RECLAMATION OF SURFACE MINED LAND BASED ON VISUAL AND FUNCTIONAL ATTRIBUTES OF LANDFORM
THOMAS L. SULLIVAN
DEPARTMENT OF DESIGN AND PLANNING UNIVERSITY OF COLORADO AT DENVER
A 1~ f
LP 1110* A '11
RECLAMATION OF SURFACE MINED LAND BASED ON VISUAL AND FUNCTIONAL ATTRIBUTES OF LANDFORM
Submitted as Partial Fulfillment of the Requirements for the Degree Master of Landscape Architecture
Presented to the Faculty of the College of Design and Planning Graduate Program of Landscape Architecture University of Colorado at Denver
Thomas L. Sullivan
This study addresses the reclamation of surface mined land in the eastern foothills of the Rocky Mountains. Emphasis is placed upon an understanding of geomorphology, and how this can be applied to land reclamation. The case study deals with the proposed South Draw Quarry, owned by the Colorado Rock Company of Boulder.
TABLE OF CONTENTS
List of figures and tables..................................v
LIST OF FIGURES AND TABLES
1. Study Area..............................................3
3. Nine-Unit Land Surface Model............................7
4. Site Location..........................................15
5. Geology Map............................................17
6. Soils Map..............................................19
7. Vegetation Map.........................................21
8. Mining Operations......................................25
9. Aerial View of Site....................................27
10. Exposed Bedrock........................................29
11. General Landform Categories............................30
12. Landform Components....................................31
13. Rock Sculpting.........................................33
14. Timber Clearing........................................33
15. Existing Contours......................................34
16. Post-Mining Contours...................................35
17. Overhead View of Post-Mining Contours..................36
18. Illustrated Plan of Reclaimed Site.....................37
19. Naturally Occurring Rocky Slope........................39
20. Benched Slope Sections.................................40
21. Bench Detail...........................................41
22. Quarry Floor Detail....................................43
23. Natural Drainage Area..................................44
24. Wildlife Habitat on the Quarry Floor...................49
1. List of Wildlife Species...............................23
2. Planting List for Upland Areas.........................46
3. Planting List for Lowland Areas........................46
4. Planting List for Grasses and Forbs....................47
The Front Range is facing a population boom. By the year 2000 over one million more people will live here. The physical development that accompanies this influx will require huge amounts of raw materials.
Crushed rock is one of these materials. Crushed rock is used in the construction of roads, sidewalks, water and sewer lines, building foundations, and other necessities of contemporary life. It is a basic product for which there is no substitute. Because of increasing transportation costs, mining companies are looking for sources of crushed rock close to the population centers. The foothills west of Denver are an excellent source of this material.
In the past, the mining of our natural resources has not always responded to the environmental demands of the future. According to Aldo Leopold, "We abuse the land because we regard it as a commodity belonging to us. When we see the land as a community to which we belong, we may begin to use it with love and respect." Landscape architects are expected to be stewards of the land. Yet, as we specify construction materials in our designs, it is all too easy to ignore how these materials are obtained. Every time we specify concrete or asphalt, bricks or blocks, somewhere someone digs a little deeper into the ground in order to provide the materials that we have demanded. While serving the needs of individuals, we must not ignore the needs of the larger community to which we belong.
Analysis of the natural landscape is the first step in the development of a reclamation plan. Classification of the landscape in terms of vegetation patterns (spruce-fir, ponderosa pine-meadow, mixed shrub, etc.) is a common approach. However the vegetation is merely an expression of microclimate and soils, which in turn are a function of the shape of the land, i.e., the landform. Therefore the development of a regional landform classification system could form the basis for reclamation of a particular site.
Hypothesis: Through analysis of characteristic landforms, a
reclamation plan can be designed for surface mined land that recreates the visual and ecologic functions of the natural landscape.
Scope: The slope of this project is limited to the lower montane
region of the eastern slope of the Front Range (see Fig. 1).
Fip. 1 Study Area
This project is divided into two parts. The objective of the first part is to develop a physical description of regional landforms. This is accomplished by reorganizing existing environmental data (from soil surveys, vegetation analyses, etc.) into blocks of information based on established landform categories.
The objective of the second part is to develop a specific reclamation plan that reflects the landform characteristics established in the first part of the project. This methodology is shown schematically in Fig. 2.
REGIONAL LANDFORM ANALYSIS
m i=n trm
The study area corresponds to the area commonly known as the "foothills". Topographically the area is characterized by narrow ridges and deep valleys cut into metamorphic and intrusive igneous rock. As is typical of all erosional landscapes, the area is comprised of three basic landform types: peaks and ridge tops, slopes and canyon walls, and valley floors.
