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Urban drainageways, an aesthetic approach to design

Material Information

Title:
Urban drainageways, an aesthetic approach to design
Creator:
Takeuchi, Lin M
Publication Date:
Language:
English
Physical Description:
volumes 166 pages : illustrations, maps, plans ; 28 cm +

Subjects

Subjects / Keywords:
Drainage -- Planning ( lcsh )
Drainage -- Planning -- Colorado -- Denver Region ( lcsh )
Landscape architecture ( lcsh )
Landscape architecture -- Colorado -- Denver Region ( lcsh )
Drainage -- Planning ( fast )
Landscape architecture ( fast )
Colorado -- Denver Region ( fast )
Genre:
bibliography ( marcgt )
theses ( marcgt )
non-fiction ( marcgt )

Notes

Bibliography:
Includes bibliographical references (pages 161-166).
General Note:
Submitted in partial fulfillment of the requirements for the degree, Master of Landscape Architecture, College of Design and Planning.
Statement of Responsibility:
by Lin M. Takeuchi.

Record Information

Source Institution:
University of Colorado Denver
Holding Location:
Auraria Library
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
15525123 ( OCLC )
ocm15525123
Classification:
LD1190.A77 1986 .T33 ( lcc )

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Full Text
Urban Drainageways:
an aesthetic approach to design


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THIS THESIS IS SUBMITTED AS PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR A MASTER OF LANDSCAPE ARCHITECTURE DEGREE AT
THE UNIVERSITY OF COLORADO AT DENVER COLLEGE OF DESIGN AND PLANNING GRADUATE PROGRAM OF LANDSCAPE ARCHITECTURE
ACCEPTED:
Director
Lauri Macmillan-Johnson, Associate Professor
Mary Anne Blish, Associate McLgughlin Watey' Engineers Ltd
Sick Barr^ft, Project Landscape Architect Design Workshop Inc.
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Date


URBAN DRAINAGEWATS AN AESTHETIC APPROACH TO DESIGN
by
Lin M. Takeuchi
A thesis submitted in partial fufillraent of the requirements for the degree of Master of Landscape Architecture
The University of Colorado at Denver College of Design and Planning Graduate Program Landscape Architecture
May 1986


TABLE OF CONTENTS
PREFACE ................................................. iii
ACKNOWLEDGEMENTS ........................................ vi
CHAPTER 1: INTRODUCTION ................................ 1
The need for public attention and involvement.
CHAPTER 2: DESIGN GOALS ................................ 8
A framework for design.
CHAPTER 3: AESTHETICS ................................. 14
Elements and principles of aesthetic design.
CHAPTER 4: IMAGES ..................................... 36
Aesthetics and recreation within drainageways.
CHAPTER 5: DESIGN STUDIES ............................. 53
Conceptual analyses of selected drainageways.
CHAPTER 6: DESIGN PARTICIPANTS ........................ 71
Who has influence on design and planning?
CHAPTER 7: PLANNING AND ENGINEERING ................... 87
The realities in planning and design.
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CHAPTER 8: CONTEMPORARY ISSUES ...................... 123
Past and present drainageway philosophies.
CHAPTER 9: CONCLUSIONS ............................... 133
Concluding remarks.
CHAPTER 10: GLOSSARY .................................. 138
Definitions of selected terminology.
APPENDIX ................................................ 143
A. Sites to visit
B. Site evaluation checklist
C. Recreational opportunities
D. Urban Drainage and Flood Control District
E. Agencies related to water resources
F. Plants list
G. Wildlife list
H. Natural systems
BIBLIOGRAPHY AND REFERENCES
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The sight of beautiful treatments done to streams and drainageways is very inspiring, especially in an urbanizing environment. Some are very naturalistic, and others have a distinctive urban character.
This handbook and guide was inspired by the contrast of the sight of neglected, mistreated, and insensitively designed drainageways in the fast-growing metropolitan area of Denver, Colorado.
It appeared that in most instances, opportunities for aesthetics as well as recreation could have been integrated into these waterways.
The question was how to approach this problem.
It immediately became apparent that in order to make changes, one must understand the nature of water and
PREFACE
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PREFACE
drainageways, and design criteria that is involved in making necessary improvements to channels in developing areas.
The scope of work includes with the major drainages in the Denver Metropolitan area under the jurisdiction of Urban Drainage and Flood Control District. As the subject of drainage encompasses many factors of water, the focus became open channels because of their high visibility. Therefore, selected drainageways were photographed and analyzed according to aesthetic and recreational opportunities. These drainageways were then categorized according to materials, land use, etc.
As this study progressed, one factor began to stand out as most important. The public—homeowners,
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PREFACE
developers, community leaders, etc. should be more informed as to the potential that lies within a drainageway. These people, the users and implementors, can have influence on a design, whether it be in the planning or final design stage.
This handbook attempts to make use of what designers, landscape architects, know. It offers the wonderful potentials for creative design and functional design in any type of development.
Ill



PREFACE
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A NEGLECTED AND MISTREATED AN URBANIZING ENVIRONMENT
DRAINAGEWAY
A DRAINAGEWAY WITHIN A NEW DEVELOPMENT
SENSITIVE DESIGN
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Several individuals contributed
ACKNOWLEDGEMENTS
time and effort into developing this document. In particular, I would like to thank thesis committee members for their enthusiasm for the subject matter— Mary Anne Blish, of McLaughlin Water Engineers, Ltd. in Denver, and Rick Barrett of Design Workshop, Inc. .
Urban Drainage and Flood Control District provided valuable information regarding drainageways in the metropolitan area. I am grateful for their willingness and time to discuss their philosophies and responsibilities to the public and the environment.
I would especially like to thank three special people who were always there—Jay, Carol, and Sandi.
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Stormwater flows within urban areas must be controlled to reduce or prevent damages resulting from flood events. Often times this necessitates some form of improvement to a natural stream channel or construction of a new stream channel. Creative land planning combined with engineering needs can transform this functional necessity into a recreational and aesthetic opportunity which can have a direct effect on the image of an area and its people. To fully realize this potential requires interaction between planners, designers, engineers, developers, and the people who ultimately judge the results of this communication, the users.
Every drainageway, regardless of size and importance has the potential for creation of a unique and functional amenity within any type of land use. Maximizing functional uses while improving visual quality requires the expertise of the landscape architect, the engineer, and other consultants.
Chapter 1 INTRODUCTION
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INTRODUCTION Aesthetics and drainageways
Incorporating aesthetics into drainageways is being addressed with increasing frequency, but little has been done to demonstrate in one source what these wonderful opportunities are. This document is intended to provide the reader with an overview of how the landscape architect, the engineer, the public, and other participants, can provide creative land use and enhance drainageway improvements.
Drainageway improvements Improvements, or modifications made
on a stream channel, for major drainageways within urbanizing areas are designed for the purpose of controlling flood events, stabilizing natural channels, and providing greater accessibility for maintenance activities. These modifications can be included within new developments, or
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projects that require remedial action. In many instances, satisfaction of these criteria can result in a purely functional drainageway without regard to visual and environmental impacts, recreation, or other social benefits. Physical barriers and negative visual impacts can be created and the opportunities for aesthetic and recreational amenities are lost, and its potential positive image.
A drainageway or water course has the potential to provide habitat for aquatic and terrestrial wildlife. It can also serve as a "blue-green" open space link to surrounding areas. The realities of flood hazards, sedimentation, and erosion must be also addressed.
INTRODUCTION Opportunities are lost
Potentials of drainageways
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INTRODUCTION Need for attention
Public interest is needed
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Maximizing functional uses while improving visual quality requires the expertise of the landscape architect, the engineer, and other consultants. The extent to which the design endeavor is taken is largely a factor of the owner, municipality, or developer’s concerns and available funds. But it is important to remember that the public is the ultimate client of any project. The public makes the judgements on the design by choosing to use a resource, such as a drainageway, and taking pride in it. A positive image for a place is created by continued and dedicated interest. Accomplishing this task requires not only communication between the design consultants, but communication between them and the users. Ultimately, there must be a mutual
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understanding by all parties of the philosophies and principles. This understanding can be facilitated by public presentation of the factors affecting the aesthetics and function of a drainageway.
The purpose of this study is to facilitate that communication process. Much has been written and published with regards to engineering design criteria and standards. However, it has only been in recent years that the planner and landscape architect have participated in the design process.
The intention of this handbook is to promote a general understanding of the design process and as a sourcebook for the public and design professionals for technical
INTRODUCTION
Communication
Purpose of study
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INTRODUCTION
and aesthetic elements which are used in drainageway planning.
The information presented herein is not intended to be a highly technical document for engineering design or a handbook for the public to become designers.
Several examples or case studies from the Denver Metropolitan area have been highlighted throughout the text.
Audience-the public Fundamental engineering criteria
and standards are presented, as well as basic design criteria used by landscape architects. This document addresses the public, homeowners, community leaders, neighborhood groups, and public or private developers.
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The objectives of this sourcebook are:
To encourage public awareness in drainageway improvements.
To promote creative thinking, design and planning of drainageway improvements.
To promote the image and quality of developing areas.
To take advantage of underutilized space in drainageways for use as an aesthetic or recreational amenity.
To encourage team design in drainageway improvements.
INTRODUCTION Sourcebook objectives
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"Every action begins with the identification of objectives or what is to be accomplished. While no two design projects are ever alike, each having differences of site, facilities, users, etc., there are always present in every project several goals which remains constant." (Rutledge, p. 12).
Chapter 2 DESIGN GOALS
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DESIGN GOALS Establish a framework
Identify goals
Planning and designing for a drainageway is not a simple process. For every project careful and insightful thought is taken to provide the best design for people for a particular place. Many underlying concepts can be intuitive, but these ideas must be justified for a design to fit or to be legible to a potential user. Therefore, objectives must be identified to provide a framework for all ideas, intuitive or not.
Project goals can be set within the context that the most important goals are to convey safe passage of a range of flows and provide a design creates interest and excitement and provides a variety of experiences for the user. The design for a drainageway must function in terras of stormwater
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DESIGN GOALS
conveyance, and should also address other environmental issues such as, water quality, wildlife habitat, preserving wetlands, and preventing erosion and sedimentation.
Behind any design objective there must be a reason or a purpose. One purpose is to establish a relationship between the drainageway and its surroundings to other areas within the drainageway.
Since a design is composed of many interrelatd elements, what is created in one area cannot be created in isolation because it affects other areas, aesthetically and sociologically, as well as, environmentally. Similar to principles of ecology where changes to one part of a system affects another, the elements of design have affects on each other. It is
Reason for goals
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DESIGN GOALS
up to the design team to find the best fit for a particular area.
Human values
These relationships once established, do no have significance without the user. Knowing the public's values is necessary to successful design. Designs should be "customized" according to the character of the site, its surroundings, and the needs of its users. Generic designs which contain the prescribed elements and are not responsive to the public or do not fit the site are useless. Drainageways have been designed soley to accomodate function which do not provide any sensitivity to the site or to aesthetics and recreational potential. It is no wonder many drainageways are neglected and overlooked.
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Functional requirements and user needs can and must be addressed together.
Cost and quality are other important factors to consider in a design. What is the most one can get for the lowest cost? Quality must be weighed equally with human values, cost, and function.
Without careful attention and inclusion of excellence in construction and implementation, an exciting design can be ruined. It is of no value if money was saved
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in design and construction costs, and the place is not used or enjoyed by the public.
What is aesthetically pleasing does not necessarily equate to high costs. Aesthetic considerations, ones that evoke pleasurable responses from people are
DESIGN GOALS
Cost and quality
Human value vs. cost
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DESIGN GOALS intangible benefits and difficult to assign a value.
The experience Concepts for incorporating aesthetics as well as recreation contain images for the user. By establishing a relationship between the landscape and the user in it, an emotional response or experience is created. This is created through a person's senses of sight, smell, sound, taste, and touch.
The elements and principles of aesthetics are important to recognize. The design process utilizes these elements to analyze and create experiences within a design that fits a particular site.
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Man's attraction to water's magical quality is natural and eternal. It has always been a major element in the history of man—from the fertile Nile River of Mesopotamia to the palaces and gardens of medieval and Renaissance Europe, to the contemporary uses of water today in the cities of the world.
Chapter 3 AESTHETICS
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AESTHETICS
Striking images Streams and rivers, or drainageways have the potential to become places that people love. Many have achieved that and are renown for their design and beauty. The Seine
Historic places River flows through Paris, France. It provides its users with steps and landings that lead down to the water's edge which were once used ( as boat landings in the past. These spaces are considered as recreational and scenic open space ( in the middle of a very old and large European city.
The Emerald Necklace, in Boston, < Massachusetts was designed as a park in the late 1880's along the Muddy and Charles Rivers. Today it \ is primarily admired and visited because of its connection to the central city and surrounding areas, 1 the recreation it provides, and its
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AESTHETICS
PEDESTRIANS ON AN OLD BOAT LANDING, THE SEINE RIVER
THE EMERALD NECKLACE, BOSTON MASSACHUSETTS
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AESTHETICS < naturalistic beauty within an urban area.
Contemporary places Places do not have to be very old i to have a distinguishable character. A contemporary design in San Antonio, Texas created a { riverwalk along the once neglected San Antonio River. It was reclaimed and is now a wonderful \ amenity and source of identity for the city. The design has a definite urban character with | shops, restaurants, offices, and parks very close to the water.
Islamic design-aesthetic use of water i Waterways become more precious in a semi-arid region such as Denver and its surroundings. Mediterranean < countries such as Spain, which have a climate much like ours in Denver, have for centuries used water for 1 aesthetic purposes. The most memorable features in some of the
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AESTHETICS
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AESTHETICS
Attention to water Islamic gardens are the details of tile and masonry, and most of all, the varied and beautiful uses of water. What makes these places even more special is the fact that it required very little water to achieve magical effects. Locally, drainageways should be treated with the same respect for design that the historic places of the world have had. However, one must be reminded that in most cases these designs and landscapes did not occur overnight. Much of their character is the accumulation of rich layers of growth over time. The scope or size of some of these waterways are also different but the subject remains the same. Attention should be brought to water, not so much by force and a sense of urgency, but by design


that is sensitive to people and promotes the enjoyment of the environment.
The evolving Platte River Greenway on a large scale has brought people to the river's banks and waters throughout the metropolitan area. Cherry Creek which flows into the South Platte and links to the trail system is also a popular recreational drainageway. Some of the most striking places in the are very small and can be discovered on bike rides, riding in a car, or by walking.
Harvard Gulch at McWilliams Park in South Denver has qualities of intimacy. It is a small channel in a small park, but has a naturalistic and peaceful feeling to it.
AESTHETICS
Denver images
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AESTHETICS
HARVARD GULCH AT MC WILLIAMS PARK
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Boulder Creek also is an example of a place that evokes special feelings from people in an urban setting. It contains many types of experiences for users, and is a beautiful drainageway that citizens are very proud of.
Aesthetic considerations in design have an effect on a larger area than just one short length of a drainageway. An isolated design can disrupt the overall character of a stream or river. It should be remembered that one small piece is just as important as the larger one. A drainageway is a part of a system—an environmental, functional, recreational, and aesthetic network.
In order for a drainageway to be used for enjoyment, its purpose must be clearly expressed by a
AESTHETICS
Ecological design
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Expression of design
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AESTHETICS design. That design should convey a certain character which leaves an impression on the visitor. A * strong character render a very distinguishable impression while a weak one makes no difference ^ whatsoever.
Spatial experience To understand an experience it must be labelled or named. A person must ask themselves: "What is it? How does it feel?" An experience evokes emotions that people react to. Those emotions can be positive or negative. Some of those feelings are happiness, disgust, awe, fear, and sadness. These reactions originate from stimulation of people's senses of sight, sound, touch, smell, and taste.
Enclosure Experiences of many types can be incorporated into an activity
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AESTHETICS
designated for a drainageway. Activities such as play, relaxation, and education were discussed in the previous chapter. The dominating feelings of those activities are created by different volumes of space within the drainageway—the principle of enclosure. Look at natural spaces to try to recreate these experiences. Open and free spaces allows movement in any direction. Linear spaces move in a definite direction. Finally, enclosed spaces are static and signifies lack of movement and a sense of isolation. The scale or size of enclosure creates different ranges of comfort for the user.
Spaces of enclosure are three-dimensional. This volume consists of the vertical, overhead,

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<
CHERRY CREEK AT SPEER BOULEVARD IS A LINEAR SPACE
4
LILLEY GULCH IN SOUTHWEST DENVER HAS OPEN AND FREE SPACES
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and base planes. The vertical plane consists of physical elements like channel walls, and trees and shrubs in the drainageway.
Overhead planes consist of tree branches, the sky, underpasses, etc. The earth, water, and low vegetation create the base plane. The arrangement of these elements help to make various experiences.
Within that three-dimensional space objects are either in the foreground, middleground or background. These are called distance zones. Things in the foreground are dominant and details are distinguishable. The middleground groups objects into textural masses of forms, and the background blends objects even more. Different visual effects can be consciously created in a
AESTHETICS
Distance zones
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AESTHETICS
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ROUGH TEXTURES OF ROCK

