoo d and De nver i n t h e u pper r eac h es of th e basin Small co n duits and open channels are prop ose d to dra i n th ese detention facilities across th e golf cour se to th e m ain channe l. These imp rove m ents are to be d evelo pment dri ve n September 2UN Projects D. Rand F : S. Harlan St D e t en tion Small o n-lin e d ete n t ion basin s are propo se d along th e Pin e hur s t Tributary so uth of Hampden A ven u e The basins were p roposed in the 1 999 OSP study and w ill attenuate p eak flo ws to t he Hampde n Avenue crossing a nd the existing 48-iuch o utfall to Bear Creek. Pa ge 176

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Key Map e I 5 : a; I v 0 !?) g i-l Q. I e g 'g 0 i5' .!!! 600 1.200 Feet ;:: 1 inch equals 1 200 feet ........... ___ ...,_ -.... .. -. --" ..... .... .. . ( 550 1 -0 1 1 HeTYy' s Lake Fo r Deta il ed Hydro l ogy See T ech n ical Append i x and Work Map Jefferson County Little Lake Henry ... :: ...... Collection System ...... Boundary 1-1 Topographic Basin Boundary Thalweg Proposed Storm Pipe --UDFCD Study Recommendations X Proposed Pipe Disconnect ( 5500-03 1 Marston Reservoir [ 0067-03 1 Legend Existing Storm Pipe Designed Storm Improvement -Existing Surface Flow Significant Flooding Location (' Proposed Detention --' Basin Existing Basin 11 Potential Inundation t_____j Area -+--Planned Transit Line -+-Existing Transit Line D City and County Boundary ...... : Other Municipalities D Other Counties [ 0067-01 1 Proposed Projects ... AFOOTHILLS GC IMPROVEMENTS: $2,310,920 Basin 5500-05 Pinehurst Tributary Denver Storm Drainage Master Plan Page 177

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D e n ve r Stonn Drai n age Mast e r P l an Ba sin 550 1 -01 ( He n r y's La ke ) Ex isting Syst em Descr ipti on: Henry' s Lak e Collection S ys t em Basin lies w ithin th e so uth wes t portion of th e D e n ver M etro p o litan area and is a tributary to Bear Creek. The H e nry s Lak e B as in drains gen e rall y in a northeasterly d i rection Th e upper end oftbe basin is located immediately west of Kipling Street at Quin cy Avenue. The contluen cc with Bear Creek is l ocate d jus t eas t of Pierce Street. Th e bas i n is rural l arge lot r esi d e nti a l and h as no definitive channel Th e basin area tributary to B ea r Cteek i s 1.36 square mil es (86& acres) Th e total length of th e basin 1s a ppro xi m ate l y 3.58 mil es for a s lop e of 7 5-fee t p e r mil e (1. 4% ) Th e draina geway li es a lm os t e ntir e J y within tb e City o f L a k ewoo d and J effe rson County A s mall p01t ion oftbe wate r s h e d near Henry's Lake lies wit hin th e C i ty and County of D enver. H enry s Lak e b as flood s torage. of approxlmatcJ y J 8 acre-feet and affords co n side rable do w nstr eam pro tec t i on and flood p eak r e duction Th e g r ea t est redu ct ion in peak flows occurs for th e mo r e f r e qu e nt s torm s (2t o 10;.'ears). Henry's Lake i s a l so very effective as a d e t e nti o n fa c ilit y for th e extre m e events (50 to 1 00year). Drainage Deficiencies: Two inigatioJ1 ditche s tra verse th e study area, th e Warri o r Ditch a n d th e Marston L ake North Channel. The dit c h es carry int egratio n wat e r b etween th e basins adjacent to Henry's Lak e B asin. Th ese discharges are shown as tra nsb as in flows out of and back into th e b asin as d ete nnin e d b y the July 1 999 Academy Park Tributary to Bear Creek Outfall System!t Planning Study b y Kio w a Engineering for th e UDFCD Urbanization of th e basin ha s r esulte d in in c reas e d nmoff collec t e d b y the dit c h es and subs e quent overtoppi ng. Some o f the ditch has b ee n piped but a substantial p ort i o n of th e Warrior Ditch remain s o p en channel. Th e draina geway consists o f a 76-inch x 48-inch Hori zo ntal Elliptical R e inforc e d Concrete Pip e (HERC P ) culve rt beneath H a mpd e n Avenue The 72 -incb x 44-in c h CMP b e n ea th Wadsworth Bo u levard di sc h a r ges into an open top co ncret e vau lt ( bubb ler'') Exiting fr o m t h e vaLtlt i s a s mall e r 48-inch RCP storm d rain. Durin g th e m o r e inte nse sto nn s. th e h ea d wate r at the Hampd e n Avenue culve rt overtops th e f r o nt age road causing a flo w s plit to the east. P r oposed Cap i tal Improvemen t s : No improvements are propo se d for this basin w ithin th e C i ty and County of D e n ver reac h September 201-1 Pag e 178