Geomorphologists have broken down these categories still further. Fig. 3 shows a land surface model used to describe landform in more detail. Each unit is characterized by a different set of geomorphic processes that account for its present form. While not all of these units are necessarily present in every geomorphic profile, all erosional landscapes incorporate some of these units in various combinations and orders.
The general ecology and visual character of an area are determined by the type of landforms present. Therefore it is necessary to understand the visual and functional attributes of these landforms in order to create a reclaimed landscape that responds to human needs and yet appears natural.
For the purposes of this study, only the most general landform categories are to be described: valley floors, slopes and canyon walls, and peaks and ridge tops. This descriptive information is derived from the following references as well as from personal observation: From Grassland to Glacier,, Mutel; Ecosystem Guide for Mountain Land Planning, Lynch; draft information prepared by the Jefferson County Soil Conservation District.
Channel Wall-Stream Channel
Bloom,Arthur L., 1973,
4 STREAM CHANNEL
3 STREAM CHANNEL WALL
2 ALLUVIAL TOESLOPE
1 COLLUVIAL FOOTSLOPE
In some areas, a gently sloping to nearly level surface, 500 feet or more in width; in other areas, much narrower; locally restricted to stream width; stream gradients range from less than 2% to more than 20%.
Boulders and fine grained alluvium in stream channels and local valley flats; alluvium may merge upslope with colluvium of canyon walls.
Soils usually have a high organic content and exist over unconsolidated material deposited by water or glacial action; soil moisture is typically high; there is considerable water movement laterally through the subsurface gravels.
Usually quite shallow-within 1 to 5 feet of the surface; areas appearing to be dry in late fall are likely to be soggy and saturated throughout the spring and early summer.
Three major vegetation types exist: dry meadow, wet meadow, riparian. Dry Meadow: Members of the grass family dominate; many species present
(approx. 150); at lower elevations, bunch grasses dominate: needle-and-thread, mountain muhly, june-grass, blue grama, wheatgrass; weedy forbs are also numerous; yarrow, pasture sagebrush, ponderosa pine, rocky mountain juniper, and dry shrub clumps may also be present in small numbers. Wet Meadow: Small number of species; one species often covers a large area;
primarily members of the sedge and rush families; spike rush, sedges, Canadian reed grass, and tufted hairgrass are common. Clumps of willow and shrubby cinquefoil may be present. Riparian: Tree groves and shrub thickets sometimes interspersed with wet meadows. Species composition is correlated with altitude and exposure. Trees: alder, cottonwood, willow, birch; shrubs: wild plum, chokecherry, willow, hawthorn. Herbaceous understory: forbs, grasses, sedges, rushes, vines, mosses, lichens,
Small mammals, birds, and their associated predators are common. Large mammals, particularly deer and elk take advantage of the high food production capability of this area. In addition to their importance as foraging sites for herbivores, meadows are also important as hunting areas for predatory birds. Edges between meadows and forest are an important habitat for both herbivores and carnivores that depend on the forest for cover and the meadow for food. Large numbers of small mammals and nesting birds depend on riparian areas for habitat.
The surrounding slopes combine with the valley floor to create an enclosed landscape. The degree of enclosure depends on the width of the valley floor. The dominant visual elements are line and color. This results from the linear pattern of riparian vegetation, which, being deciduous, contrasts with the surrounding evergreen slopes. This linearity and color contrast creates a sequential visual experience that accentuates the landform.
LANDFORM SLOPES AND CANYON WALLS
1 CONVEX CREEP SLOPE
2 FALL FACE
3 TRANSPORTATIONAL MIDSLOPE
This is the predominant landform of the study area. Rough, steep surfaces (25 degrees to vertical) rise abruptly up to 1500 ft. above the valley floors and drainages. Areas of more moderate slope occur locally within steep canyon walls. Large rock outcrops commonly occur along the major drainages. Orientation greatly affects the character of the surface features.
These landforms are the product of erosion and weathering of igneous and metamorphic rocks: Precambrian granites to granodiorites, Tertiary quartz monzonites to diorites. Sedimentary rocks of Paleozoic and Mesozoic age occur in a narrow strip at the east edge of the study area.
Soils are shallow and well-drained; formed in material weathered from igneous and metamorphic rocks; rapid permeability; low capacity for water; rapid run-off; high water erosion hazard; effective rooting depth less than 20 in. (deeper at base of slopes); soil reaction is acid on north facing-slopes, neutral on those facing south.