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THE SCULPTURE IS IN THE FOREGROUND THE POND IS IN THE MIDDLEGROUND THE TREES AND SHRUBS AND TREES ARE IN THE BACKGROUND
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drainageway by the placement of forms, colors, and materials within specific distance zones.
The experiences, spaces, and Visual elements
relationships within those spaces consist of basic visual elements:
Line, form, color, and texture.
These elements can be added, subtracted, or changed to enhance certain qualities in a drainageway.
Bright pink flowers add interest to an area that has predominantly non-flowering vegetation.
Zigzagging lines and rough textures can create excitement on a dull, blank channel wall. Large vertical forms provide contrast in a landscape of small horizontal objects.
Form is the shape or structure of an object. The type of material it consists of is not related to form

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in this context. It is the relationship of the object shape and its background. For example, the shape or form and size of a large boulder is different if pulled out of a channel full of water. The water provided the background and surroundings for the rock.
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In a landscape, line is the silhouette of a form. In other words, the single edges indicating directional movement. Ascending branches of a tree can lead the viewer's eye up to the overhead plane.
Color is defined as a phenomenon of light or visual perception that enables a person to distinguish between objects. The color of a certain rock in a drainageway may
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make it very unique when compared to the rest.
Texture can be either visual or tactile. It creates the surface characteristics of an object which are the distribution of lights and darks caused by differences in illumination. Leaf size and shape give texture to different forms of vegetation. Water can have texture also when flowing over different rock shapes and sizes in the channel.
Visual elements create spatial Spatial Qualities
qualities in drainageways, which in
turn create the experience. It
should be considered as a
coraposition--a work of art. The
experience creates a design and an
impact upon the viewer. These
impacts can be negative or
positive. A negative impact is one
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AESTHETICS
Visual impacts
that is displeasing to the viewer. It somehow interrupts a space in obtrusive manner. A positive impace is one that is agreeable to the landscape and to the eye. A drainageway that is neglected and full of trash has a negative impact. One that is cared for and used frequently is positive and an amenity.
Visual impacts increase or decrease in relation to the length of time it is viewed. The longer the duration the greater the impact.
The further the distance is, the lesser the impact. If a drainageway can be seen from the backyard of a home the impact to the resident will be a great significance because it will always be in close and constant view to the viewer.
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AESTHETICS
The angle of the viewer to the subject is also a consideration in visual impacts. Some drainageways are not very visible from roads or paths because their channels are deep. It is only until one is almost at the channel that it becomes visible. In other situations, a drainageway might be visible from a second story window but not from the first floor due to a deep channel or a fence.
Again, the user plays an important Th© viewer or user
part. It comes back to one of the
foremost design goals of providing
a pleasurable and memorable
experience for the user—one that
also fits into the landscape.
People have different needs and Preference
desires regarding aesthetics. The impact a view makes is dependent upon the amount of concern a person
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<
AESTHETICS
CHANNEL DESIGN AND ERODING BANKS CREATE A VISUAL IMPACT
i

THIS DRAINAGEWAY HAS A DIFFERENT VISUAL IMPACT
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VIEWER ANGLE WITHIN THE CHERRY CREEK CHANNEL
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has for a particular landscape feature—their aesthetic preferences. Everyone has a different opinion on what is beautiful. Children, teenagers, adults, the elderly, and the handicapped all have various needs and preferences. What is important to one person may hardly be significant to another. Children may love to see wetlands because it means seeing muskrats and snakes, not to mention the fun of getting muddy. An adult may not like to see such things because they dislike mosquitos, muskrats, snakes, and mud.
Aesthetics are very important in many ways to all people. The differences that arise from the individuals involved in a project are what make design a complex but
AESTHETICS
The creative process
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AESTHETICS ’
exciting process. Without
addressing aesthetics in almost any
type of design, the creative *
process and the energy that is
derived from creativity would die.
Memorable and unique places would 4
cease to exist.

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Aesthetics and recreation have a place in divergent land uses, whether a drainageway occurs in a park, residential, commercial, or industrial area. The opportunities afforded by site conditions can generate innovative and creative concepts for drainageways. The images it provides for the public can be memorable, as well as, enjoyable.
Chapter 4 IMAGES
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Creating unique images
The establishment of relationships in the drainageway is done by tying development to the place itself, the users, and functions of the site. The solution should be unique, one that fits to that particular place and distinguishes it from all others. The designer can create a place that leave lasting impressions on its users.
Concepts for design The following descriptions are
intended to serve as sketches of possible images within a drainageway. Functional aspects, such as bank stabilization and gradient or slope modification of the channel must be incorporated into the overall design aesthetics. An additional consideration for design would be the costs and quality of a variety of construction materials.
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By incorporating recreation into this environment people can begin to interact with the different aspects of the system. By providing an aesthetic element, the user will enjoy their recreational experience much more. Aesthetics and recreation cannot entirely be separated from one another.
Sitting and relaxing on a sunny porch while enjoying the view of a stream, and listening to the sounds of it flowing through one's yard is a form of recreation. It is a passive activity whereas swimming or fishing in the stream would be an active form of recreation.
IMAGES
Incorporating recreation
These examples are not necessarily singular solutions for those experiences, but are meant to prompt images for the infinite possibilities and combinations.
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IMAGES
Landscape character
Aesthetics and recreation can occur
in two types of landscape character: Urban or naturalistic.
The urban character consists of geometric and architectural forms. Hard edges are created from materials such as concrete, sculpted rock, and metal. Built forms and plant materials are more formal in arrangement than what is found in nature.
Because the floodplain has been encroached upon, many urban drainageways that are urban in character have been contained in rectangular, concrete walls. This type of channel improvement can be considered a more formal treatment to a drainageway where integration of rich detail and color can provide a significant amount of interest to an otherwise harsh


solution to drainageway improvements. An example where these opportunities were missed is the Cherry Creek drainageway along Speer Boulevard in Denver.
A naturalistic character can be created by use of softer forms. It attempts to recreate some of the informal and pastoral qualities found in nature. Therefore, native vegetation, wood, and rock are materials to integrate into a design. The Platte River Greenway is an example where these opportunities were enhanced.
Many type of activities can occur within the urban or naturalistic landscape. Each character lends itself to distinguishable or unique experiences.
IMAGES
Activities
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NATURAL VEGETATION ALONG THE SOUTH PLATTE RIVER
BOULDER CREEK IS WELL VEGETATED WITH RIPARIAN SPECIES WHICH CREATE POCKETS OF SPACE FOR EXPLORATION
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IMAGES
Adventure, exploration, and play Adventure, exploration, and play
can be incorporated by using plant and construction materials to create pockets of different spaces.
Places to climb around and through, and places to discover within the drainageway can be created through the placement of built forms and vegetation. Bright colors, bold patterns and textures lend themselves to an active, exciting environment. Otherwise, more natural tones and colors connotate a more passive environment.
Boulder Creek and the South Platte River have maintained natural riparian vegetation along their channels. This provides naturalistic spaces suitable for exploration and discovery.
Water with open and sunny areas generally attract people. Plazas
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CONFLUENCE PARK
NIGHT LIGHTING IS PROVIDED ON THE PLAZA
LITTLETON’S RIVERFRONT FESTIVAL CENTER
A PLAZA SPACE EXTENDS OUT TOWARD THE SOUTH PLATTE RIVER AT RIVER FRONT


and walks along channel banks invites interaction with the water. Mixed-use is an appropriate land use to provide people with places to shop, eat, live, and work.
These types of waterways can be very lively and colorful with the contrast of built environment and a natural feature, the water. Both day and night use can promote an active atmosphere. Use of various textures and colors in design details also provide interest and enjoyment for the user.
Confluence Park within the urban environment of Denver has a similar active character. Plazas have been constructed where the user can sit at the water’s edge. From that viewpoint or from others across the banks of Cherry Creek and the South Platte, one can watch boaters race
IMAGES
Business and park
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IMAGES
Private amenity through a kayak course. The course an example of a physical constraint (a dam) being incorporated with a unique solution for recreation. Civic activities such as concerts and running races have been held here. The design of the plaza was built to withstand flooding in addition to providing a park for citizens. Riverfront Festival Center is situated on the banks of the South Platte in Littleton. This commercial venture has a river theme that contains shops, restaurants, and a farmers' market. Space outside the buildings includes a plaza that invites users to interact with the water. Drainageways can, in some instances, be more of a private amenity for an area. In different
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sections of a city, channels traverse through various land uses with different right-of-way or easement widths. Some are so narrow that proximity to housing or any other building does not permit or public access. This is an opportunity for those people to make that drainageway a part of their office, business, or home.
Lena Gulch, which courses through a residential area west of Denver, in Wheatridge, has provided many homeowners with a "private amenity." A naturalistic channel has become more or less an integral part of the homeowners' backyards. Fences have not been erected to cut off the channel from the public.
Drainageways can also be perfect areas to provide tranquil spaces where a person can sit, relax, and
IMAGES
Relaxation
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IMAGES
LENA GULCH PROVIDES A "PRIVATE" AMENITY FOR HOMEOWNERS
A TRANQUIL SPACE ALONG BOULDER CREEK
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enjoy the scenery. The noise and sight of the movement of water which is very soothing to most people can be incorporated in the design. Soft colors and simple, flowing forms create a sense of ease and relaxation. Screening by plant materials and other materials can provide a sense of privacy for those seeking it.
Boulder Creek offers its users such spaces. Benches are provided within the drainageway, but one can also choose to sit on the large placed boulders around and in the channel. Vegetation serves as a natural screen for privacy.
Natural areas with thick riparian vegetation, such as willows and cattails, attract wildlife. This can be an educational area where people can observe waterfowl and
IMAGES
Education
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other animals. These areas do not necessarily have to occur in a
naturalistic landscape. Urban ^
settings can also provide habitat for certain species.
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Educational aspects of drainageways can be structured or unstructured in form. Structured offers a more formal setting where information is provided for people to read along paths and walks. Information can entail subjects such as natural history, environmental issues, and design and engineering considerations. Landings and walkways can be incorporated to accomodate all types of users.
Littleton's floodplain park provides adults and children with passive recreation involving nature study. The local recreation department offers programs for
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IMAGES


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people to interact with the environment and learn what a wetlands ecosystem is about. It is also an award-winning example of land reclamation of a 425-acre gravel quarry.
Endless possibilities Integration of recreation with
aesthetics creates endless possibilities for design within drainageways. Forms of recreations that can occur along waterways are listed in the appendix. Also, an awareness of the environmental and social issues creates multiple uses for this natural feature within an urbanizing context. The key, though, is to make these places memorable and unique.
Hopefully these images will evoke excitement and interest in making these places more than just useful, but also aesthetically pleasing.
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IMAGES
It is hoped, too, that other questions and ideas will result from these images.
The next chapter deals with actual design studies using existing and developed drainageways. They will exemplify situations that designers have to deal with in the course of a creating an amenity for the user.
Each example demonstrate different site opportunities and constraints, and how to develop concepts around them. The aesthetic criteria and images presented in this and the preceding chapter will be applied.
52


Design of a drainageway should never stop at resolving its functional aspects. Every effort should be made to extract any opportunity to create an amenity for people. This applies to a major drainage as well as a seemingly small and insignificant waterway.
Chapter 5 DESIGN STUDIES
53


DESIGN STUDIES
The following design studies are drainageways in the Denver that have overlooked certain opportunities for aesthetics. In one instance, function has overridden any possibility to provide an amenity. The other example provides the potential for new design to improve the function of the drainageway. Each one of them, as in all cases, have the potential to be unique, exciting, and memorable places for the public.
The two drainageways chosen are gulches and small intermittent drainages. They tend to be the most neglected of all watercourses, and because of their small scale can be used to illustrate design principles. Again, the design process must include consideration
54


DESIGN STUDIES
of function and cost as well as aesthetics and human value.
For the purposes of these studies cost will not be a constraint. It is the intent of the designs to demonstrate the full potential of a particular segment of a drainageway. A checklist for evaluation is included in the Appendix. It demonstrates methodology for analyzing the opportunities and constraints of a project site.
These examples are meant to inspire the public and other design consultants to the opportunities for aesthetics and recreation within different types of drainageways.
55


SITE LOCATION
DESIGN STUDIES Dry Gulch
Lakewood, Colorado
SURROUNDING INFLUENCES
56


SAULSBJRY ST
ROADS
ADJACENT LAND USE
VEGETATION
ENGINEERING
AESTHETICS AND RECREATION
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The design portion of Dry Gulch is located between Pierce and Saulsbury Streets which intersect with W. 10th Avenue. The drainage runs between two single-family homes and a townhouse development. The Lakewood Country Club is across W. 10th Avenue to the south. Other immediate surroundings consist primarily of an older residential neighborhood. Some newer development has occurred further downstream.
The focus will be on Dry Gulch and the townhouses that take up the majority of the site. This is an excellent example of the constraints of very narrow easements where the channel is purely functional and does not provide an amenity.
57


VIEW FROM THE PEDESTRIAN BRIDGE
THE SOLID WOOD FENCE SCREENS SOME VIEWS INTO THE CHANNEL
VIEW FROM SAULSBURY STREET
VIEW FROM PIERCE STREET
58


The existing channel is triangular and entirely concrete. The 100-year floodplain has been reduce to the confines of the channel which is 40 feet at its widest, and 7 feet deep. No other right-of-way is available due to the townhouse development and homes nearly at the edge of the channel.
No access for maintenance has been provided. Some sedimentation is evident due to the weedy vegetation established in the channel bottom. A solid wood fence separates the residents and yards for the channel. It serves to block views into the channel.
The homes are two-stories and views from upper floors cannot be screened. A solid wood pedestrian bridge crosses Dry Gulch to provide access to the other townhouses and parking. Views from the bridge into the channel are direct.
The drainage can also be seen from Pierce and Saulsbury Streets. Saulsbury Street has a very high impact due to open views down the channel. In addition, a large transmission tower exists within the right-of-way.
At Pierce Street, a naturalistic pond detracts the contrasting view of the concrete channel and the grass-banked pond. All views into the channel are negative and have the highest impact on the residents of the townhouses.
In order to carry storm flow the channel must maintain a minimum depth of 7 feet which is the existing design depth. The width must be maintained at 40 feet. Side slopes are steep at 2:1 and cannot be lessened because it would decrease depth. Therefore, they must equal the existing slope or they could become vertical walls.
There is no possibility to create a naturalistic channel because of these constraints. However, the possibility for a visually pleasing walled channel is possible.
With a walled channel, the lower flows can be contained within a narrower width. The remainder of the floodplain can be used to create more reasonable slopes of 3:1 that will be able to support grass. This will still contain the same amount of water, but will provide more usable space. The walls can be of materials such as grouted rock, stone, or cribwalls of timber to complement the architecture of the townhomes.
59


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DESIGN CONCEPTS
The new grass slopes can provide an "extension" of yardspace #
The additional space can incorporate a trail fo r maintenance and
pedestrian access. The s olid wood fence can be replace with an
open type of fence, such as a split-rail to pro vide views an d
create the effect of open "channelized" feeling. space as compared to the original
Views from the roads development. will be improved, as will the image of the
60


The alternatives to this case study were extremely restricted due to, perhaps, lack of forethought, lack of available funds, or the need or desire to construct the maximum number of units possible on a small parcel of land.
The next case study will show some of the alternatives possible in a totally different context.
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61


DESIGN STUDIES
City Park Drainage Broomfield, Colorado
62


US 2B7
City Park in Broomfield at the intersection of W. Midway Boulevard and Kohl Street is situated around the City Park Drainage. Surrounding land use consists primarily of residential housing, a school, offices, and businesses.
The existing low flow channel is approximately 1-3’ wide unstable with eroding banks. Sedimentation is occurring decreased capacity of the channel to convey lower amount runoff and stormwater efficiently. To prevent further e and increased flooding of the park, the channel bed and must be stabilized and capacity must be increased.
and is due to s of rosion banks
In this situation, the available equal to the boundaries of the pa is no need to make major changes estimated 100-year flows can be h The park serves as the drainagewa channel can be redesigned in a ve consideration not to alter the ca floodplain.
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63