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Key Map e I ... 0 a -g E .8 0. I 0. "' 0 ., I v 8 ..... ....... .... __ i 0. I G a 1l 1 e-0 600 1 ,200 (!) Feet u: 1 inch equals 1 ,200 feet ........ ... . . . ......... Jefferson County Harriman Lak e .......... ..._ J ..... For Detailed Hydrology See Technical Appendix and Work Map .-. Collection System ...... Boundary 1-1 Topographic Basin Boundary Thalweg .. ., .. -.............................. Proposed Storm Pipe --UDFCD Study Recommendations X Proposed Pipe Disconnect Legend Existing Storm Pipe H enry s Lake Designed Storm Improvement Existing Surface Flow Significant Flooding Location '----...... ... ". ............ 1-(f) (f) z 0 <( r Proposed Detention --' Basin Existing Basin 11 Potential Inundat i on L__J Area -+--Planned Transit Line .. .. ...... .. a = 100 cfs O s = 1 55 cfs a,co= 16 0 cfs ...... ( 5500-03 ) -+-Existing Transit Line D City and County Boundary ...... : Other Municipalities D Other Counties ( 0067-03 ) M a rston Re servoir NOTE: Trans basin flows shown with a heavy black arrow are based on existing storm drain systems not proposed drainage improvements ( 5500 04 ) Basin 5501-01 Henry's Lake Denver Stor m Drainage Master P l an Pag e 179

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D e nver Stonn Drain age Master Plan Basin 5901-01 (Coon Creek) Existing System De scl"iption : This co11ection s ys tem basin drain s to Coon Creek and is generall y bound b y Belleview A ve nu e on the north Sheridan B oulevard on th e east, Bo w l es Avenue on t h e south and Kiplin g Street o n th e west The majority of the basin is locat e d in J effe r so n County and t h e Denver city limit s line zigzags in and out of th e basin Coon Creek flows in a south easte rl y direct i o n thro u g h th e midd l e of th e bas in Tiuee major r ese rvoirs are located w ithin th e b asin: Bowl es R eservo ir No. I Grant B R eservo ir and Grant C Reservoir Th e b asin is comprised o f a mi x of residential n e i ghborhoods w i t h commercial/retail a r eas lo cated ncar the arte rial roadways, a golf course a large baJlfield complex, and several reservoirs Mos t of t h e flows are co n veye d direct l y t o Coon Creek v i a relativeL y small stoon drain sys tems in the roadwa ys. Bas in s 60, 6 1 and 64 drain t o Grant B Reservoir, Basins 62 and 63 drains t o Bowles R ese 1voir No 1 and Bas in s 70, 71 and 72 d r a in to Grant C Reservoir. Since only a sma11 portion of the basin is in D ertve r there are fe w D enver-ow n e d publ ic outfa1ls. Between Estes Street a nd W a d swort h B oulevard there are several o utfalls int o Coon Creek. From the north the r e are a 12-in c h o utfall an 18-ineh o utfall a 24-inc h outfall, and a 36-inch outfall; from the south there are two 18-inch outfalts and two 30-inch outfaUs. There are several pipe n e tworks within the City and County of D e nver that dis charge int o Gran t B Reservoir and Grant C Reservoir. A few pip es that drain directly to th e Bowles Reservoirs are owned and maintain e d by o th ers Dtainage Deficiencies: Devel o pm e n t in tl1is basin i s r elat ivel y new. Th e r e appear to b e n o significant drainage p roble m s witl1 th e s y s t e m s l ocate d w ithin th e City and County of D e n ve r Th e Dutch Coon Lilley Gul c h ami Thre e Lakes Tributary Major Drainageway Plan and Flood Hazard Area Delineation Phase B prepared b y PBS&J for the UDFCD in 2008. did n o t ide nt ify any needed improve me nts for the p ortio n of Coon C reek w ithin D e nver (Reach 12 ). Proposed Capital Improvements: The r e are no required improve m ents for thi s bas in "'ithin th e City a nd County ofDe nver. Sept e mber 2 01-1 Page 1 8 0

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Key Map Glenbrook Del. Pond [ I 6'a (Designed) 5500-04 ........ ... 0: f..... ..... "' .. "< 1:! ,.. "< '\..-... 0 0 1-C/l >w -' a :::> a [ 0067-03 ] Marston Reservoir -+-Existing Transit Line D City and County Boundary Bow Mar Bowles Lake . .. Upper Tule Lake ... Littleton Basin 5901-01 Coon Creek

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D e n ve r Stonn Drain age Master Plan September 201-1 This page left intentionally blank. Page 1 82