Variable with slope aspect: ponderosa pine dominates south facing slopes and ridgetops. Douglas fir forms dense stands on steep north facing slopes. Douglas fir and ponderosa pine often form mixed stands. The abundance of pine increases and density decreases as soil moisture decreases (as slopes face more to the south, as altitude decreases, or as soils become coarser and better drained). South facing slopes are often a mixture of dry meadow, ponderosa pine, and dry shrub ecosystems. Shrubs: bitterbrush, buckbrush, mountain mahogany, three-leaf sumac, smooth sumac, ninebark, wild rose, squaw currant, serviceberry. Pine understory plants: wild geranium, whiskbroom parsley, sticky cinquefoil, sedges,
composites, Oregon grape. Fir understory plants: common juniper, kinnikinnic, Oregon grape.
The density and number of species of small mammals and birds are intermediate between those of dense conifer ecosystems (spruce-fir, lodgepole pine) and deciduous mountain ecosystems (riparian, aspen).
Animal density increases as the forest becomes more open and understory becomes more diverse. Mammals: tree and ground squirrels, chipmunks, mice, rabbits, skunks, badgers, porcupines, coyotes, bobcats, black bear, mule deer, elk. Birds: Stellar's jays, magpies, downy and hairy woodpeckers, white breasted, red breasted, and pygmy nuthatches, common ravens, mountain chickadees, gray-headed juncos, robins, pine siskins. Common habitat for the bushy-tailed woodrat, yellow-bellied marmot, and deer mouse.
Cliffs, talus, and rock outcrops are feature objects that visually donimate the surrounding landforms. The form, color, and texture of the rocky areas provide contrast and visual variety. North facing slopes have a uniform, fine texture resulting from the vegetative cover. South facing slopes have a more coarse and variable texture. This vegetative texture is the dominant visual element of slopes lacking areas of bare rock.
LANDFORM: PEAKS AND RIDGE TOPS
2 SEEPAGE SLOPE
Very rough, steep surfaces; very narrow and jagged in areas of metamorphic bedrock; more rounded and dome-like in areas of granitic bedrock.
These landforms are the products of erosion and weathering on igneous and metamorphic rocks: Precambrian granites to granodiorties, Tertiary quartz monzonites to diorites.
Exteremely thin or non-existent soil layer; formed in material weathered from igneous and metamorphic rocks; rapid premeability; low capacity for water; rapid run-off.
Vegetation thin soils described
varies with orientation; generally is very sparse due and exposed conditions. Species composition follows for slopes and canyon walls.
to the patterns
Because of the exposed conditions and sparse vegetation, the density and numbers of resident species is much lower than in the other categories.
Form is the dominant visual element; the texture and color of bare rock areas provide variety and contrast; the peaks are "feature objects" in the landscape.
RECLAMATION OF THE SOUTH DRAW QUARRY
The South Draw Quarry is being proposed by the Colorado Rock Company, an affiliate of the Flatiron Companies of Boulder. The quarry is to be conducted as a surface mine. Geologic investigations indicate that at least 100 million tons of construction aggregates are available. Based on an average recovery rate of 2 million tons per year, the mine will have a life of 50 years. Because of this time span, the post-mining land use is not definite at this time. This project will consider wildlife habitat as the primary post-mining use.
The South Draw Quarry site is located in Jefferson County, just south of the Boulder County line. The permit area contains approximately 320 acres. The site is in the upper portion of the South Draw Basin, approximately two miles above the draw's confluence with South Boulder Creek. The draw is oriented to the northeast and is surrounded by Scartop Mountain (8790 ft.) on the west, Crescent Mountain (8945 ft.) on the south, and Eldorado Mountain (8335 ft.) on the east. The proposed mining area ranges in elevation from 7225 ft. to 7800 ft.
Fig. 4 Site location
According to the geologic investigation done by the Colorado School of Mines Research Institute, the South Draw site contains metamorphic and intrusive igneous rocks of Precambrian age. The metamorphic rocks, represented by the metasedimentary quartzite, are the oldest rocks. The Boulder Creek Granodiorite is next oldest, followed by the quartz monzonite. Along the stream bottoms recent alluvium is present, ranging in thickness from 5 to 15 feet deep. Colluvium is present at the base of the steep hillsides. The investigation determined that the quartzite, granodiorite and quartz monzonite represent excellent sources of construction aggregate, and that no unique geologic features would be destroyed or damaged by the mining operation.