I
The park can be divided into three major areas. The corner of Kohl and Midway is a highly visible area due to major auto and pedestrian traffic. This end of the park contains some mature trees that are situated close to the channel. The center section upstream has less visibility, but appears to be less active and more open due to fewer big trees. The views in this area are
long to either end of the park. The section adjacent to U.S. ^
Highway 287 is the most quiet. It is buffered with trees at the
extreme end of the park, and multi-story apartments and
single-family homes on either side. All parts of the park can be
viewed from backyards of homes to the north. The offices and
businesses face away from the park.
4
At the moment, this section of City Park offers little variety in spatial experience. The channel as it is now is almost invisible. Most of the vegetation, except for a small number of larger established trees on the low flow banks, are young, and offer little diversity.
1
The small play areas have a few pieces of equipment such as a slide, swing, merry-go-round, and jungle gyms. The park serves as a nice open, green space to the community, but has no focus.
The park as a whole provides little visual interest.
There is a considerable opportunity here, at City Park, to take I
advantage of the drainage and available right-of-way, and create more of an amenity for the city. It is, as mentioned before, a highly visible area, and can provide more activity and beauty to the surrounding homes, businesses, the park itself, and the city.
Basic concepts for park and channel development are identified on I
the program plan. Major areas within the area are highlighted.
The following chapter on planning and engineering provides information on the "realities" implementing drainageway improvements. Final plans and changes can only be made after
careful analysis of site conditions. Preliminary concepts can be ^
modified and applied with these essential considerations.
4
4
64
I


LOOKING TOWARDS KOHL AND W. MIDWAY
PEDESTRIAN CROSSING
DRAINAGE FLOWS CLOSE TO APARTMENTS
PLAY AREA AT WEST END OF PARK
65


4
4
66


WIDEN CHANNEL to increase capacity and efficiency
MEANDERS can be designed within the drainageway
ALTERNATIVE FORMS
of channel and bank stabilization



68


OPEN AREA CONCEPTS
69


70




Ideas that evolve in the development of a drainageway must be the product of a team approach. The design team must fully utilize all the opportunities a drainageway has to offer—functionally, environmentally, socially, and aesthetically.
Chapter 6
DESIGN
PARTICIPANTS
71


DESIGN PARTICIPANTS The design team
The project leader
Aesthetics in drainageways has been discussed, but no matter how beautiful a design may be it still must function. The drainageway is introduced into the landscape for specific reasons. All designs must address the safety of people and property. Some projects are of a very small scale and may not demand the involvement of several consultants. But because it addresses so many environmental and social issues, the "design team" of a larger scale drainage or major project must consist of several people.
First, the team must have a project leader who has knowledge and experience with the entire planning and design process. In the Denver area, the Urban Drainage and Flood Control District provides much of


that function. It is a raulticounty authority that manages floodplains and channel for major drainages in portions of Adams, Arapahoe,
Boulder, Denver, Douglas, and Jefferson Counties of Colorado.
The "environmental team" sets the "limits" to a drainageway improvement project. These participants are experts in their respective fields that have the ability to see the opportunities provided by the site, and to create a space that not only conveys stormwaters and prevents channel and bank erosion, but also includes recreation and aesthetics. In other words, they should attempt to incorporate multiple use to its fullest extent.
By careful analysis of site conditions, physical and
DESIGN PARTICIPANTS
The environmental team
73


DESIGN PARTICIPANTS
The landscape architect and engineer
sociological, the team decides what types of features should be maintained, eliminated, enhanced, or added. It is necessary that the team approach be used for drainageways because of the increasing environmental and social issues related to urbanizing areas.
The landscape architect and the engineer are perhaps the most important members of the team.
They should be the principle designers. The engineer has the knowledge and capability to create a functional drainageway. A complete understanding of hydraulics, the science of water and its actions through conveyance systems, and hydrology, the study of the properties of water, its distribution and circulation, make this person indispensible.


The soils engineer determines the important factors involving sedimentation and erosion. There may be constraints to design and construction in a drainageway due to soil type and conditions.
The landscape architect has expertise in the scientific, social, and artistic aspects of design. The ability to create social spaces while at the same time regarding the environment as an equally important design factor. Acquired and intuitive knowledge of aesthetics in these types of spaces is one of the most desirable traits of the profession.
Due to an increasing concern of preserving natural areas and introducing new ones to the urbanizing landscape, the ecologist and biologist are becoming very
DESIGN PARTICIPANTS
The ecologist
75


DESIGN PARTICIPANTS
important in drainageway design. Riparian vegetation and wildlife habitat are on the decline due to the encroachment of more intensive land uses. Wetlands have become an important issue recently due to the fact that they have been, and still are, disappearing at an alarming rate. Wetlands are highly value today as habitat for diverse wildlife and for contributing to higher water quality due to its filtration capabilities.
Specialists in this field will provide assistance in establishing or maintaining such areas.
Parks and recreation A specialist in parks and
recreation may be a team member. Knowledge regarding park facilities may be necessary when dealing with the installation of a park around a
76


drainageway. In some instances a parks department may be the client.
Other consultants involved may be researchers such as social scientists, anthropologists, and archaeologists. Architects may be necessary when dealing with buildings.
The South Platte River and Boulder Creek are large scale examples of full team design. Landscape architects, engineers, recreation planners, and scientists were involved in the planning of these drainages in the metropolitan area.
Smaller projects such as Lilley Gulch, Lena Gulch, and Sanderson Gulch do not require the same type of involvement as the more major drainages.
77
DESIGN PARTICIPANTS
Other consultants
Team design in Denver


DESIGN PARTICIPANTS The client
The client should be an integral part of the design team. Any person involved in the implementation of drainageway improvement is considered a client. City officials, the parks, private landowners, etc. can all be implementors of drainageways.
The developer has the opportunity to make an image for the area as well as for himself. The public involved with any drainageway is always concerned about relief from flooding problems while desiring aesthetic and recreational amenities. Being aware of the multiple uses for drainageways should be a responsibility for any developer. The need to meet floodplain requirements, park requirements, stormwater detention, landscaping requirements, as well
78


as marketing for a new development can sway decisions one makes concerning it, whether it be commercial, residential, institutional, open space, or industrial. In new development, the developer has the option to stay out of the floodplain, to fill the fringe area outside the floodway, or to construct a flood control channel to reduce the extent of the floodplain. Again, the landowner must look at the needs and wishes of potential users, who in the end, are the judges of a design.
There is an opportunity to seek out possibilities of sharing land, facilities, construction, and maintenance. The concept of multiple use has the potential of improving quality of life. This
79
DESIGN PARTICIPANTS
Multiple use


DESIGN PARTICIPANTS
DAD CLARK GULCH AT HIGHLANDS RANCH
COTTONWOOD CREEK AT INVERNESS PARK HAS BECOME PART OF A GOLF COURSE
COTTONWOOD CREEK TRIBUTARY AT RAMPART RANGE BUSINESS CENTER
80


idea is not new, but it is often ignored or overlooked.
DESIGN PARTICIPANTS
In the Denver area, Highlands Ranch is an example where the developer decided to maintain the natural 100-year floodplain as linear open space with trails throughout the development. Dad Clark Gulch is now, and will be, an amenity for residents of that and neighboring areas.
Inverness Office Park has integrated Cottonwood Creek with a golf course to support its corporate image. This golf course is a private amenity for the employees of the companies at the park. It is also highly visible from Interstate 25 as well as from within the office park.
81


DESIGN PARTICIPANTS
The user
i
i
Another example of multiple use and consideration of the users by the landowner is being constructed on a tributary of Cottonwood Creek at Rampart Business Center. The developer decided to provide an
1
amenity for users in this commercial area by incorporating trails and a system where water
I
would be recirculated in that section of the drainage to maintain perennial flow.
i
Setting a relationship between the client/developer and the user is
very important. These two members <
of the public sector can work
together. The landowner knows that
his product will be used and I
appreciated. The users know that
the landowner is concerned about
their welfare, and they have helped i
design a drainageway.
82
i
I


DESIGN PARTICIPANTS
The user is the ultimate judge of a drainageway project. They will choose to ue it or not to use it depending on the type of experience gained from it. It is, therefore, important to be aware of the issues involved in planning and designing a drainageway. Conflicts of opinion are bound to come up as a part of the process, but communication can be facilitated by knowing basic facts regarding the functions of flood control as well as basic facts in aesthetics.
Citizens can provide incentive to a Incentives for the developer
developer by suggesting ways to
help out in not only design, but in
implementation. The donation or
shared costs of plant and
construction materials, and
advertisement from individuals,
civic, neighborhood groups, and
83


DESIGN PARTICIPANTS
Citizen participation
i
corporations, etc. Volunteers can help in building the channel and
drainageway by hand-placing rock ^
and planting vegetation. Boulder Creek had exposure in local
newspapers. This generated ^
interest in the project. As a result, it has become a great source of pride for the city.
Citizen participation in designing details for walls and walks can add the personality of the users to a place. Schools might get involved in competitions or civic projects.
Areas along the South Platte display art work in the form of painted tiles on channel walls.
When the project is completed, maintenance can be done by groups like the Greenway Foundation in Denver. They provide rangers that
84


DESIGN PARTICIPANTS
patrol the park system and pick up trash and debris.
Team involvement in this manner could instill personal pride in a community, homeowners, etc.
Excitement regarding such a project would direct attention to a drainageway project. The upkeep and overall appearance of this amenity would reflect that pride.
Planning provides an invaluable framework for engineering, aesthetic, and recreational objectives. The master plan is a result of the planning process.
The next chapter describes planning as well as the functional considerations necessary for drainageway design.
85


{
DESIGN PARTICIPANTS
THE KAYAK COURSE ON THE SOUTH PLATTE RIVER AT CONFLUENCE PARK
86


Planning for a drainageway defines the opportunities and constraints within it. A master plan provides an invaluable framework for solving existing problems of a stream, and for preventing them in the future. Final design and engineering criteria can then be applied to specific sites included in the plan to create a functional and aesthetically pleasing drainageway.
Chapter 7 PLANNING AND ENGINEERING
87


PLANNING AND ENGINEERING
The master plan The master plan offers a systematic method in developing the water resources of an area, defining its flood problems, and identifying solutions to those problems. The master plan also provides analysis of benefits and costs of the suggested solutions, and a framework for the adoption and presentation of a selected plan.
A framework Because of the potential for problems upstream, and especially downstream, a design cannot be approached in a piecemeal fashion. Any modifications made on a channel will have influence on the rest of the system, good or bad.
Public involvement Public involvement can be a very complex process. Again, every individual has their own preference in aesthetics and needs. Public meetings are forums for people to
88


Full Text

PAGE 1

-Urban Drainageways: an aesthetic approach to design

PAGE 2

U18700 7486029 --

PAGE 3

THIS THESIS IS SUBMITTED AS PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR A MASTER OF LANDSCAPE ARCHITECTURE DEGREE AT THE UNIVERSITY OF COLORADO AT DENVER COLLEGE OF DESIGN AND PLANNING GRADUATE PROGRAM OF LANDSCAPE ARCHITECTURE ACCEPTED: irector Ltd. Date ARCHITECTURE & PLAN -.....,_ AURAR/A LIBRARY NING

PAGE 4

URBAN DRAINAGEWAYS AN AESTHETIC APPROACH TO DESIGN by Lin M. Takeuchi A thesis submitted in partial fufillment of the requirements for the degree of Master of Landscape Architecture The University of Colorado at Denver College of Design and Planning Graduate Program Landscape Architecture May 1986

PAGE 5

TABLE OF CONTENTS PREFACE ............................•................... iii ACKNOWLEDGEMENTS . . • . . . • . • . • . • . . . . . . . . • • . • . • . • . . . . . • • • . • vi CHAPTER 1: INTRODUCTION ........................... . 1 The need for public attention and involvement. CHAPTER 2: DESIGN GOALS ............................ 8 A framework for design. CHAPTER 3: AESTHETICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Elements and principles of aesthetic design. CHAPTER 4: IMAGES . • . . . . • • . . • . . . . . . . . . . . . . . . . . . . . . . . 36 Aesthetics and recreation within drainageways. CHAPTER 5: DESIGN STUDIES . . . . • • • . . . . . . . • • . . . . . . . . . . 53 Conceptual analyses of selected drainageways. CHAPTER 6: DESIGN PARTICIPANTS 71 Who has influence on design and planning? CHAPTER 7: PLANNING AND ENGINEERING 87 The realities in planning and design.

PAGE 6

CHAPTER 8: CONTEMPORARY ISSUES ..................... 123 Past and present drainageway philosophies. CHAPTER 9: CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Concluding remarks. CHAPTER 10: GLOSSARY 138 Definitions of selected terminology. APPENDIX 143 ( A. Sites to visit B. Site evaluation checklist C. Recreational opportunities D. Urban Drainage and Flood Control District E. Agencies related to water resources F. Plants list • G. Wildlife list H. Natural systems BIBLIOGRAPHY AND REFERENCES ............................ 160

PAGE 7

The sight of beautiful treatments done to streams and drainageways is very inspiring, especially in an urbanizing environment. Some are very naturalistic, and others have a distinctive urban character. This handbook and guide was inspired by the contrast of the sight of neglected, mistreated, and insensitively designed drainageways in the fast-growing metropolitan area of Denver, Colorado. It appeared that in most instances, opportunities for aesthetics as well as recreation could have been integrated into these waterways. The question was how to approach this problem. It immediately became apparent that in order to make changes, one must understand the nature of water and PREFACE

PAGE 8

PREFACE drainageways, and design criteria that is involved in making necessary improvements to channels in developing areas. The scope of work includes with the major drainages in the Denver Metropolitan area under the jurisdiction of Urban Drainage and Flood Control District. As the subject of drainage encompasses many factors of water, the focus became open channels because of their high visibility. Therefore, selected drainageways were photographed and analyzed according to aesthetic and recreational opportunities. These drainageways were then categorized according to materials, land use, etc. As this study progressed, one factor began to stand out as most important. The public--homeowners,

PAGE 9

developers, community leaders, etc. should be more informed as to the potential that lies within a drainageway. These people, the users and implementors, can have influence on a design, whether it be in the planning or final design stage. This handbook attempts to make use of what designers, landscape architects, know. It offers the wonderful potentials for creative design and functional design in any type of development. iil PREFACE

PAGE 10

PREFACE A NEGLECTED AND MISTREATED DRAINAGEWAY A DRAINAGEWAY WITHIN A NEW DEVELOPMENT iv AN URBANIZING ENVIRONMENT • • SENSITIVE DESIGN •

PAGE 11

Several individuals contributed time and effort into developing this document. In particular, I would like to thank thesis committee members for their enthusiasm for the subject matter-Mary Anne Blish, of McLaughlin Water Engineers, Ltd. in Denver, and Rick Barrett of Design Workshop, Inc •. Urban Drainage and Flood Control District provided valuable information regarding drainageways in the metropolitan area. I am grateful for their willingness and time to discuss their philosophies and responsibilities to the public and the environment. I would especially like to thank three special people who were always there--Jay, Carol, and Sandi. v ACKNOWLEDGEMENTS

PAGE 12

Stormwater flows within urban areas must be controlled to reduce or prevent damages resulting from flood events. Often times this necessitates some form of improvement to a natural stream channel or construction of a new stream channel. Creative land planning combined with engineering needs can transform this functional necessity into a recreational and aesthetic opportunity which can have a direct effect on the image of an area and its people. To fully realize this potential requires interaction between planners, designers, engineers, developers, and the people who ultimately judge the results of this communication, the users. Every drainageway, regardless of size and importance has the potential for creation of a unique and functional amenity within any type of land use. Maximizing functional uses while improving visual quality requires the expertise of the landscape architect, the engineer, and other consultants. 1 Chapter 1 INTRODUCTION

PAGE 13

INTRODUCTION Aesthetics and drainageways Drainageway improvements Incorporating aesthetics into drainageways is being addressed with increasing frequency, but little has been done to demonstrate in one source what these wonderful opportunities are. This document is intended to provide the reader with an overview of how the landscape architect, the engineer, the public, and other participants, can provide creative land use and enhance drainageway improvements. Improvements, or modifications made on a stream channel, for major drainageways within urbanizing areas are designed for the purpose of controlling flood events, stabilizing natural channels, and providing greater accessibility for maintenance activities. These modifications can be included within new developments, or 2 '

PAGE 14

projects that require remedial action. In many instances, satisfaction of these criteria can result in a purely functional drainageway without regard to visual and environmental impacts, recreation, or other social benefits. Physical barriers and negative visual impacts can be created and the opportunities for aesthetic and recreational amenities are lost, and its potential positive image. A drainageway or water course has the potential to provide habitat for aquatic and terrestrial wildlife. It can also serve as a "blue-green" open space link to surrounding areas. The realities of flood hazards, sedimentation, and erosion must be also addressed. 3 INTRODUCTION Opportunities are lost Potentials of drainageways

PAGE 15

INTRODUCTION Need for attention Public interest is needed Maximizing functional uses while improving visual quality requires the expertise of the landscape architect, the engineer, and other consultants. The extent to which the design endeavor is taken is largely a factor of the owner, municipality, or developer's concerns and available funds. But it is important to remember that the public is the ultimate client of any project. The public makes the judgements on the design by choosing to use a resource, such as a drainageway, and taking pride in it. A positive image for a place is created by continued and dedicated interest. Accomplishing this task requires not only communication between the design consultants, but communication between them and the users. Ultimately, there must be a mutual 4 '

PAGE 16

understanding by all parties of the philosophies and principles. This understanding can be facilitated by public presentation of the factors affecting the aesthetics and function of a drainageway. The purpose of this study is to facilitate that communication process. Much has been written and published with regards to engineering design criteria and standards. However, it has only been in recent years that the planner and landscape architect have participated in the design process. The intention of this handbook is to promote a general understanding of the design process and as a sourcebook for the public and design professionals for technical 5 INTRODUCTION Communication Purpose of study

PAGE 17

INTRODUCTION Audience-the public and aesthetic elements which are used in drainageway planning. The information presented herein is not intended to be a highly technical document for engineering design or a handbook for the public to become designers. Several examples or case studies from the Denver Metropolitan area have been highlighted throughout the text. Fundamental engineering criteria and standards are presented, as well as basic design criteria used by landscape architects. This document addresses the public, homeowners, community leaders, neighborhood groups, and public or private developers. 6

PAGE 18

The objectives of this sourcebook are: To encourage public awareness in drainageway improvements. To promote creative thinking, design and planning of drainageway improvements. To promote the image and quality of developing areas. To take advantage of underutilized space in drainageways for use as an aesthetic or recreational amenity. To encourage team design in drainageway improvements. 7 INTRODUCTION Sourcebook objectives

PAGE 19

"Every action begins with the identification of objectives or what is to be accomplished. While no two design projects are ever alike, each having differences of site, facilities, users, etc., there are always present in every project several goals which remains constant." (Rutledge, p. 12). 8 Chapter 2 DESIGN GOALS

PAGE 20

DESIGN GOALS Establish a framework Identify goals Planning and designing for a drainageway is not a simple process. For every project careful and insightful thought is taken to provide the best design for people for a particular place. Many underlying concepts can be intuitive, but these ideas must be justified for a design to fit or to be legible to a potential user. Therefore, objectives must be identified to provide a framework for all ideas, intuitive or not. Project goals can be set within the context that the most important goals are to convey safe passage of a range of flows and provide a design creates interest and excitement and provides a variety of experiences for the user. The design for a drainageway must function in terms of stormwater 9

PAGE 21

DESIGN GOALS conveyance, and should also address other environmental issues such as, water quality, wildlife habitat, preserving wetlands, and preventing erosion and sedimentation. Behind any design objective there Reason for goals must be a reason or a purpose. One purpose is to establish a relationship between the drainageway and its surroundings to other areas within the drainageway. Since a design is composed of many interrelatd elements, what is created in one area cannot be created in isolation because it affects other areas, aesthetically and sociologically, as well as, environmentally. Similar to principles of ecology where changes to one part of a system affects another, the elements of design have affects on each other. It is 10

PAGE 22

DESIGN GOALS Human values up to the design team to find the best fit for a particular area. These relationships once established, do no have significance without the user. Knowing the public's values is necessary to successful design. Designs should be "customized" according to the character of the site, its surroundings, and the needs of its users. Generic designs which contain the prescribed elements and are not responsive to the public or do not fit the site are useless. Drainageways have been designed soley to accomodate function which do not provide any sensitivity to the site or to aesthetics and recreational potential. It is no wonder many drainageways are neglected and overlooked. 11

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Functional requirements and user needs can and must be addressed together. Cost and quality are other important factors to consider in a design. What is the most one can get for the lowest cost? Quality must be weighed equally with human values, cost, and function. Without careful attention and inclusion of excellence in construction and implementation, an exciting design can be ruined. It is of no value if money was saved in design and construction costs, and the place is not used or enjoyed by the public. What is aesthetically pleasing does not necessarily equate to high costs. Aesthetic considerations, ones that evoke pleasurable responses from people are 12 DESIGN GOALS Cost and quality Human value vs. cost

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DESIGN GOALS The experience intangible benefits and difficult to assign a value. Concepts for incorporating aesthetics as well as recreation contain images for the user. By establishing a relationship between the landscape and the user in it, an emotional response or experience is created. This is created through a person's senses of sight, smell, sound, taste, and touch. The elements and principles of aesthetics are important to recognize. The design process utilizes these elements to analyze and create experiences within a design that fits a particular site. 13

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Man's attraction to water's magical quality is natural and eternal. It has always been a major element in the history of man--from the fertile Nile River of Mesopotamia to the palaces and gardens of medieval and Renaissance Europe, to the contemporary uses of water today in the cities of the world. 14 Chapter 3 AESTHETICS

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AESTHETICS Striking images Historic places Streams and rivers, or drainageways have the potential to become places that people love. Many have achieved that and are renown for their design and beauty. The Seine River flows through Paris, France. It provides its users with steps and landings that lead down to the water's edge which were once used as boat landings in the past. These spaces are considered as recreational and scenic open space in the middle of a very old and large European city. The Emerald Necklace, in Boston, Massachusetts was designed as a park in the late 1880's along the Muddy and Charles Rivers. Today it is primarily admired and visited because of its connection to the central city and surrounding areas, the recreation it provides, and its 15

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AESTHETICS PEDESTRIANS ON AN OLD BOAT LANDING, THE SEINE RIVER THE EMERAL NECKLACE, BOSTON MASSACHUSETTS. 16

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AESTHETICS Contemporary places Islamic design-aesthetic use of water naturalistic beauty within an urban area. Places do not have to be very old to have a distinguishable character. A contemporary design in San Antonio, Texas created a riverwalk along the once neglected San Antonio River. It was reclaimed and is now a wonderful amenity and source of identity for the city. The design has a definite urban character with shops, restaurants, offices, and parks very close to the water. Waterways become more precious in a semi-arid region such as Denver and its surroundings. Mediterranean • countries such as Spain, which have a climate much like ours in Denver, have for centuries used water for • aesthetic purposes. The most memorable features in some of the 17

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THE SAN ANTONIO RIVERWALK ISLAMIC DESIGN AT THE COURT OF LIONS AT THE ALHAMBRA IN SPAIN 18 AESTHETICS

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AESTHETICS Attention to water Islamic gardens are the details of tile and masonry, and most of all, the varied and beautiful uses of water. What makes these places even more special is the fact that it required very little water to achieve magical effects. Locally, drainageways should be treated with the same respect for design that the historic places of the world have had. However, one must be reminded that in most cases these designs and landscapes did not occur overnight. Much of their character is the accumulation of rich layers of growth over time. The scope or size of some of these waterways are also different but the subject remains the same. Attention should be brought to water, not so much by force and a sense of urgency, but by design 19 •

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that is sensitive to people and promotes the enjoyment of the environment. The evolving Platte River Greenway on a large scale has brought people to the river's banks and waters throughout the metropolitan area. Cherry Creek which flows into the South Platte and links to the trail system is also a popular recreational drainageway. Some of the most striking places in the are very small and can be discovered on bike rides, riding in a car, or by walking. Harvard Gulch at McWilliams Park in South Denver has qualities of intimacy. It is a small channel in a small park, but has a naturalistic and peaceful feeling to it. 20 AESTHETICS Denver images

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AESTHETICS HARVARD GULCH AT MC WILLIAMS PARK CHILDREN'S FISHING POOL AT BOULDER CREEK 21

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AESTHETICS Boulder Creek also is an example of a place that evokes special feelings from people in an urban setting. It contains many types of experiences for users, and is a beautiful drainageway that citizens are very proud of. Aesthetic considerations in design Ecological design have an effect on a larger area than just one short length of a drainageway. An isolated design can disrupt the overall character of a stream or river. It should be remembered that one small piece is just as important as the larger one. A drainageway is a part of a system--an environmental, functional, recreational, and aesthetic network. In order for a drainageway to be Expres-sion of design used for enjoyment, its purpose must be clearly expressed by a 22

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AESTHETICS Spatial experience Enclosure design. That design should convey a certain character which leaves an impression on the visitor. A strong character render a very distinguishable impression while a weak one makes no difference whatsoever. To understand an experience it must be labelled or named. A person must ask themselves: "What is it? How does it feel?" An experience evokes emotions that people react to. Those emotions can be positive or negative. Some of those feelings are happiness, disgust, awe, fear, and sadness. These reactions originate from stimulation of people's senses of sight, sound, touch, smell, and taste. Experiences of many types can be incorporated into an activity 23

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AESTHETICS designated for a drainageway. Activities such as play, relaxation, and education were discussed in the previous chapter. The dominating feelings of those activities are created by different volumes of space within the drainageway--the principle of enclosure. Look at natural spaces to try to recreate these experiences. Open and free spaces allows movement in any direction. Linear spaces move in a definite direction. Finally, enclosed spaces are static and signifies lack of movement and a sense of isolation. The scale or size of enclosure creates different ranges of comfort for the user. Spaces of enclosure are three-dimensional. This volume consists of the vertical, overhead, 24

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AESTHETICS CHERRY CREEK AT SPEER BOULEVARD IS A LINEAR SPACE LILLEY GULCH IN SOUTHWEST DENVER HAS OPEN AND FREE SPACES 25 A BRIDGE AT CHERR Y CREEK CREATES AN ENCLOSED SPACE

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and base planes. The vertical plane consists of physical elements like channel walls, and trees and shrubs in the drainageway. Overhead planes consist of tree branches, the sky, underpasses, etc. The earth, water, and low vegetation create the base plane. The arrangement of these elements help to make various experiences. Within that three-dimensional space objects are either in the foreground, middleground or background. These are called distance zones. Things in the foreground are dominant and details are distinguishable. The middleground groups objects into textural masses of forms, and the background blends objects even more. Different visual effects can be consciously created in a 26 AESTHETICS Distance zones

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AESTHETICS TRICKLE CHANNEL AND WIRES ARE LINES THE BUILDINGS AND TREE ARE FORM ROUGH TEXTURES OF ROCK THE SCULPTURE IS IN THE FOREGROUND THE POND IS IN THE MIDDLEGROUND THE TREES AND SHRUBS AND TREES ARE IN THE BACKGROUN D 27 ( C

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drainageway by the placement of forms, colors, and materials within specific distance zones. The experiences, spaces, and relationships within those spaces consist of basic visual elements: Line, form, color, and texture. These elements can be added, subtracted, or changed to enhance certain qualities in a drainageway. Bright pink flowers add interest to an area that has predominantly non-flowering vegetation. Zigzagging lines and rough textures can create excitement on a dull, blank channel wall. Large vertical forms provide contrast in a landscape of small horizontal objects. Form is the shape or structure of an object. The type of material it consists of is not related to form 28 AESTHETICS Visual elements

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AESTHETICS in this context. It is the relationship of the object shape and its background. For example, the shape or form and size of a large boulder is different if pulled out of a channel full of water. The water provided the background and surroundings for the rock. In a landscape, line is the silhouette of a form. In other words, the single edges indicating directional movement. Ascending branches of a tree can lead the viewer's eye up to the overhead plane. Color is defined as a phenomenon of light or visual perception that enables a person to distinguish between objects. The color of a certain rock in a drainageway may 29 I

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make it very unique when compared to the rest. Texture can be either visual or tactile. It creates the surface characteristics of an object which are the distribution of lights and darks caused by differences in illumination. Leaf size and shape give texture to different forms of vegetation. Water can have texture also when flowing over different rock shapes and sizes in the channel. Visual elements create spatial qualities in drainageways, which in turn create the experience. It should be considered as a composition--a work of art. The experience creates a design and an impact upon the viewer. These impacts can be negative or positive. A negative impact is one 30 AESTHETICS Spatial qualities

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AESTHETICS Visual impacts that is displeasing to the viewer. It somehow interrupts a space in obtrusive manner. A positive impace is one that is agreeable to the landscape and to the eye. A drainageway that is neglected and full of trash has a negative impact. One that is cared for and used frequently is positive and an amenity. Visual impacts increase or decrease in relation to the length of time it is viewed. The longer the duration the greater the impact. The further the distance is, the lesser the impact. If a drainageway can be seen from the backyard of a home the impact to the resident will be a great significance because it will always be in close and constant view to the viewer. 31 • •

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The angle of the viewer to the subject is also a consideration in visual impacts. Some drainageways are not very visible from roads or paths because their channels are deep. It is only until one is almost at the channel that it becomes visible. In other situations, a drainageway might be visible from a second story window but not from the first floor due to a deep channel or a fence. Again, the user plays an important part. It comes back to one of the foremost design goals of providing a pleasurable and memorable experience for the user--one that also fits into the landscape. People have different needs and desires regarding aesthetics. The impact a view makes is dependent upon the amount of concern a person 32 AESTHETICS The viewer or user Preference

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AESTHETICS VIEWER ANGLE WITHIN THE CHERRY CREEK CHANNEL CHANNEL DESIGN AND ERODING BANKS CREATE A VISUAL IMPACT THIS DRAINAGEWAY HAS A DIFFERENT < J VISUAL IMPACT t 33 I

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has for a particular landscape feature--their aesthetic preferences. Everyone has a different opinion on what is beautiful. Children, teenagers, adults, the elderly, and the handicapped all have various needs and preferences. What is important to one person may hardly be significant to another. Children may love to see wetlands because it means seeing muskrats and snakes, not to mention the fun of getting muddy. An adult may not like to see such things because they dislike mosquitos, muskrats, snakes, and mud. Aesthetics are very important in many ways to all people. The differences that arise from the individuals involved in a project are what make design a complex but 34 AESTHETICS The creative process

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AESTHETICS exciting process. Without addressing aesthetics in almost any type of design, the creative process and the energy that is derived from creativity would die. Memorable and unique places would cease to exist. 35 I <.l •

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Aesthetics and recreation have a place in divergent land uses, whether a drainageway occurs in a park, residential, commercial, or industrial area. The opportunities afforded by site conditions can generate innovative and creative concepts for drainageways. The images it provides for the public can be memorable, as well as, enjoyable. 36 Chapter 4 IMAGES

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IMAGES Creating unique images Concepts for design The establishment of relationships in the drainageway is done by tying development to the place itself, the users, and functions of the site. The solution should be unique, one that fits to that particular place and distinguishes it from all others. The designer can create a place that leave lasting impressions on its users. The following descriptions are intended to serve as sketches of possible images within a drainageway. Functional aspects, such as bank stabilization and gradient or slope modification of the channel must be incorporated into the overall design aesthetics. An additional consideration for design would be the costs and quality of a variety of construction materials. 37

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By incorporating recreation into this environment people can begin to interact with the different aspects of the system. By providing an aesthetic element, the user will enjoy their recreational experience much more. Aesthetics and recreation cannot entirely be separated from one another. Sitting and relaxing on a sunny porch while enjoying the view of a stream, and listening to the sounds of it flowing through one's yard is a form of recreation. It is a passive activity whereas swimming or fishing in the stream would be an active form of recreation. These examples are not necessarily singular solutions for those experiences, but are meant to prompt images for the infinite possibilities and combinations. 38 IMAGES Incorporating recreation

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IMAGES Landscape character Aesthetics and recreation can occur in two types of landscape character: Urban or naturalistic. The urban character consists of geometric and architectural forms. Hard edges are created from materials such as concrete, sculpted rock, and metal. Built forms and plant materials are more formal in arrangement than what is found in nature. Because the floodplain has been encroached upon, many urban drainageways that are urban in character have been contained in rectangular, concrete walls. This type of channel improvement can be considered a more formal treatment to a drainageway where integration of rich detail and color can provide a significant amount of interest to an otherwise harsh 39 •

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solution to drainageway improvements. An example where these opportunities were missed is the Cherry Creek drainageway along Speer Boulevard in Denver. A naturalistic character can be created by use of softer forms. It attempts to recreate some of the informal and pastoral qualities found in nature. Therefore, native vegetation, wood, and rock are materials to integrate into a design. The Platte River Greenway is an example where these opportunities were enhanced. Many type of activities can occur within the urban or naturalistic landscape. Each character lends itself to distinguishable or unique experiences. 40 IMAGES Activities

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IMAGES NATURAL VEGETATION ALONG THE SOUTH PLATTE RIVER BOULDER CREEK IS WELL VEGETATED WITH RIPARIAN SPECIES WHICH CREATE POCKETS OF SPACE FOR EXPLORATION 41

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Adventure, exploration, and play can be incorporated by using plant and construction materials to create pockets of different spaces. Places to climb around and through, and places to discover within the drainageway can be created through the placement of built forms and vegetation. Bright colors, bold patterns and textures lend themselves to an active, exciting environment. Otherwise, more natural tones and colors connotate a more passive environment. Boulder Creek and the South Platte River have maintained natural riparian vegetation along their channels. This provides naturalistic spaces suitable for exploration and discovery. Water with open and sunny areas generally attract people. Plazas 42 IMAGES Adventure, exploration, and play