There are four main soil units on the South Draw site, according to the Jefferson County Soil Conservation District: Rogert-Herzman-Rock outcrop complex; Frisco stony sandy loam; Hiwan-Copperdale-Lakehelen variant complex; and Rock outcrop, igneous and metamorphic. The first three type share the following characteristics:
1. Runoff is rapid.
2. Possibility of water erosion is high.
3. Possibility of soil blowing is slight.
4. Shrink-swell potential is low.
5. Rock fragment range is 35-80 percent.
In the vegetation study prepared by Warren R. Keammerer of Stoecker-Keammerer & Associates, the vegetation of the South Draw site is described as "typical of what would be expected to grow at this elevation in the foothills." Open ponderosa pine forests, meadows, and douglas fir forests occur in characteristic patterns. More than 100 plant species have been observed on the South Draw site. This relatively high number results from the site's transitional location, between the mountains and the plains. Keammerer classified the vegetation into four types and described them as follows:
Dry Meadow/Open Woodland Type. The dry meadow/open woodland type occurs throughout the site primarily on south-facing slopes. The major tree species, ponderosa pine (Pinus ponderosa), occur as scattered individuals. There is no closed canopy. Major grasses include various species of needlegrass (Stipa spp.) and wheatgrasses (Agropyron spp.)
Dense Ponderosa Pine and Douglas-fir Forest Type. This type occurs on the steep north-facing slopes on the site. The major species are ponderosa pine and Douglas fir (Pseudotsuga menziesii). Tree density is approximately two to four times greater than in the open woodland type.
The understory in the dense woodland type is very sparse with only a few scattered plants. Typical species include mountain parsley (Aletes acaulis), whisk fern (Harbouria trachypleura), and Oregon grape (Mahonia repens).
Aspen Woodlands. Aspen woodlands are very restricted and occur in only a few areas on the site. These stands are on north-facing slopes. The primary species is quaking aspen (Populus tremuloides). Most of the individual trees are small and appear to be growing under stressed conditions. It appears that the natural environment at this location is marginal in its capabilities to support aspen. Understory shrub species include snowberry (Symphoricarpos orerophilus) and woods rose (Rosa woodsi i).
Disturbed Areas and Roadsides. The vegetation on the disturbed areas and roadsides is composed primarily of annual weedy species. Major species include prickly lettuce (Lactuca serriola), horseweed (Conyza candensis), cheatgrass brome (Bromus tectorum) and ground smoke (Gayophytum ramocissiumu). This type occurs on roadsides as well as along the Denver and Rio Grande Western Railroad right-of-way which crosses the site.
Dense ponderosa pine and douglas fir forest
Disturbed area and roadsides
Fig. 7 Vegetation Map
The major wildlife habitats on the site are the dense coniferous for north-facing slopes and the open woodland and meadows on the south-f slopes. A small amount of riparian habitat, primarily small stands aspen and alder thickets, occurs in the South Draw drainage. This d is a small ephemeral stream, fast-flowing during runoff but dry duri summer.
es t on
ac i ng
ra i nage
In their report evaluating wildlife conditions, Stoecker-Keammerer & Associates concluded that "the wildlife habitat on the South Draw property is typical of much of the surrounding area with a similar topography. No critical or especially important wildlife habitats were found. The property would be rated as having fair to good habitat conditions". Table 1 lists wildlife species that they identified during four site visits.
Table 1. List of Wildlife Species Identified by Stoecker-Kearamerer t Associates During Site Visits in 1980 and 1981.
Common name Scientific Name
MAMMALS Nuttall's cottontail Abert's squirrel Chickaree
Northern pocket gopher Mule deer
Red-tailed hawk Turkey vulture Blue grouse Common flicker Hairy woodpecker Mourning dove Steller's jay Common raven Black-billed magpie Mountain chickadee White-breasted nuthatch Red-breasted nuthatch Townsend's solitaire Dark-eyed junco Gray-headed junco Mountain bluebird American robin Hermit thrush Western tanager Violet-green swallow Rose-breasted grosbeak
Sylvilagus nuttallii Sciurus aberti Tamiasciurus hudsonicus Thomomys talpiodes Odocoileus hemionus
Buteo jamaicensis Cathartes aura Dendragapus obscurus Colaptes auratus Picoides villosus Zenaida macroura Cyanocitta stelleri Corvus corax Pica pica Parus gambeli Sitta carolinensis Sitta canadensis Myadestes townsendi Junco hyemalis Junco caniceps Sialia cumicoides Turdus migratorius Catharus guttata Piranga ludoviciana Tachycineta thalassina Pheucticus ludovicianus
The South Draw Quarry will be conducted as a surface mine. Removal of vegetation and topsoil in a given area is the first step. Whenever possible, topsoil will be stockpiled. Then, using a rock drill and explosives, the exposed rock is fragmented. The "shot" rock is then processed for shipment from the site via the Denver and Rio Grande Western Railroad.