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IMAGES CONFLUENCE PARK LITTLETON'S RIVERFRONT FESTIVAL CENTER NIGHT LIGHTING IS PROVIDED ON THE PLAZA A PLAZA SPACE EXTENDS OUT TOWARD THE SOUTH PLATTE RIVER AT RIVER FRONT 43

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and walks along channel banks invites interaction with the water. Mixed-use is an appropriate land use to provide people with places to shop, eat, live, and work. These types of waterways can be very lively and colorful with the contrast of built environment and a natural feature, the water. Both day and night use can promote an active atmosphere. Use of various textures and colors in design details also provide interest and enjoyment for the user. Confluence Park within the urban environment of Denver has a similar active character. Plazas have been constructed where the user can sit at the water's edge. From that viewpoint or from others across the banks of Cherry Creek and the South Platte, one can watch boaters race 44 IMAGES Business and park

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IMAGES Private amenity through a kayak course. The course an example of a physical constraint (a dam) being incorporated with a unique solution for recreation. Civic activities such as concerts and running races have been held here. The design of the plaza was built to withstand flooding in addition to providing a park for citizens. Riverfront Festival Center is situated on the banks of the South Platte in Littleton. This commercial venture has a river theme that contains shops, restaurants, and a farmers' market. Space outside the buildings includes a plaza that invites users to interact with the water. Drainageways can, in some instances, be more of a private amenity for an area. In different 45

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sections of a city, channels traverse through various land uses with different right-of-way or easement widths. Some are so narrow that proximity to housing or any other building does not permit or public access. This is an opportunity for those people to make that drainageway a part of their office, business, or home. Lena Gulch, which courses through a residential area west of Denver, in Wheatridge, has provided many homeowners with a "private amenity." A naturalistic channel has become more or less an integral part of the homeowners' backyards. Fences have not been erected to cut off the channel from the public. Drainageways can also be perfect areas to provide tranquil spaces where a person can sit, relax, and 46 IMAGES Relaxation

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IMAGES LENA GULCH PROVIDES A "PRIVATE" AMENITY FOR HOMEOWNERS A TRANQUIL SPACE ALONG BOULDER CREEK 47

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enjoy the scenery. The noise and sight of the movement of water which is very soothing to most people can be incorporated in the design. Soft colors and simple, flowing forms create a sense of ease and relaxation. Screening by plant materials and other materials can provide a sense of privacy for those seeking it. Boulder Creek offers its users such spaces. Benches are provided within the drainageway, but one can also choose to sit on the large placed boulders around and in the channel. Vegetation serves as a natural screen for privacy. Natural areas with thick riparian vegetation, such as willows and cattails, attract wildlife. This can be an educational area where people can observe waterfowl and 48 IMAGES Education

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IMAGES other animals. These areas do not necessarily have to occur in a naturalistic landscape. Urban settings can also provide habitat for certain species. Educational aspects of drainageways can be structured or unstructured in form. Structured offers a more formal setting where information is provided for people to read along paths and walks. Information can entail subjects such as natural history, environmental issues, and design and engineering considerations. Landings and walkways can be incorporated to accomodate all types of users. Littleton's floodplain park provides adults and children with passive recreation involving nature study. The local recreation department offers programs for 49

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so IMAGES SOUTH PLATTE PARK CONTAINED WITHIN THE 100-YEAR FLOODPLAIN

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IMAGES Endless possibilities people to interact with the environment and learn what a wetlands ecosystem is about. It is also an award-winning example of land reclamation of a 425-acre gravel quarry. Integration of recreation with aesthetics creates endless possibilities for design within drainageways. Forms of recreations that can occur along waterways are listed in the appendix. Also, an awareness of the environmental and social issues creates multiple uses for this natural feature within an urbanizing context. The key, though, is to make these places memorable and unique. Hopefully these images will evoke excitement and interest in making these places more than just useful, but also aesthetically pleasing. 51

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It is hoped, too, that other questions and ideas will result from these images. The next chapter deals with actual design studies using existing and developed drainageways. They will exemplify situations that designers have to deal with in the course of a creating an amenity for the user. Each example demonstrate different site opportunities and constraints, and how to develop concepts around them. The aesthetic criteria and images presented in this and the preceding chapter will be applied. 52 IMAGES

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Design of a drainageway should never stop at resolving its functional aspects. Every effort should be made to extract any opportunity to create an amenity for people. This applies to a major drainage as well as a seemingly small and insignificant waterway. 53 Chapter 5 DESIGN STUDIES

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DESIGN STUDIES The following design studies are drainageways in the Denver that have overlooked certain opportunities for aesthetics. In one instance, function has overridden any possibility to provide an amenity. The other example provides the potential for new design to improve the function of the drainageway. Each one of them, as in all cases, have the potential to be unique, exciting, and memorable places for the public. The two drainageways chosen are gulches and small intermittent drainages. They tend to be the most neglected of all watercourses, and because of their small scale can be used to illustrate design principles. Again, the design process must include consideration 54

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of function and cost as well as aesthetics and human value. For the purposes of these studies cost will not be a constraint. It is the intent of the designs to demonstrate the full potential of a particular segment of a drainageway. A checklist for evaluation is included in the Appendix. It demonstrates methodology for analyzing the opportunities and constraints of a project site. These examples are meant to inspire the public and other design consultants to the opportunities for aesthetics and recreation within different types of drainageways. 55 DESIGN STUDIES

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W. 101M AVE. W91MA\IE. SITE LOCATION "' Ill 0 W llf'HPL DESIGN STUDIES Dry Gulch Lakewood, Colorado SURROUNDING INFLUENCES 56

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ROADS StQE-fAMLY tOES ADJACENT l..AI'D USE VEGETATKJN ENGINEERING AESTl-TlCS AND RECREATION e ,.,.......,te f"&,Of)"" • ..-ND Wlfli 2: I Cf 11'WN The design portion of Dry Gulch is located between Pierce and Saulsbury Streets which intersect with W. lOth Avenue. The drainage runs between two single-family homes and a townhouse development. The Lakewood Country Club is across W. lOth Avenue to the south. Other immediate surroundings consist primarily of an older residential neighborhood. Some newer development has occurred further downstream. The focus will be on Dry Gulch and the townhouses that take up the majority of the site. This is an excellent example of the constraints of very narrow easements where the channel is purely functional and does not provide an amenity. 57

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VIEW FROM THE PEDESTRIAN BRIDGE VIEW FROM SAULSBURY STREET 58 THE SOLID WOOD FENCE SCREENS SOME VIEWS INTO THE CHANNEL VIEW FROM PIERCE STREET

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The existing channel is triangular and entirely concrete. The 100-year floodplain has been reduce to the confines of the channel which is 40 feet at its widest, and 7 feet deep. No other right-of-way is available due to the townhouse development and homes nearly at the edge of the channel. No access for maintenance has been provided. Some sedimentation is evident due to the weedy vegetation established in the channel bottom. A solid wood fence separates the residents and yards for the channel. It serves to block views into the channel. The homes are two-stories and views from upper floors cannot be screened. A solid wood pedestrian bridge crosses Dry Gulch to provide access to the other townhouses and parking. Views from the bridge into the channel are direct. The drainage can also be seen from Pierce and Saulsbury Streets. Saulsbury Street has a very high impact due to open views down the channel. In addition, a large transmission tower exists within the right-of-way. At Pierce Street, a naturalistic pond detracts the contrasting view of the concrete channel and the grass-banked pond. All views into the channel are negative and have the highest impact on the residents of the townhouses. In order to carry storm flow the channel must maintain a minimum depth of 7 feet which is the existing design depth. The width must be maintained at 40 feet. Side slopes are steep at 2:1 and cannot be lessened because it would decrease depth. Therefore, they must equal the existing slope or they could become vertical walls. There is no possibility to create a naturalistic channel because of these constraints. However, the possibility for a visually pleasing walled channel is possible. With a walled channel, the lower flows can be contained within a narrower width. The remainder of the floodplain can be used to create more reasonable slopes of 3:1 that will be able to support grass. This will still contain the same amount of water, but will provide more usable space. The walls can be of materials such as grouted rock, stone, or cribwalls of timber to complement the architecture of the townhomes. 59

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Q-WHL • PM'6 MT't 'JD QfoMII&.. • loi4DIIfT ,... tillS w:IIG DESIGN CONCEPTS OWH3.. .,... ,.,.__.,.,..., . 'lllii.IU),.,.. -l.f I'I'D1 !A. /'f ., I 11' !:RIC "f" • IJIIOoiUI tJiff'<8 ,.. IN ,._ IC9f!E!D pt!Ra I I..,: .. The new grass slopes can provide an "extension" of yardspace. The additional space can incorporate a trail for maintenance and pedestrian access. The solid wood fence can be replace with an open type of fence, such as a split-rail to provide views and create the effect of open space as compared to the original "channelized" feeling. Views from the roads will be improved, as will the image of the development. 60

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The alternatives to this case study were extremely restricted due to, perhaps, lack of forethought, lack of available funds, or the need or desire to construct the maximum number of units possible on a small parcel of land. The next case study will show some of the alternatives possible in a totally different context. J l • "{(eW ! =NEW CHANNEL CONCEPTS +---4o-:-:-. 0J0aJ_ ---) N (-------f"tijf f_ fC..tJ.W . DEVELOPMENT CONCEPTS 61 EXISTING RELATIONSHIPS

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SITE LOCATION 62 DESIGN STUDIES City Park Drainage Broomfield, Colorado 0 ---L/

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SITE CONDITIONS VEGETATON __ ,.__,. _T ....... O'II'
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The park can be divided into three major areas. The corner of Kohl and Midway is a highly visible area due to major auto and pedestrian traffic. This end of the park contains some mature trees that are situated close to the channel. The center section upstream has less visibility, but appears to be less active and more open due to fewer big trees. The views in this area are long to either end of the park. The section adjacent to U.S. Highway 287 is the most quiet. It is buffered with trees at the extreme end of the park, and multi-story apartments and single-family homes on either side. All parts of the park can be viewed from backyards of homes to the north. The offices and businesses face away from the park. At the moment, this section of City Park offers little variety in spatial experience. The channel as it is now is almost invisible. Most of the vegetation, except for a small number of larger established trees on the low flow banks, are young, and offer little diversity. The small play areas have a few pieces of equipment such as a slide, swing, merry-go-round, and jungle gyms. The park serves as a nice open, green space to the community, but has no focus. The park as a whole provides little visual interest. There is a considerable opportunity here, at City Park, to take advantage of the drainage and available right-of-way, and create more of an amenity for the city. It is, as mentioned before, a highly visible area, and can provide more activity and beauty to the surrounding homes, businesses, the park itself, and the city. Basic concepts for park and channel development are identified on the program plan. Major areas within the area are highlighted. The following chapter on planning and engineering provides information on the "realities" implementing drainageway improvements. Final plans and changes can only be made after careful analysis of site conditions. Preliminary concepts can be modified and applied with these essential considerations. 64 t

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LOOKING TOWARDS KOHL AND W. MI WAY PEDESTRIAN CROSSING ERODING BANKS DRAINAGE FLOWS CLOSE TO APARTMENTS PLAY AREA AT WEST END OF PARK 65

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• .-I ...... DESIGN CONCEPTS a-tANE..----' fll.AY l'i'EA • _,.,..-66 CU. VERT 4

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-t .. __ :t __ ALTERNATIVE FORMS of channel and bank stabilization 67 WIDEN CHANNEL to increase capacity and efficiency MEANDERS can be designed within the drainageway

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}6 fM21 df f'()c'r W tilt 1Z? w.A0e 68 HIGH VISIBILITY AREA CONCEPTS

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69 OPEN AREA CONCEPTS

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t 70 QUIET AREA CONCEPTS

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Ideas that evolve in the development of a drainageway must be the product of a team approach. The design team must fully utilize all the opportunities a drainageway has to offer--functionally, environmentally, socially, and aesthetically. 71 Chapter 6 DESIGN PARTICIPANTS

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DESIGN PARTICIPANTS The design team The project leader Aesthetics in drainageways has been discussed, but no matter how beautiful a design may be it still must function. The drainageway is introduced into the landscape for specific reasons. All designs must address the safety of people and property. Some projects are of a very small scale and may not demand the involvement of several consultants. But because it addresses so many environmental and social issues, the "design team" of a larger scale drainage or major project must consist of several people. First, the team must have a project leader who has knowledge and experience with the entire planning and design process. In the Denver area, the Urban Drainage and Flood Control District provides much of 72 4 •

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that function. It is a multicounty authority that manages floodplains and channel for major drainages in portions of Adams, Arapahoe, Boulder, Denver, Douglas, and Jefferson Counties of Colorado. The "environmental team" sets the "limits" to a drainageway improvement project. These participants are experts in their respective fields that have the ability to see the opportunities provided by the site, and to create a space that not only conveys stormwaters and prevents channel and bank erosion, but also includes recreation and aesthetics. In other words, they should attempt to incorporate multiple use to its fullest extent. By careful analysis of site conditions, physical and 73 DESIGN PARTICIPANTS The environmental team

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DESIGN PARTICIPANTS The landscape architect and engineer sociological, the team decides what types of features should be maintained, eliminated, enhanced, or added. It is necessary that the team approach be used for drainageways because of the increasing environmental and social issues related to urbanizing areas. The landscape architect and the engineer are perhaps the most important members of the team. They should be the principle designers. The engineer has the knowledge and capability to create a functional drainageway. A complete understanding of hydraulics, the science of water and its actions through conveyance systems, and hydrology, the study of the properties of water, its distribution and circulation, make this person indispensible. t 74

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The soils engineer determines the important factors involving sedimentation and erosion. There may be constraints to design and construction in a drainageway due to soil type and conditions. The landscape architect has expertise in the scientific, social, and artistic aspects of design. The ability to create social spaces while at the same time regarding the environment as an equally important design factor. Acquired and intuitive knowledge of aesthetics in these types of spaces is one of the most desirable traits of the profession. Due to an increasing concern of preserving natural areas and introducing new ones to the urbanizing landscape, the ecologist and biologist are becoming very 75 DESIGN PARTICIPANTS The ecologist

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DESIGN PARTICIPANTS Parks and recreation important in drainageway design. Riparian vegetation and wildlife habitat are on the decline due to the encroachment of more intensive land uses. Wetlands have become an important issue recently due to the fact that they have been, and still are, disappearing at an alarming rate. Wetlands are highly value today as habitat for diverse wildlife and for contributing to higher water quality due to its filtration capabilities. Specialists in this field will provide assistance in establishing or maintaining such areas. A specialist in parks and recreation may be a team member. Knowledge regarding park facilities may be necessary when dealing with the installation of a park around a 76

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drainageway. In some instances a parks department may be the client. Other consultants involved may be researchers such as social scientists, anthropologists, and archaeologists. Architects may be necessary when dealing with buildings. The South Platte River and Boulder Creek are large scale examples of full team design. Landscape architects, engineers, recreation planners, and scientists were involved in the planning of these drainages in the metropolitan area. Smaller projects such as Lilley Gulch, Lena Gulch, and Sanderson Gulch do not require the same type of involvement as the more major drainages. 77 DESIGN PARTICIPANTS Other consultants Team design in Denver

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DESIGN PARTICIPANTS The client The client should be an integral part of the design team. Any person involved in the implementation of drainageway improvement is considered a client. City officials, the parks, private landowners, etc. can all be implementors of drainageways. The developer has the opportunity to make an image for the area as well as for himself. The public involved with any drainageway is always concerned about relief from flooding problems while desiring aesthetic and recreational amenities. Being aware of the multiple uses for drainageways should be a responsibility for any developer. The need to meet floodplain requirements, park requirements, stormwater detention, landscaping requirements, as well 78

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as marketing for a new development can sway decisions one makes concerning it, whether it be commercial, residential, institutional, open space, or industrial. In new development, the developer has the option to stay out of the floodplain, to fill the fringe area outside the floodway, or to construct a flood control channel to reduce the extent of the floodplain. Again, the landowner must look at the needs and wishes of potential users, who in the end, are the judges of a design. There is an opportunity to seek out possibilities of sharing land, facilities, construction, and maintenance. The concept of multiple use has the potential of improving quality of life. This 79 DESIGN PARTICIPANTS Multiple use

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DESIGN PARTICIPANTS DAD CLARK GULCH AT HIGHLANDS RANCH COTTONWOOD CREEK AT INVERNESS PARK HAS BECOME PART OF A GOLF COURSE 80 COTTONWOOD CREEK TRIBUTARY AT RAMPART RANGE BUSINESS CENTER

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idea is not new, but it is often ignored or overlooked. In the Denver area, Highlands Ranch is an example where the developer decided to maintain the natural 100-year floodplain as linear open space with trails throughout the development. Dad Clark Gulch is now, and will be, an amenity for residents of that and neighboring areas. Inverness Office Park has integrated Cottonwood Creek with a golf course to support its corporate image. This golf course is a private amenity for the employees of the companies at the park. It is also highly visible from Interstate 25 as well as from within the office park. 81 DESIGN PARTICIPANTS

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DESIGN PARTICIPANTS The user Another example of multiple use and consideration of the users by the landowner is being constructed on a tributary of Cottonwood Creek at Rampart Business Center. The developer decided to provide an amenity for users in this commercial area by incorporating trails and a system where water would be recirculated in that section of the drainage to maintain perennial flow. Setting a relationship between the client/developer and the user is very important. These two members of the public sector can work together. The landowner knows that his product will be used and appreciated. The users know that the landowner is concerned about their welfare, and they have helped design a drainageway. 82 t

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The user is the ultimate judge of a drainageway project. They will choose to ue it or not to use it depending on the type of experience gained from it. It is, therefore, important to be aware of the issues involved in planning and designing a drainageway. Conflicts of opinion are bound to come up as a part of the process, but communication can be facilitated by knowing basic facts regarding the functions of flood control as well as basic facts in aesthetics. Citizens can provide incentive to a developer by suggesting ways to help out in not only design, but in implementation. The donation or shared costs of plant and construction materials, and advertisement from individuals, civic, neighborhood groups, and 83 DESIGN PARTICIPANTS Incentives for the developer

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DESIGN PARTICIPANTS Citizen participation corporations, etc. Volunteers can help in building the channel and drainageway by hand-placing rock and planting vegetation. Boulder Creek had exposure in local newspapers. This generated interest in the project. As a result, it has become a great source of pride for the city. Citizen participation in designing details for walls and walks can add the personality of the users to a place. Schools might get involved in competitions or civic projects. Areas along the South Platte display art work in the form of painted tiles on channel walls. When the project is completed, maintenance can be done by groups like the Greenway Foundation in Denver. They provide rangers that 84 4

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patrol the park system and pick up trash and debris. Team involvement in this manner could instill personal pride in a community, homeowners, etc. Excitement regarding such a project would direct attention to a drainageway project. The upkeep and overall appearance of this amenity would reflect that pride. Planning provides an invaluable framework for engineering, aesthetic, and recreational objectives. The master plan is a result of the planning process. The next chapter describes planning as well as the functional considerations necessary for drainageway design. 85 DESIGN PARTICIPANTS

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DESIGN PARTICIPANTS THE KAYAK COURSE ON THE SOUTH PLATTE RIVER AT CONFLUENCE PARK STEPS DOWN TO BOULDER CREEK 86

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.. Planning for a drainageway defines the opportunities and constraints within it. A master plan provides an invaluable framework for solving existing problems of a stream, and for preventing them in the future. Final design and engineering criteria can then be applied to specific sites included in the plan to create a functional and aesthetically pleasing drainageway • 87 Chapter 7 PLANNING AND ENGINEERING

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PLANNING AND ENGINEERING The master plan A framework Public involvement The master plan offers a systematic method in developing the water resources of an area, defining its flood problems, and identifying solutions to those problems. The master plan also provides analysis of benefits and costs of the suggested solutions, and a framework for the adoption and presentation of a selected plan. Because of the potential for problems upstream, and especially downstream, a design cannot be approached in a piecemeal fashion. Any modifications made on a channel will have influence on the rest of the system, good or bad. Public involvement can be a very complex process. Again, every individual has their own preference in aesthetics and needs. Public meetings are forums for people to 88

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express those opinions. But this is also the time and place for public awareness to grow and create excitement over a resource such as a drainageway. Establishing the environmental team, involving the client, and the public, along with political leaders is critical to any design. Social, environmental, and functional opportunities and constraints are determined by investigation of the physical environment, policies, and social patterns of the people. Citizens can voice their opinions as to what they want for recreation and aesthetics. Historic artifacts and other special attributes of a drainageway can be preserved as a result of first-hand knowledge of the area. 89 PLANNING AND ENGINEERING Establish the design team

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PLANNING AND ENGINEERING Develop alternative approaches From that point the team can begin to develop alternative approaches to planning and design of the drainageway by determining the available right-of-way. The right-of-way is a factor of flow requirements for conveyance of stormwater. The client or the landowner can also help in determining the width of the easement by considering the possibility of multiple use and aesthetic amenity for the user. As discussed in a previous chapter, the Greenway Foundation contributed additional funds to money provided by Urban Drainage and Flood Control District and the City of Denver to acquire additional right-of-way for Weir Gulch. It permitted the construction of a grass channel with a trail instead of the proposed concrete channel. 90

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Human values and aesthetics, function, and cost are weighed in the planning stage. Even though all of these factors should be considered with the first and second as most important, cost is usually the biggest determining factor in selecting a plan. As mentioned in Chapter 6, "Design Participants," the developer can investigate the possibility of shared costs for multiple use. Preliminary designs present those alternatives and assigns benefits and costs to channel modifications and development of the drainageway, including recreation and aesthetics. Design concepts shown to the public and client should be demonstrated visually through graphic presentation. Seeing the design and intended relationships 91 PLANNING AND ENGINEERING The weighing of values Preliminary design

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PLANNING AND ENGINEERING Final design Engineering criteria to other areas has the potential to eliminate problems of what was perceived in the plans after implementation. The final design then consists of refinement of the selected alternative, the function, aesthetics, human values, and costs of a drainageway. Bank treatments for stabilization, trails for maintenance and recreation, landscaping, in other words, what the channel and drainageway will look like, is determined at this stage. Much of the design is determined by the analysis of the engineering criteria. Criteria for channels and drainageways is a factor of the characteristics created by the flow of water through them. The definitions in this chapter are 92

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taken from the Urban Storm Drainage Criteria Manual for Denver. In the metropolitan area, the largest drainage is the South Platte River. All other drainages in this region eventually flow into the Platte. Some of these are designated as creeks, and others, gulches. The drainages carry water the entire year or are perennial, such as the South Platte or Cherry Creek. Others are intermittent streams which are dry for periods of time. Even though the gulches may seem harmless due to their size and "dry" nature, they have the potential to carry significant flow during and after storms. These drainages are also the most neglected and mistreated of the streams. 93 PLANNING AND ENGINEERING Drainages

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PLANNING AND ENGINEERING 1 00-year floodplain ••ooo N&Z&•o ...... -----l t---,.., •• ., ,. .. Ptel• ,..., •• .._, .. ,, It is important to recognize the components of a drainageway. The floodplain or flood hazard area is defined by the level of the 100-year flood, and therefore, is the largest element of a drainageway. The 100-year floodplain provides the basis for any drainageway design. In natural conditions, it conveys the 100-year flood which might be expected to be equalled or exceeded once in 100 years on the average, over a long period of time. Development, for safety and environmental reasons, must be kept of out this area. The floodplain can be modified to confine flows through a narrower course, but this constriction sacrifices the potential for providing an amenity. 94

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The floodway is a portion of the floodplain that is required for the reasonable passage or conveyance of the design flood, which might be lesser than the 100-year flood. The channel includes the stream bed and banks that confine periodic or continuous flows of water. Small low-flow concrete channels, sometimes referred to as trickle channels, are necessary to confine normal flows into a protected area to prevent excessive erosion to the stream bed. Due to the effects of urbanization, improvements or modifications must be made to channels to stabilize banks and prevent erosion. Increasing the conveyance capacity of the drainageway to reduce velocities is necessary to minimize erosion. 95 PLANNING AND ENGINEERING The floodway The channel Effects of urbanization

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PLANNING AND ENGINEERING Channel design I I The choice of channel design, alignment, shape, and construction materials takes into consideration its hydraulics, or how the water moves through it. This includes and is related to the thalweg, or the lowest thread along the axial part of a valley, and its slope or steepness. Each drainageway has a certain capacity for passing different ranges of flow through a site. The amount of available right-of-way or width for a drainageway is then dictated by flow requirements for the conveyance of stormwater and also the existing conditions of around it, such as land use. A design also considers basin sediment yield or channel stability which indicates the amount of erosion occuring in and around the channel. 96

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I As always, there are other influencing factors to consider in a design. Costs of construction and maintenance may prohibit the use of some materials and surface treatments such as gabions, which can be difficult to maintain, or rock walls, which can be expensive to construct. Preservation of natural features such as wetlands, vandalism, policies, street and traffic patterns as well as public preference must be analyzed. Final design criteria are critical in minimizing the erosional capabilities of the existing flow. It allows stabilization of the proposed channel design with the inclusion of other uses such as recreation. Any type of material used in channel design has a designated 97 PLANNING AND ENGINEERING Final design criteria Roughness

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PLANNING AND ENGINEERING roughness coefficient or value. In other words, the smoother the material, the faster the flow because there is less friction. Therefore, the coefficient is lower. Velocity and roughness are directly related. Velocity The design or permissible velocity is the highest velocity at which water may be carried through a channel without excessive damage. For example, grass channels should be designed for a maximum of 7 feet per second. Grass is only capable of withstanding slower flows due to its lower resistance to erosion. Depth The design depth recognizes the scour potential of the channel material. The greater the depth water has the more power it has to create erosion, and therefore, sedimentation problems downstream. 98

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Channel side slopes, critical or design slopes, must be of a specific percentage in order to function well. Erosion and stablility is a factor of the steepness of slope. For example, a gradual slope of 4:1 is recommended for maintenance of grass channel channels. Rock slopes, if grouted, can be designed at a ratio of 2:1. Curvature of the should not be sharp in order for the channel to function properly. Again, erosion is the major consideration as well as capacity for water does not naturally make sudden turns. Flood capacity and freeboard relates to the vertical distance between the normal maximum level of the water surface within a 99 PLANNING AND ENGINEERING Side slopes Curvature Flood capacity

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PLANNING AND ENGINEERING Backwater effects drainageway and the highest elevation of that course. This elevation varies depending on conditions. Generally, 1-2' greater than the 100-year flood level is sufficient. Freeboard is provided so that the water will not overtop the drainageway and bridges spanning them. Bridges and culverts create backwater effects in the drainageway. These structures constrict water, particularly from accumulation of debris, by altering the characteristics of flow. Velocities slow down at these points and tend to create flooding problems if not taken into consideration. One can see this effect at auto and pedestrian crossings after a heavy rainstorm. 100

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PLANNING AND ENGINEERING BRIDGE WITH SMALL CULVERT AT SANDERSON GULCH ANOTHER BRIDGE FARTHER DOWNSTREAM WITH A DIFFERENT DESIGN 1-----101

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PLANNING AND ENGINEERING Channel geometry Channel realignment Energy dissipaters Channel shape or cross sectional geometry also has an effect on water flows. The more water that touches the surface of the channel, the more friction occurs. The more friction, the slower the velocity. Channel geometry can be rectangular, parabolic, triangular, or trapezoidal. At one time channel realignment was widely practiced. This action straightens or changes the course of a drainage. It drastically alters the stability of channel and has resulted in many problems downstream due to increased velocities and high construction costs. Needless to say, realignment or straightening of a channel is not recommended. Structures in the channel are sometimes necessary to decrease the 102

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PLANNING AND ENGINEERING A RECTANGULAR CHANNEL A TRAPEZOIDAL CHANNEL A TRIANGULAR CHANNEL 103

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PLANNING AND ENGINEERING energy created by faster flows. These are called energy dissipaters and can be used to permit pools or more placid water for functional as well as aesthetic purposes. Goldsmith Gulch has utilized energy dissipaters as a part of recreation. These structures are meant to double as seating for users when the drainage is not carrying stormwater. Drop structures Drop structures are a form of energy dissipater and gradient modification. They are designed to reduce the effective channel slope, and therefore, the velocity of flow. In nature, waterfalls and cascades provide gradient or slope ; changes. Drop structures act in the same manner as stairs for steep slopes in built spaces. 104

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PLANNING AND ENGINEERING CHERRY CREEK GOLDSMITH GULCH DROP STRUCTURES LITTLE DRY CREEK 105

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PLANNING AND ENGINEERING RIVERFRONT FESTIVAL CENTER WEIR GULCH DRAINAGE IN BOULDER DROP STRUCTURES HARVARD GULCH 106

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There are many other solutions to preventing bank and channel erosion. Under natural conditions banks and channels become stabilized over the course of time. Final design criteria tries to duplicate natural conditions for urbanizing areas which upset the natural balance of a stream. Banks are naturally stabilized by the interaction of rock, soil, and vegetation. Roots of plants bind soil substrate together and prevent the wearing away of that material. Channel beds adjust to the average annual flows that continually, but slowly, shape them. There are various methods a designer can choose from to prevent erosion which attempt to follow the same principles of nature. Each of those methods has the potential to 107 PLANNING AND ENGINEERING Bank stabilization

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PLANNING AND ENGINEERING Grass be aesthetically pleasing depending upon the design and visual aspects of the material--line, form, color, and texture. Much of the quality of design relies upon the execution or implementation of the design and its details. Costs are always an influencing design consideration and vary with the material used as well as cost of construction and maintenance. Grass is widely used in the Denver Metropolitan area. A wide variety of native drought resistant grass mixtures can create beautiful and low maintenance drainageways. However, bluegrass which must be irrigated, is more suitable for areas designated for intensive recreation. Polypropolene netting is used on sections of Cherry Creek at Speer Boulevard to hold banks in 108

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PLANNING AND ENGINEERING BANK EROSION AT LILLEY GULCH GRASS BANKS AT SANDERSON GULCH 109

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PLANNING AND ENGINEERING Rock place to prevent water erosion before the sod has a chance to become established. Interlocking concrete pieces that, again, help prevent erosion before seeded vegetation becomes established, have also been used along Cherry Creek. Grass drainageways and channels, if not cared for, can begin to look neglected and worn. Again,use of native grasses are encourage because of their resistance to drought and require less mowing. Also popular is the use of rock, which is highly resistant to erosion. Riprap can be carefully hand-placed, or it can be dumped. Grouted riprap that is held by a cementing mixture can maintain steeper slopes of 2:1. Rock comes 110

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PLANNING AND ENGINEERING TRI-LOCK INTERLOCKING FORMS AT CHERRY CREEK COMBINATION OF WOOD AND RIPRAP AT LENA GULCH 1 1 1

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PLANNING AND ENGINEERING in many forms, sizes, and colors. However, rock size depends on the velocity or stream flow. If they are too small, the water will move them downstream. Hand-placed boulders along and in a channel can look very naturalistic. However, if not large enough, there may be a problem with people taking them to use for their yards. Also, if rock masses are used for banks that are of an unsuitable, unnatural color, the effect be very harsh. Grouted riprap has a tendency have the look of massive amounts of concrete with a few rocks mixed in. If done with care, however, this method can have the appearance of the loose rock. Rock is available in the form of gabions. These are basically wire baskets containing stones. They 112 •

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D CONCRETE LOW FLOW AT LILLEY GULCH PLANNING AND ENGINEERING GROUTED.ROCK AT RIVERFRONT FESTIVAL CENTER ANOTHER FORM OF GROUTED ROCK 113

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PLANNING AND ENGINEERING Concrete are installed either as drop structures or bank and channel stabilizers. If desired! gabions have the potential to have the establishment of vegetation cover them. They have a naturalistic appearance and can be very attractive in some situations. However, they are generally not recommended due to vandalism and high maintenance. Wire baskets tend to break, or are cut to remove the stones. Concrete is perhaps the most unnatural-looking of all the materials, but it is very resistant to higher velocities. It also prevents the establishment of unwanted vegetation. Concrete can be very drab and stark, but various textures and details can be added 114 •

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GAB IONS A COMBINATION OF CONCRETE, GRASS, AND GROUTED ROCK 115 PLANNING AND ENGINEERING

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PLANNING AND ENGINEERING Wood Natural vegetation to wall surfaces. Color can also be mixed into its mixture. The use of wood in creating walls and terraced banks make it a very attractive alternative to concrete. However, timber, if exposed to both wet and dry conditions, will rot and require replacement in the future. They are long-lasting if kept continuously wet or dry by a consisent water surface. Mcintyre Gulch at Meadowlark Park in Lakewood has used timber for bank stabilization. A method for stabilization is to maintain natural or existing vegetation. It not only preserves a well established bank, it helps improve water quality and wildlife habitat. Plants can provide a filtration system for pollutants as well as preventing erosion and 116

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PLANNING AND ENGINEERING A TIMBER WALL ON MC INTYRE GULCH AT MEADOWLARK PARK NATURAL VEGETATION AT SOUTH PLATTE PARK 117

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PLANNING AND ENGINEERING Soil bioengineering sedimentation. In order to maintain wildlife, cover and food must be provided. Riparian and aquatic vegetation contains the food and shelter for many species of animals. Soil bioengineering is similar to utilizing existing vegetation. It uses specific native plant materials for actually building the main structural component of the bank. An example of a very old technique called "twilling and wattling" will be used in the Denver area along sections of the South Platte River and Cherry Creek. This method uses live willow stakes and branches to provide structural stability while the plant roots have a chance to establish themselves. The result will eventually be a very 118