The mine plan is based on a benching process which starts with the creation of the pit floor. This will be accomplished by filling the South Draw drainage at its intersection with the railroad. The drainage will be routed around the pit floor. The pit floor can then accomodate the railroad spur for loading activities as well as crushing and screening equipment and stockpiles.
Following establishment of the pit floor, a into the south-facing slope of Stage 1 (see been mined and processed from these initial made, followed by a third, and so on. This from the southeast to the northwest and from completion of Stage 1, this process will be
series of benches will be cut Fig. 8). Once the material has cuts, a second series will be stairstep process will proceed top to bottom. Following repeated in Stage 2.
Fig. P, Mining Operations
1. To contour the topography in a way that maintains the character of the surrounding landscape and provides visual variety within an appropriate range of contrast.
2. To establish vegetation that will be harmonious with that of surrounding areas, will survive on natural precipitation, and will act as erosion control.
3. To create wildlife habitat for appropriate species.
The general reclamation concept at the South Draw Quarry is not to restore the land to its exact, pre-mining appearance. Rather, the idea is to create a new landscape comprised of appropriate landforms that are characteristic of the region. This approach is similar to that used by the Colorado Department of Highways on the nationally acclaimed Vail Pass project. The task of fitting an interstate highway into an ecologically sensitive mountain environment was a major challenge in terms of both functional and aesthetic considerations. In addition to steep slopes, very erodible soils, and the short growing season (at an elevation 3,000 feet higher than South Draw), they had to contend with the problem of visual compatibility in a spectacularly scenic area. They attribute the success of the project to the use of landshaping methods designed to simulate natural landforms. Reclamation at South Draw will be based on an understanding of how these landforms affect the ecologic and visual character of the area.
Mining at South Draw will expose the bedrock. This same rock formation has been exposed by natural processes in areas immediately to the north and south of the site (Fig. 10). Much of the scenic quality of Coal Creek Canyon and the Eldorado Springs area is attributable to the dramatic rock formations. The cliffs, spires, and outcrops are focal points in the landscape. Their forms, textures, and colors add visual variety to the area. National Forest Landscape Management Vol 1 states, "Visual variety is desirable. Landscapes rich in variety are likely to be more appealing than ones tending toward monotony." In Reclamation of Drastically Disturbed Lands, Randall, Johnson, and Pagoulatos state that it is possible for reclaimed mines on steep, wooded slopes to heighten landscape diversity. Reclamation of the South Draw Quarry will strive to emulate the rugged and visually diverse character of the adjacent landforms.
In terms of the general landform categories, the reclaimed landscape at South Draw will primarily consist of "Valley Floor" and "Slope and Canyon Wall". There will be a small area of "Ridge Top" at the northern end of the site. The boundaries of these landforms are determined by the upper mining limits and the prescribed average slopes of the quarry wall(45 degrees) and the quarry floor(2%).
General Landform Categories
By applying a knowledge of geomorphic processes (as expressed in the land surface model), the general landforins can be divided into their respective components. Reproducing these components in the reclaimed landscape will result in a more natural looking and stable slope profile. Since the form and slope of each component reflect the natural processes of erosion and weathering the reclaimed landforms will not appear uniform and obviously man-made.
These landforms will be created using the same techniques of rock sculpting and slope molding as used on the Vail Pass project. These landscape treatments were so successful that it is difficult to distinguish between the old and new landforms.
The rock cuts typically seen along highways do not contain the diverse fracture lines and irregularities found in natural rock faces. These cuts have been designed to meet only the requirements of slope stability and balanced cut and fill material. At South Draw the aesthetics of the rock cuts will be a major concern. In order to create a natural looking rock face the blasting charges will be designed to break the rock along natural fracture lines where possible. Fig.13. shows the staggered bench effect to be created at the upper mining limit.
Following the final blasting, heavy equipment will "mold" some of the slopes into more rounded forms. In Fig.n. note the gradual transition from the existing slope to the rock faces. Also note how the draws and ridges in the upper area are continued into the mined area in order to blend the old and new landscapes.
Selective thinning methods will be used to create a transitional forest edge. Taller, older trees will be cut, leaving the younger ones. As shown in Fig.l^. openings will be cut into the forest to create an irregular edge.