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PLANNING AND ENGINEERING Implementation structurally stable and very natural looking channel. Other methods integrate structural components such as cribwork to stabilize banks while vegetation becomes established. Cribwork involves the use of live or treated timbers to build the bank. Live vegetation, gravel, and soil are used to fill it. Consideration of the availability and quality of special plant material at the time of implementation is very important. Obtaining native riparian vegetation from construction sites can also be used. Any of these construction and stabilization methods can be combined if desired. The visual relationship between them must be studied as well as the structural 119

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integrity and function. Other things to consider are ease of installation, the availability of materials, and, of course, the cost. If it is a new type of installation, the designer must be sure to be specific about details. Quality assurance should always be a factor because execution of a design can make or break it. Dewatering or the diversion of water during construction must be considered also. Careful design implementation will not matter if proper care is not taken to maintain a drainageway. Grass can look patchy and be full of weeds. Channels tend to collect debris from upstream and surrounding areas. Urban Drainage and Flood Control District provides 120 PLANNING AND ENGINEERING Maintenance

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PLANNING AND ENGINEERING a maintenance program that includes regular and scheduled mowings. Mowing stimulates grass growth and helps control weeds and rodents in developed areas. Vegetation along South Platte Park in Littleton does not require mowings due to its natural environment. Rodents and other wildlife are appropriate and desired here. Removing trash prevents flooding due to constricted channels and culverts. Old tires, shopping carts, dead trees, discarded couches, and dryers are often found dumped into streams. Debris and trash like this contribute to the negative visual impacts and general environment of a drainageway, as well as the surrounding neighborhood. 121

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A functioning and aesthetic drainageway can be an object of pride for the public that uses them for enjoyment. The better a drainageway looks and the more visible it is, the better care is taken by the users to maintain its character. 122 PLANNING AND ENGINEERING

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In recent time, the magical qualities of water were lost or hidden by insensitive design in drainageways. The tradition of the wonderful and rich waterways of the past was lost due to the rapid growth of cities and their suburbs. Much of what was done with these recent designs have had direct effects on the image of a neighborhood, park, city, or region, and its people. As a result, there has been a revival of interest and need for creative design incorporating the increasing demand for aesthetics and recreation, as well as, economy and function. 123 Chapter 8 CONTEMPORARY ISSUES

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Changes in attitude Recent philosophies There is still much evidence left of old and sensitive philosophies used in drainageway design--the Emerald Necklace in Boston, and the Seine River in Paris, France. However, since that time alternative solutions have been created which reflect only the consideration of function and economy. In recent time, prior to present day philosophies, drainageway planning and design consisted of extensive modification of channels. Much of this is in evidence today. Floodplains were narrowed due to the encroachment of development. With some exceptions, channels were straightened and the waters were kept from structures and buildings by using levees and concrete channels. Aesthetics and 124

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recreation were not integrated into the designs. In fact, the drainageway was not considered as a visual or recreational amenity. If it was a large enough body of water it was used as a tool for transportation and sewage. Preserving wildlife and riparian vegetation was not considered as a priority and thousands of acres of wetlands were destroyed in order to make way for development. People once regarded wetlands as frightening places, sources of disease, and waste land. Thus, these areas were treated as useless nuisances that were only valuable if drained and developed upon. There were, and still are, repercussions of such philosophies. Intensive land development within the 100-year floodplain has led to 125 CONTEMPORARY ISSUES Destruction of natural environment Repercussions of the past

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CONTEMPORARY ISSUES extensive flooding in areas such as the Mississippi River Valley even though levees were built to control the flow and distribution of the water. Confinement of the river raises its level considerably and decreases its capacity to hold increased flows. Breaks in the levees and other flood control devices can and have created disastrous effects to development within the floodplain destroying lives and property. Unsightly flood control channels in other areas have permenantly altered the state of many drainageways. Southern California has straightened and confined many drainages, like the Los Angeles River, to huge concrete channels. There is nothing natural about them except the water. Sections of 126 •

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CONTEMPORARY ISSUES FLOODPROOFING AT THE BOULDER JUSTICE CENTER FLOOD CONTROL CHANNEL AT WEIR GULCH 127

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CONTEMPORARY ISSUES New philosophies Harvard and Weir Gulches in Denver have used the same approach but on much smaller scale. These examples exist everywhere. Some can be remedied, and others cannot. These mistakes have been costly, in terms of economics and social benefits. Fortunately, innovative and sensitive thinking has changed many of the old attitudes towards flood control and treatment of drainageways. Many lessons have been learned from past examples of continual flood damage, problems with sedimentation and erosion, as well as aesthetics. With increasing competition of development, the image of a project is becoming very important. Planners and engineers have been forced to change their methods and 128 •

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CONTEMPORARY ISSUES philosophies with the need to incorporate those factors. The first priority in planning for Maintain natural channel a drainageway is to attempt to maintain natural channels and natural channel configuration. Any channel realignment is kept to a minimum and is done as a last resort. There no longer is an attempt to keep the water away from development and people. Instead development is planned to respect the 100-year floodplain. The concept of multiple use is being employed into these areas. Floodplains are being reserved for flood detention, open space, and recreation corridors. Non-structural approaches to flood Non-structural approaches control and bank stabilization have been used and are proving to be functionally and cost effective. 129

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CONTEMPORARY ISSUES Creative planning concepts Environmentally and aesthetically, it is the best alternative. Wildlife habitat can be preserved or introduced, as well as maintaining or introducing valuable riparian vegetation. Creative planning concepts in urbanizing areas, particularly in residential planning, emphasize the integration of open space with flood protection in drainageways. With the concept of cluster housing and planned subdivisions, natural configuration and vegetation of the stream channel may be maintained fullfilling the increasing demands for open space and recreation. Streets parallel to waterways is one concept that includes preservation of the drainageway environment. Homes face the stream from across the street turning 130

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CONTEMPORARY ISSUES their attention to it instead of away from it. Maintenance is easier due to increased accessibilty. Vandalism decreases and safety increases as well because of increased visibility. Design of looping roads and cul-de-sacs are variations of the parallel street. Each of these concepts provide access by reaching to the drainageway. Studies have proven that these planned community street patterns , ___ , j-1 II I -1 I I -. 1support the incorporation of drainageways and open space. When compared to a typical subdivision design any losses in the calculated number of homes were not significant, and in some cases, there were gains in dwelling units per acre. Total development costs were less for the newer designs and 131

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CONTEMPORARY ISSUES the value of the amenity provided would offset any loss of developable land. A number of communities in Santa Clara County, California, as well as other locations in the United States, have been able to preserve many streams as riparian and open space corridors while providing flood protection. 132 • '

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"In relatively humid and well-vegetated parts of the country, such as most of the United States east of the Mississippi, and in mountainous areas generally, the stable streams in their natural condition were clear and attractive, with shade, fish in the deeper water, and an irregular alternation of rapids, riffles, and pools which most people find agreeable. Some of the western areas were less pleasant, where natural alkali, parched and arid soils, treeless plains, burnt over vegetation, and dry stream beds struck a harsher note; but even then many of the small streams had a narrow valley of bushes and small trees to shade and help to stabilize the channnel. It is important to keep in mind this original state of small streams, because it is important to have environmental quality and provide amenities when we can. The fact that the natural beauty of an unspoiled stream cannot be reduced to a mathematical formula is no excuse for ignoring it." (Tucker, p. 124). 133 Chapter 9 CONCLUSIONS

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Drainageways, today, are being planned and designed with the increasing need for open space within urbanizing areas. However, these are usually in newer developments that are beginning to realize that a small stream that part of the time is merely a trickle can be a wonderful amenity to the public. In many instances, though, the drainage is secondary to the space around it. Open space is planned, but it sometimes becomes a large grassy area with a pedestrian path with no diversity or visual interest. In older developments, channels of previous designs are still evident. Many of them, because of increased development upstream and age, are in need of improvements or rehabilitation. No matter how 134 1

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small the right-of-way there, the potential still exists for aesthetic and original design. The public involved, though, needs to be informed of these possibilities. They should also understand the basics of the design process in order to begin to appreciate this often "hidden" amenity resource. In reality, cost is always a factor, but with the attention to, and appreciation of, drainageways it is hoped that more cooperation will be given to improvements. As demonstrated, rivers, streams and, in fewer instances, gulches, can be designed with aesthetics in mind. Also, aesthetics can be incorporated with function, and recreation as well. Team design, when appropriate, is extremely important. The landscape 135 CONCLUSIONS

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architect is becoming more and more necessary in drainageway design due to their artistic and environmental education and training. The engineer who has the knowledge of hydraulics and hydrology must design the functional aspect of a drainageway. But together, as a team, they can combine their talents, along with other consultants, and with the needs of the public, have the to enhance the design process to its fullest extent. This combined creativity can, and will, promote the image and quality of life of developing areas. It is hoped that this handbook will provoke public interest and creative design in drainageways. 136

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137

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Because drainageway improvements and designs require the expertise of many different professions, oftentimes some terminology is not familiar to all participants. This glossary has been provided to aid in understanding technical terms. 138 Chapter 10 GLOSSARY

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Backwater -The water retarded above a dam or backed up into a tributary by a flood in the main stream. Channel -A natural or artificial watercourse of perceptible extent which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water. It has a definite bed and banks which serve to confine the water. Drainageway -A route or course along which water moves or may move to drain an area. Drop -A vertical structure in a conduit or canal installed for the purpose of dropping water to a lower level. Erosion -Wearing away of the lands by running water and waves, abrasion and transportation. Flood-Water from a river, stream, watercourse,, ocean, lake, or other body of water that temporarily overflows or inundates adjacent lands and which may effect otherlands and activities through stage elevation, backwater and/or increased groundwater level. Design Flood -The amount of runoff for which the major project features are sized. It may be the largest flood considered probable, or the largest flood which it is economically feasible to control. Flood Control -The by the construction improvements, dikes engineering works. alternative. elimination or reduction of flood losses of flood storage reservoirs, channel and levees, by-pass channels, or other Sometimes called the structural Floodplain -The relatively flat or lowland area adjoining a river, stream, watercourse, ocean, lake, or other body of standing water which has been or may be covered temporarily by flood water. Floodplain Management -Control of use of land subject to flooding. Floodplain Fringe -That portion of the floodplain that lies outside the regulatory area. Its hazard should be 139

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recognized although it is not great enough to make public regulations desirable. Floodway -Floodway is that portion of the regulatory area required for the reasonable passage or conveyance of the design flood. This is the area of significant depths and velocities and due consideration should be given to effects of fill, loss of cross sectional flow area, and resulting increased water surface elevations. Freeboard -The vertical distance between the normal maximum level of the surface of the liquid in a conduit, reservoir, tank, basin, canal, etc., and the top of the confining structure, which is provided so that waves and other movements of the liquid will not overtop such confining structures. Gabion -A wire basket containing earth or stones, deposited with others to provide protection against erosion. Grade -The inclination or slope of a channel, canal, conduit, etc., or natural ground surface, usually expressed in terms of the percentage of number of units of vertical rise (or fall) per unit of horizontal distance. Hydraulics -A branch of science that deals with practical applications of the mechanics of water movement. Hydrology -The science that deals with the processes governing the depletion and replenishment of the water resources of the land areas of the earth. Impervious -A term applied to material through which water cannot pass, or through water passes with great difficulty. Infiltration -The absorption of liquid water by the sil, either as it falls as precipitation, or from a stream flowing overthe surface. Lining -Impervious material such as concrete, clay, grass, plastic, puddled earth,, etc., placed on the sides and bottom of a ditch, channel, and reservoir to prevent or reduce seepage of water through the sides and bottom and/or to prevent erosion. 140

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Major Drainage System -That storm drainage system which carries the runoff from a storm having a frequency of occurrence of once in 100 years. The major system will function whether or not it has been planned and designed, and whether or no improvements are situated wisely in respect to it. The major system usually includes many features such as streets, gulches, and major drainage channels. The good planning and designing of a major system should eliminated major damages and loss of life from storms having a one percent chance of occurring in any given year. Multiple Use -The concept of providing relief from flooding problems while also providing more amenities such as recreation facilities. 100-Year Flood Size of flood which might be expected to be equalled or exceeded once in 100 years on the average, over a long period of time (with given conditions). 100-Year Storm Size of storm equalled or exceeded on the average once in 100 years. Regulatory Area -That portion of the floodplain subject to inundation by the 100-year flood is defined as the regulatory area. Its width is determined by the 100-year flood. Its length or reach is determined by natural bounds such as an ocean or lake, or by structure such as a dam or bridge, or by political or legal bounds. In the absence of complete nformation to define or estimate a 100-year flood, an interim regulatory area may be designated on the basis of satisfactory existing floodplain information. Riprap -Broken stone or boulders placed compactly or irregularly on dams, levees, ditches, dikes, etc., for protection of earth surfaces against the erosive action of water. Runoff -That part of the precipitation which reaches a stream, drain, sewer, etc., directly or indirectly. Sediment -Material of soil and rock origin transported, carried, or deposited by water. 141

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Sociological Impact -Results of an event or situation which affects the behavior or attitudes of a group of people. Stilling Basin -A pool of water conventionally used, as part of a drop structure or other structure, to dissipate energy. Stream -A body of flowing water. The term is usually applied to a body of water flowing in a natural surface channel, but is also applied to a body of water flowing in a well-defined, open or closed conduit, a jet of water issuing from any opening, such as a nozzle, a fissure in rock, etc. Stream Erosion -Also called channel erosion or degradation. The tendency of a stream to dig its channel deeper by erosion. Thalweg -The lowest thread along the axial part of a valley Trickle Channel -A small channel located within the major channel. Its purpose is to confine thenormal base flows and runoff from minor rainfall events to a small protected area. Velocity -A time rate of change of position. Watercourse -A channel in which a flow of water occurs, either continuously or intermittently, and if the latter, with some degree of regularity. Such flow must be in a definite direction. Watercourses may be either natural or artificial, and the former may occur either on the surface or underground. Also known as drainageway and waterway. 142

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APPENDIX 143

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SITES TO VISIT LENA GULCH in Wheatridge -32nd and Vivian Private amenity, public participation, naturalistic design LENA GULCH in Golden -Orchard Road and Colfax Avenue Private amenity, public participation, use of extensive use of riprap and some timber walls COTTONWOOD GULCH in Southeast Denver -Inverness Office Park Office park and golf course LILLEY GULCH in Littleton -Maplewood and Field Retention of wetlands with rehabilitation of channel LITTLE DRY CREEK in Westminster -80th and Estes Residential development (more recent) with integrated open space DRY GULCH in Lakewood -W. lOth Avenue and Pierce Street Concrete channel in narrow right-of-way WEIR GULCH in Denver -1st Avenue and Quitman Street Concrete flood control channel WEIR GULCH in Denver -Bayaud and South Weir Drive Linear park in residential neighborhood where houses face the drainageway SANDERSON GULCH in Denver -W. Colorado Avenue and Java Part of the Greenway System BOULDER CREEK in Boulder Naturalistic treatment of a major drainage and team design GOLDSMITH GULCH in Southeast Denver S. Union and Belleview Multiple use and creative, urban design SOUTH PLATTE RIVER in Denver The Greenway, Confluence Park, South Platte Park, team design DAD CLARK GULCH at Highlands Ranch Incorporation of trails and recreation in the drainageway throughout the development 144

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CHERRY CREEK in Denver Speer Boulevard Walled channel with trail, several methods of bank stabilization LITTLE DRY CREEK in Englewood -Dartmouth and Santa Fe Drive Unusual energy dissipator, partially walled channel MC INTYRE GULCH in Lakewood -3rd Avenue and Meadowlark Timber wall in neighborhood park. TRIBUTARY OF COTTONWOOD CREEK in Southeast Denver South Arapahoe Road Drainageway is under construction, but will be a special water feature RIVERFRONT FESTIVAL CENTER in Littleton Santa Fe and Littleton Boulevard 145

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SITE EVALUATION CHECKLIST The following list is intended to be a basic checklist for evaluating a drainageway. This can be expanded or condensed according to each situation. It relates directly to the design considerations addressed in the text and provides a methodology for analysis. DRAINAGEWAY LOCATION: City and streets SURROUNDING INFLUENCES: Adjacent land uses-office/commercial, residential, industrial, mixed-use, institutional, park, roads SITE CONDITIONS: Auto and pedestrian paths, relationships of areas to other areas within the drainageway, how structures relate to other structures and uses within the drainageway, natural elements ENVIRONMENT AND ECOLOGY: The occurrence of erosion and sedimentation, appearance or lack of wildlife-terrestrial and aquatic-birds, fish, mammals, and reptiles, natural riparian vegetation, planted species AESTHETICS: Types of views, the occurrence of views and visual impacts, landscape character, visual elements, focal points,, diversity and interest, existing and potential recreational opportunities, materials used to design the channel and implementation PLANNING AND ENGINEERING: Extent of floodplain or available right-of-way, channel and bank stability, use of appropriate construction materials, channel geometry, final engineering design criteria!, type of drainage-perennial or intermittent, multiple use MAINTENANCE AND ACCESS The existence of trails for maintenance vehicles, doubles as recreational trail 146

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RECREATIONAL OPPORTUNITIES Recreation can be in an structured and unstructured form. This means that one may be in a space designed for a specific function, like playing basketball or baseball. On the other hand, one may desire to use a place that allows a choice in activity such as reading or throwing a frisbee. Recreation can also be categorized as active or passive. Active recreation involves sports such as baseball, volleyball, fishing, boating, and cross-country skiing. Hiking, viewing scenery, wildlife observation, and picnicking are considered passive. ACTIVE Fishing -Improvements can be made on urbanizing streams where fish habitat can be integrated or restored Boating -The South Platte has incorporated kayak courses into its channel as a part of its plans for improvements. Other forms of boating can also take place. Swimming -Higher water quality is necessary for this type of activity due to possible health problems Play Structures Play forms can be located in the floodway but must be designed to withstand stormwaters. Safety also should be a concern. Parcourse -This type of activity involves set structures along a trail that require the user to perform some kind of excercise, such as, sit ups, chin ups, etc. Horseback Riding -Equestrian trails can be integrated with hiking and maintenance trails. This requires a softer or more natural surface than asphalt or concrete. PASSIVE Picnicking -Tables and benches can be placed at intervals or in parks along the drainageway to allow users to sit and eat. Picnicking can 147

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PARKS also take place on grassy areas in the floodway. Wildlife Observation -Providing adequate vegetational cover is maintained a variety of wildlife can be seen within a drainageway corridor. Vegetation Preserve -A wildlife area can occupy the same area where vegetation has been preserved or reintroduced. Education -A drainageway can provide an environmental education for users. The interaction of wildlife and riparian vegetation is an invaluable learning tool, as well as observing the fluctuations and changes of the water itself. Viewing -Sitting and enjoying the surrounding scenery is a form of recreation. In urbanizing areas this is could considered a respite from the noise, pollution, and traffic of the city. Different forms of parks can occur within and around a perennial drainage. These areas can provide some of the activities listed above. POCKET OR NODE PARKS -There is an emphasis placed here on a man-made or natural feature. Confluence Park at the junction of the South Platte River and Cherry Creek is a prime example of a node park. An grass ampitheater, a kayak course, and a plaza that was designed to withstand flooding are located here. LINEAR PARKS -Open space within the floodway. They provide a greenbelt system of trails and park spaces and acts as a connection to other park facilities. FLOODPLAIN PARKS -Open space reserved within the 100-year floodplain. It is utilized as a park when flows are normal and as a natural place for storm water to overflow at flood stages. The city of Littleton has reserve sections of 148

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South Platte 100-year floodplain for such parks. REGIONAL PARKS -Floodplain parks have the potential to be set aside for regional use if it is greater than 50 acres. If the park has the potential to attract users from a variety of areas as a destination point. These types of parks contain many forms of recreation. 149

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URBAN DRAINAGE & FLOOD CONTROL DISTRICT: DENVER, COLORADO The Urban Drainage and Flood Control District is a multicounty authority that provides floodplain and channel management for major drainageways in portions of Adams, Arapahoe, Boulder, Denver, Douglas, and Jefferson Counties. It is governed by a IS-member board of directors made up of 13 locally elected official and 2 professional engineers. The District provides not only coordinated floodplain management, planning, and mapping, but also comprehensive design of major drainageways. Construction and maintenance of major drainageways is administered by UD&FCD. A regional drainage criteria manual has been developed by this organization which is used by all local governments and engineers. Urban Drainage was established by special state statute and is the only organization of its kind in Colorado. The Denver Metropolitan region lies within a foothills and high plains or prairie environment. Each of these zones exhibits different characteristics in climate, topography, geology, vegetation, and wildlife. and precipitation have the most effect on the character of a drainageway. The most precipitation is received in the spring (March and April) when snowfall occurs both in the mountains and the plains. Though in the summer months rainfall can be extremely heavy during isolated afternoon thundershowers, the driest periods of the year also occur during this time. Average precipitation in this area ranges from fourteen to sixteen inches per year. Therefore, the Denver region is in a semi-arid zone and is the reason why many drainages in the vicinity are intermittent. 150

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MAJOR DRAINAGE MAP URBAN DRAINAGE & FLOOD CONTROL DISTRICT : e 151

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-, I I I -----1 I A P A H I 1-70 LIMITS OF JURISDICTION URBAN DRAINAGE & FLOOD CONTROL DISTRICT 152

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AGENCIES RELATED TO WATER RESOURCES Department of Agriculture Agricultural and Rural Economic Research Agriculture Stabilization and Conservation Service Farmers Home Administration Forest Service Soil Conservation Service Department of the Army Corps of Engineers Department of Commerce National Oceanic and Atmospheric Administration Economic Development Administration Department of Energy Federal Energy Regulatory Commission Department of Health, Education, and Welfare Public Health Service Department of Housing and Urban Development Community Planning and Development Federal Housing Administration Department of the Interior Bureau of Land Management Heritage Conservation and Recreation Service Geological Survey Fish and Wildlife Service Water and Power Resources Service Office of Water Research and Technology Department of Transportation Coast Guard Federal Highway Administration Federal Emergency Management Agency Federal Disaster Assistance Administration Federal Insurance Administration Civil Defense Preparedness Agency Small Business Administration Tennessee Valley Authority Water Resources Council National Science Foundation 153

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NATURAL SYSTEMS Water occurs on, in, and over the earth in many places and in many phases. The hydrologic cycle consists of the transformations that occur within each phase and with the motion from one location to the next. It is a closed system which has no beginning or end. Atmospheric moisture falls to the earth in the form of rain, hail, snow, or condensation. Buildings, trees, shrubs, and other plants will retain portions of this precipitation. The process in which this water never reaches the ground is called interception. Water that reaches the ground will either evaporate into the atmosphere, or will infiltrate into and below the ground surface. At times the intensity of the rainfall will reach its saturation level and puddles will begin to form. Eventually these puddles will overflow causing water to flow over the ground surface. This action is called runoff. Water that infiltrates into the ground enters the zone that plant roots occupy. This moisture may return to the atmosphere through evaporation from the soil surface or by transpiration from plants. A limited quantity of water is held by the upper soil zone. That amount is known as its field capacity. If this zone is at its capacity when more water is added, some of it passes down into a lower one which is called the saturation or groundwater zone. Water leaves this subsurface area via plant roots or by seepage into streams. Understanding of the hydrologic cycle provides a valuable framework for analyzing human modification of streams and the land surrounding them. Study of environmental conditions and systems is essential in the evaluation of drainageways for potential designs. The understanding of contributing waterways and the area around them is a primary facotr. Conceptually, a drainage basin or watershed, is exactly what is stated -a basin. It is an area of land where water drains to a common outlet at some point along a stream channel. , The largest basins covering thousands of square miles are comprised of an infinite number of smaller 158

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watersheds. The South Platte River in Denver is one of the drainages that flow into the Missouri River basin. Watershed boundaries must be defined in order to analyze flow characteristics of a site. These characteristics are a result of natural and man-made conditions. Changes within natural drainageways are generally the result of urbanization and the alteration of land use patterns. Two important impacts of this are increased impermeable surface such as roofs, concrete, and asphalt, and alteration of the landscape to allow for buildings and infrastructure. Direct effect resulting for these impacts include increased runoff and decreased infiltration due to an increase of impermeable surfaces. Increased runoff increases the quantity of peak flows as well. Soil erosion, sedimentation, and streambank erosion are other induced conditions. Due to increased use of impermeable surface for paving parking lots, streets, sidewalks, etc. The natual occurence of water infiltration into the soil, as discussed in the hydrologic cycle, is no longer possible in such parts of developed areas. Surface runoff is therefore increased. As this increased amount of runoff enters the depth of flow increases. In many cases, channels do not have sufficient capacity to handle the excess flows and water overflows the banks of the drain 159

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160 BIBLIOGRAPHY AND REFERENCES

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BOOKS Beckett, Jackson, Raeder, Inc. Soil Erosion and Sedimentation Control. Environmental Design-Fress. Reston, Virginia, 1981. Colorado Department of Highways. I-70 in a Mountain Environment: Vail Pass, Colorado. U.S. Department of Transportation, 1978. Denver Planning Office. Denver Urban Design Sourcebook. Denver, Colorado, 1982. Denver Regional Council of Governments. Urban Storm Drainage Criteria Manual, Volumes I and !l Urban Drainage and Flood Control District. Denver, Colorado, 1977. Dunne, Thomas and L.B. Leopold. Water in Environmental Planning. W.H. Freeman and Co. San Francisco, 1978. Giltner, Robert E. Denver, Colorado, Drainage Plan. 1967. Denver Planning Office. Gray, Donald H., PhD. and A. Leiser, PhD. Biotechnical Slope Protection and Erosion Control. Van Nostrand Reinhold Co. New York, 1982. Hjelmfelt, Allen T., Jr. and J.J. Cassidy. Hydrology for Engineers and Planners. Iowa State University Press. Aames, Iowa, 1975. Jellicoe, Geoffrey and S. Jellicoe. The Landscape of Man. Van Nostrand Reinhold Co. New York, 1982. Kolenkow, Robert J. Physical Geography Today: A Portrait of CPM Books. Del Mar, California, 1974. Landphair, Harlow C. and F. Klatt, Jr. Landscape Architecture Construction. Elsevier Science Publishing Co., Inc., 1979. League of Women Voters of Colorado. Colorado Water. Denver, Colorado, 1982. 161

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Lynch, Kevin. Technology. Site Planning. Massachusetts Institute of Cambridge, Massachusetts, 1971. Mann, Roy. Rivers in the City. Praeger Publishing Co. New York, 1973. Mutel, Cornelia F. and J.C. Emerick. From Grassland to Glacier. Johnson Books. Boulder, Colorado, 1984. National Crushed Stone Association. Erosion and Sedimentation Control. Quarried Stone for May 1982. Newton, Norman T. the Land: The Development of Landscape Architecture. Belknap Press. Cambridge, Massachusetts, 1971. Petts, Geoffrey E. Rivers. Butterworth and Co. London, 1983. Rutledge, Albert J. Anatomy of a Park. McGraw-Hill Book Co. New York, 1971. Say, Wayne E. and A.J. Dines. Protecting Creeksheds. Huron River Watershed Council. Ann Arbor, Michigan. Shaw, Samuel P. and C.G. Fredine. Wetlands of the United States. United States Government Printing-office. Washington, D.C., 1956. Shoemaker, Joe. Returning the Platte to the People. Tumbleweed Press. WestiminSter, ColoradO; 1981. Simonds, John 0. Landscape Architecture. McGraw-Hill, Inc. New York, 1983. Smardon, Richard C., ed. Visual-Cultural Values. Jersey, 1983. The Future of Wetlands: Assessing Allanheld, Osmun and Co. New Spirn, Anne W. The Granite Garden. Basic Books, Inc. New York, 1984. Tourbier, J.T. and R. Westmacott. Water Resources Technology. Urban Land Institute. Washington, D.C., 1981. 162

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U.S. Department of Interior, Bureau of Reclamation. Canals and Related Structures, Design Standards, No. Office of Chief Engineer. Denver, Colorado. 1967. U.S. Department of Agriculture, U.S. Forest Service. National Forest Landscape Management: Chapter 1-The Visual Management System. Government Printing Office. Washington, D.C., 1974. Untermann, Richard and R. Small. Site Planning for Cluster Housing. Van Nostrand Reinhold Co., Inc. New York, 1977. Urban Drainage and Flood Control District. Guidelines for Development and Maintenance of Natural Vegetation. Denver, Colorado, 1984. Urban Drainage and Flood Control District. The South Platte River-Chatfield Brighton. Denver, Colorado, December 1985. Urban Land Institute, American Society of Civil Engineers, and National Association of Home Builders. Stormwater Management. Washington, D.C., 1979. Weller, Milton W. Freshwater Marshes. University of Minnesota. Minneapolis, Minnesota, 1981. Whipple, William, N. Grigg, T. Grizzard, C. Randall, R. Shubinski, and L.S. Tucker. Stormwater Management in Urbanizing Areas. Prentice-Hall, Inc. New Jersey, 1983. ARTICLES Bennetts, Dave. "Routine Maintenance of Flood Control Facilities." Flood Hazard News. Urban Drainage and Flood Control District. Vol. 15, No. 1, December 1985, p. 7. DeGroot, William G. and L.S. Tucker. "Wetland Bottom Channels-An Emerging Issue." Flood Hazard News. Urban Drainage and Flood Control District. Vol. 15, No. 1, December 1985. pp. 1 & 7. 163

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DeGroot, William G., L.S. Tucker, and M.R. Hunter. "Multiple Use Concepts in Floodplain Management.'' Flood Hazard News. Urban Drainage and Flood Control District. Vol. 15, No. 1, December 1985, Supplement, pp. 1-4. Fowler, Lloyd F. and S.N. Wolfe. "Urban Creekside Design Features Parallel Streets." Civil Engineering. Vol. 52, No. 6, June 1982, pp. 72-74. Gunn, Clare A. "River Walk Generatess Strong Positive Response." Landscape Architecture. April 1973, pp. 236-238. Hoffmaster, B. H. "Design and Construction Notes." Flood Hazard News. Urban Drainage and Flood Control District. Vol. 15, No. 1, December 1985, pp. 4-5. Jewell, Linda. Architecture. "Alternatives to Channelization. Landscape Vol. 71, July 1981, pp. 488-490. Jontos, Robert J., Jr. and C.P. Allen. for Non-Structural Sediment Control." March 1984, pp. 88-89. "Using Vegetation Public Works. Shields, Douglas F., Jr. "Environmental Features For Flood Control Channels." Water Resources Bulletin. Vol. 18, No. 5, October 1982, pp. 779-784. Westmacott, R. "The Rediscovered Arts of Twilling and Wattling." Landscape Architecture. Vol. 75, No. 4, July/August 1985, pp. 95-98. Whipple, William Jr., J.M. DiLouie, and T. Pytlar, Jr. "Erosion Potential of Streams in Urbanizing Areas." Water Resources Bulletin. Vol. 17, No. 1, February 1981, pp. 36-45. Winter, Roy. "Making the Most of a Stream: Gently Flowing Through the Village." Landscape Architecture. July 1975, pp. 312-315. REPORTS 164

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Barlett, Jim. Littleton." Education. " Platte River Valley: Two Choices for Western Interstate Commission for Higher Boulder, Colorado, 1973. Hydro-Triad, Ltd. Major Drainageway Planning-Mcintyre Gulch. Prepared for Urban Drainage and Flood Control District and the City of Lakewood, Colorado. 1977. Merrick and Company. Major Drainageway Planning-Little Creek. Prepared for Urban Drainage and Flood Control District, Jefferson County, Arvada, Westminster, and Adams County, Colorado. 1979. Merrick and Company and Harman, O'Donnell and Henninger. Major Drainageway Planning-Cherry Creek. Prepared for Urban Drainage and Flood Control District, City and County of Denver, City of Glendale, and Arapahoe County, Colorado. 1977. Sellards and Griggs, Inc. Gulch and Tributaries. Flood Control District, Denver. 1977. Flood Hazard Area Delineation-Dry Prepared for Urban Drainage and City of Lakewood, and County of University of Wisconsin-Extension. Information notebook from the Biotechnical Slope Protection and Erosion Control Conference. Department of Engineering. September 1984. Wright McLaughlin Engineers. Major Drainageway Planning-South Lakewood Gulch. Prepared for Urban Drainage and Flood Control District and City of Lakewood, Colorado. 1978. PERSONAL INTERVIEWS/PHONE CONVERSATIONS Bennetts, Dave. Field Maintenance Supervisor. Urban Drainage and Flood Control District, Denver, Colorado. Spring 1986. Blish, Mary Anne. Associate. McLaughlin Water Engineers, Ltd., Denver, Colorado. Winter 1986. 165

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DeGroot, William G. Chief, Floodplain Management Program. Urban Drainage and Flood Control District, Denver, Colorado. Spring 1986. Hindman, Paul. Project Engineer. Urban Drainage and Flood Control District, Denver, Colorado. Fall 1985 and spring 1986. Weber-Quinn, Mary. Supervisor, South Platte Park. South Suburban Metropolitan Recreation and Park District, Littleton, Colorado. Fall 1985. Wenk, William. Landscape Architect. William Wenk and Associates, Denver, Colorado. Phone conversation. Fall 1985. 166