Figures 1S.,16., and 17. show the before and after mining contours. Because of the Large contour interval (40 ft.) only large scale landforms are depicted. Fig. IS. is an illustration of the reclaimed area. Again, because of the scale, only general patterns of topography and vegetation are shown.
Fig;. 1^ Timber Clearing;
Fig. 15 Existing contours,100king up South Draw. Contour interval:40 ft.
Fig. 16 Post-mining contours
Note: quarry floor appears flat because
of the large contour interval.
Fifp. 17 Overhead view of post-minine; contours. White line represents mining limits.
Fis:. Illustrated plan of reclaimed site
The reclaimed quarry slopes will have a visual character similar to the rocky slope shown in Figure 12. The area shown is located approximately one and a half miles northeast of the quarry site and is geologically similar. Note the steep rock faces separated by flatter areas of talus and scattered vegetation. These irregular landforms will be simulated by using a variable benching pattern as shown in Figure 13. The horizontal dimensions will be multiples of 20 ft. while the vertical faces will vary
as multiples of 30 ft. Some faces may be as high as 240 ft.
The angle of these landforms will also vary. Some benches will slope
slightly to the inside (2%) in order to control and detain runoff. This will provide additional moisture for vegetation and wildlife. Other benches will drain outward but with a maximum slope of 30% in order to minimize erosion. In order to prevent a uniform reflective surface, the angle of the rock faces will vary between 70 and 90 degrees. These faces will be given a rough texture by setting the final blasting charges in a given area in an irregular pattern.
Areas of loose rock will be left at the base of the faces to simulate talus. The edges of the benches will be rounded where possible in order to create the appearance of a naturally eroded landscape. Similarly, at the upper limit of mining, there will be a transitional slope of increasing steepness rather than an abrupt cliff. This will also be a cue to people or animals walking downhill that steeper, rougher terrain lies ahead. Between the benched slope and the quarry floor, there will be a gently sloping area (10-30%) at least 60 ft. in width that will simulate the transportational midslope. Areas of talus and large boulders will create the impression of a naturally evolved landscape.
Fig. 20 Slope sections showing possible combinations of benching patterns.
60 ft. ROCK FACE
Variable face angle
Ledge with overhang
Rounded at top
40 ft. BENCH
2% slope to inside Planting pockets(3-4 ft. deep)
20 ft. BENCH
20$ slope to outside Talus
The reclaimed quarry floor will consist of gently rolling slopes and meadows with meandering drainages. Generally, the slopes will be less than 20% as shown in Fig. 22. Large boulders will be placed irregularly in the higher areas and along the drainages to give the impression of a naturally eroded landscape. These rocks will either be set into the ground or be partially buried so that they appear to have been in place for some time. Smaller rocks will also be used in the drainages to decrease water velocity, provide niches for plants, and to create visual diversity. Rock placement in the drainages will be similar to that shown in Fig. 23.
On the Vail Pass project major drainages and streams were re-routed using these techniques. The situation there was more difficult than at South Draw because of the much greater volume of water, the high sediment content, and the necessity to maintain fish habitat. In spite of these problems, the new water courses are now stable, clear, and support healthy fish populations. They demonstrate that with proper attention to detail, a man-made landscape can simulate nature both ecologically and visually.
STREAM CHANNEL WALL
$ SLOPE WIDTH
3-15ft. 2-20 ft.
10-20$ 20-100 ft
Fig. 22 Quarry floor detail
The depth of topsoil on the quarry slopes and floor will vary. Some areas on the slopes will be left bare. Areas to be seeded will get 6-12 inches of soil. Planting pockets for trees and shrubs will be backfilled with 3 to 4 feet of soil. This slight slope of the benches and footslopes precludes the need for compaction of the soil or erosion control measures.
In areas where supplemental watering is not possible because of inaccessibility, direct seeding and placement of bare root seedlings will be the revegetation method. In lower areas where supplemental watering is possible, larger, potted stock will be planted. These plants will require two years of maintenance and then will survive on natural precipitation.
Only species already found in the area will be used in the revegetation process. Plants will be placed in natural patterns and appropriate microclimates. Using a variety of sizes and avoiding linear planting patterns will help give the reclaimed area a natural appearance. Planting rates will be heavier on north facing slopes than on those facing south. Tables 2 and 3 list tree and shrub species that will be planted in the upland areas. Table b lists grasses and forbs that will be drilled on relatively flat terrain and broadcast at approximately double the drilled rate on steeper or less accessible slopes. As mentioned in the previous section, some areas will be left bare. Therefore Tables 2-k do not imply a uniform planting rate throughout each landscape category.
TABLE 2 - PLANTING LIST FOR UPLAND AREAS
PLANTING RATEONDIVIDUALS/ACRE TREES NORTH-FACING SOUTH-FACING
Douglas-fir (Pseudotsuga menziesii) no -
Ponderosa Pine (Pinus ponderosa) 100 50
Rocky Mountain Juniper (Juniperus scopulorum) - 25
Quaking Aspen (Populus tremuloides) 30 -
SHRUBS Wax Currant (Ribes ccreum) 25 25
Common Juniper (Juniperus communis) 50 25
Oregon Grape (Mahonia repens) 50 75
Scrviceberry (Amelanchier alnifolia) 50 25
Smooth Sumac (Rhus glabra)
TABLE 3 PLANTING LIST FOR LOWLAND AREAS
Alder (Alnus tenuifolia) 25
(Populus angustifolia) 125
Colorado Blue Spruce
(Picea pungens) 25
Red Dosier Dogwood
Cornus stolonifera) 100
Willow (Salix spp.) 75
Table ^ PLANTING LIST FOR GRASSES AND FORI3S
GRASSES PURE LIVE SEED (LBS)/ACRE/DRILLED
Western Wheatgrass 3.00
Slender Wheatgrass 3.00
Little Bluestem 2.00
Sideoats Grama 3.00
Blue Grama 3.00
Smooth Brome 1.00
Needle-and Thread Grass 1.00
Green Needlegrass 1.00
FORBS Western Yarrow 0.25
Fire weed 0.25
Blanket Flower 0.25
Rocky Mountain Penstemon 0.50
Wildlife habitat is defined by the presence of three factors: food, cover, and water. The reclaimed landscape will incorporate all three using a variety of methods.
After the vegetation is established, the quarry floor will support a wide variety of animal species. Meadows are important foraging areas for both large and small mammals. Predatory birds use meadows as hunting grounds. Shrubby meadows on south-facing slopes that remain snow-free are utilized as winter range by mule deer. The wetter areas at the base of the slopes and in the drainages will be particularly valuable places for wildlife.
The animal density and number of species are typically high in this type of habitat. This is due to the moisture, diverse vegetation, and the availability of den and nest sites. Numerous, non-resident species are also attracted to these areas by the abundance of prey, as well as by the water.
The drier, upland slopes, talus, and rock faces will also provide habitat. In From Grassland to Glacier, Mutel states, "The fauna of these shrubby, rocky areas is rich and distinctive. Shrubby, rocky ecosystems below 8,000 ft. have more mammal species than any other of our mountainous areas." Shrubs provide an abundance of food for animals by rapidly recycling nutrients into fruits, seeds, and leaves. Particularly in rocky areas, shrub communities provide protected den and nest sites. Additional cover will be provided by creating ledges and niches in the rock faces during blasting. These ledges will also provide sites for raptor nests. Creating depressions and inward slopes on the benches will provide additional water for both plants and animals.
The variety of plants used to revegetate the site will provide forage for herbivores as well as sites for dens and nests.
Drainages through the reclaimed quarry floor will provide easy access to water that has historically flowed through the site.
The quarry floor will provide a valuable hunting area for predatory species.
Fig. 2k Wildlife habitat on the quarry floor
Ledges and niches in the rock faces will provide protected areas for dens and nests.
Fig. 25 Wildlife habitat on the benches
Reclamation of the South Draw Quarry provides an opportunity to increase the ecologic as well as visual diversity of the area. Once the vegetation is stabilized, the gently rolling valley floor and the rocky ledges and cliffs will provide excellent wildlife habitat. Because of the rugged and rocky character of the surrounding landscape, the new landforms will not appear as totally foreign and unnatural elements. The cliffs and rock outcrops created as part of the Vail Pass project are a good example of how this approach can work.
Reclamation will proceed concurrently with the extraction process. The shaping of the landforms will actually be the final step of the extraction process. Reclaiming concurrent with extraction ensures that a minimum amount of land is disturbed at any one time. It also allows for a continual monitoring and evaluation process over the life of the project. Improvements or changes can be made as necessary.
The regional landform characteristics developed in the first part of this study were useful in gaining a general understanding of the foothills landscape. They provided general guidelines for the reclamation of the South Draw Quarry. Although economics imposed major limitations on the reclamation plan, the reclaimed landscape at South Draw should not appear totally out of character with its surroundings.
SINGLE VOLUME WORKS
Baxter, John. Site Planning for Sand and Gravel Operations. University of Illinois, 1969.
Bloom, Arthur L. Geomorphology. Englewood Cliffs, NJ: Prentice-Hall,
Cooke, R.V., and Doornkamp, J.C. Geomorphology in Environmental Management. Oxford, England, Clarendon Press, 1974.
Johnson, Craig. Practical Operating Procedures for Progressive
Rehabilitation of Sand and Gravel Sites. University of Illinois.
Marr, John W. Ecosystems of the Eastern Slope of the Front Range in Colorado. Boulder, CO: Land Grant Publishing Co., 1976.
Rodeck, Hugo G. Natural History of the Boulder Area, Boulder, CO: University of Colorado Museum, 1964.
Schaller, Frank Lands.
W. and Sutton, Madison Wise.:
Paul. "Reclamation of Drastically Disturbed American Society of Agronomy, 1978.
Way, Douglas S. Terrain Analysis. Ross, Inc., 1978.
Dowden, Hutchinson &
Colorado Department of Highways, 1-70 in a Mountain Environment, Vail Pass, Colorado.
Colorado State Forest Service, Ecosystem Guide for Mountain Land Planning, 1974. ----1-------------------------------------
Jefferson County, Colorado, Mineral Extraction Policy Plan, 1977.
U.S. Department of Agriculture, Forest Service, National Forest Landscape Management, Vol. 1, Agricultural Handbook No. 434, 1973.
U.S. Department of Agriculture, Forest Service, National Forest Landscape Management, Vol. 2, Chapter 4 (Roads), Agricultural Handbook No. 483, 1977.
U.S. Department of Agriculture, Forest Service, National Forest Landscape Management, Vol. 2, Chapter 5 (Timber), Agricultural Handbook No. 559, 1977.
U.S. Department of Agriculture, Forest Service, Wildlife Habitats in
Managed Forests in the Blue Mountains of Oregon and Washington, Agricultural Handbook No. 533, 1979.
U.S. Department of Agriculture, Forest Service, User Guide to Soils, Mining and Reclamation in the West, General Technical Report Int-68, 1979.
U.S. Department of Agriculture, Forest Service, User Guide to Vegetation, Mining and Reclamation in the West, General Technical Report Int-64, 1979.
U.S. Department of the Interior, Bureau of Land Management, Mule Deer Habitat Guidelines, Technical Note No. 336, 1979.
U.S. Department of the Interior, Bureau of Land Management, Nesting
Habitats and Surveying Techniques for Common Western Raptors, Technical Note 316, 1978.
U.S. Department of the Interior, Bureau of Land Management, Visual Resource Management Program, U.S. Government Printing Office, 1980.
U.S. Department of the Interior, Fish and Wildlife Service, Rehabilitation of Western Wildlife Habitat, U.S. Government Printing Office.
U.S. Department of the Interior, Geological Survey, Geology of the Eldorado Springs Quadrangle, Boulder and Jefferson Counties, Colorado, Geological survey Bulletin 1221-D, 1967.
U.S. Department of the Interior, Geological Survey, Miscellaneous Investigations series:
Geologic Map of the Boulder-Fort Collins-Greeley Area, Colorado,
Map I-855-G, 1978
Geologic Map of the Greater Denver Area, Front Range Urban Corridor, Colorado, Map I-856-H, 1979.
Landforms in the Boulder-Fort Collins-Greeley Area, Front Range Urban Corridor, Colorado, Map I-855-H, 1978.
Map Showing Potential Gravel Sources and Crushed Rock Aggregate in the Greater Denver Area, Front Range Corridor, Colorado,
Map I-856-A, 1974
Reconnaissance Map Showing Relative Amounts of Soil and Bedrock in the Mountainous Part of the Eldorado Springs Quadrangle, Boulder and Jefferson Counties, Colorado, Map MF-695, 1975.
Vegetation in the Greater Denver Area, Front Range Urban Corridor, Colorado, Map I-856-I, 1979.
American Society of Landscape Architects Landscape Architecture Technical Information Series Vol. 1, No. 3, "Creating Land for Tomorrow". 1978.
Boulder County Sand and Gravel Producers Rules and Regulations. 1978.
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Colorado Mined Land Reclamation Board Rules and Regulations. 1978.
High Altitude Revegetation Committee Proceedings : High Altitude Revegetation Workshop No. 3. 1978, p. 162-170.
Madole, Richard F. Environmental Inventory and Land Use Recommendations for Boulder County, Colorado. Boulder, CO: Institute of Arctic and Alpine Research, University of Colorado, 1973.
THK Associates Summary Report: South Table Mountain Aggregate Development. Denver, CO, 1980.