Ken Mitchell Open Space Master Plan

City of Brighton, Colorado

Shalkey & Team, Inc. ERO Resources Corp Icon Engineering, Inc.

October, 2006 Acknowledgements Ken Mitchell Open Space Master Plan

This Master Plan was commissioned to the consulting landscape architecture and planning firm of Shalkey & Team, Inc., by the City of Brighton on September 23, 2005, and submitted complete to the City on October 31, 2006. Sub-consultants ERO Resources Corporation and Icon Engineering, Inc., assisted Shalkey & Team with project planning.

In addition to Brighton City Council and Park and Recreation Advisory Boards, the planning team consisted of the following Brighton City Staff:

John Bramble, City Manager Gary Wardle, Director of Parks and Recreation Mark Heidt, Assistant Director, Department of Parks and Recreation Terry Benton, Director of Public Works Dawn Hessheimer, Department of Public Works Water Specialist

Respectfully Submitted: Edward J. Shalkey, President Shalkey & Team, Inc. 820 16th St., Denver, CO, 80202, (303) 820-3340

i Table of Contents Ken Mitchell Open Space Master Plan

I. INTRODUCTION Overview of the Physical Resource...... 1 Map No. 1 - Overview...... 2 Overview of the Planning Program ...... 3

II. PLANNING PROGRAM ...... 5 Preliminary Program ...... 5 Final Program ...... 5

III. SITE INVENTORY...... 6 Map No. 2 - Aerial Photograph ...... 7 Map No. 3 - Topographic Map ...... 8 Map No. 4 - Regional Context ...... 9 Map No. 5 - Land Ownership ...... 10 Map No. 6 - Natural Resources...... 11 Natural Resources Site Review ...... 12 Map No. 7 - Existing Utilities ...... 19 Map No. 8 - Proposed Water Management Improvements...... 20 Map No. 9 - Urban Drainage and Flood Control District Projects ...... 21

IV. MASTER SITE DEVELOPMENT PLAN ...... 22 Graphic No. 1 - Master Site Development Plan ...... 23 Graphic No. 2 - Southeast Corner Enlargement ...... 24 Figure No. 1 - Band Shell Concept ...... 25 Figure No. 2 - Paintball Field Concept ...... 25 Graphic No. 3 - Beach and Grand Pier Enlargement ...... 26 Figure No. 3 - Grand Fishing Access Pier Concept ...... 27 Graphic No. 4 - Grand Fishing Access Pier Enlargement...... 28 Figure No. 4 - Ken Mitchell Park Site Concept ...... 29 Figure No. 5 - Pump House Concept ...... 29

V. RECORD OF PUBLIC PROCESS ...... 30 Figure No. 6 - Overflow Culvert Concept...... 33

VI. COST ESTIMATE...... 33 Map No. 10 - Cost Estimating Areas...... 34

ii I. INTRODUCTION

Overview of the Physical Resource: The Ken Mitchell Open Space Planning Area consists generally of a combination of four future, currently active and recently depleted gravel mining quarry cells; a total of approximately 607 acres of publicly and privately owned land and water resource. Land currently under the City’s control, including Cells No. 1, 2 and 3, Ken Mitchell Park and the quarry operator’s yard, total approximately 434 acres, 170 acres of which will be water when all proposed water storage cells are full.

The Ken Mitchell Open Space Planning Area is generally located east of the South Platte River (the Platte forms the western boundary of the project), south of Colorado Highway 7, north of 144th Ave, and west of Brighton Road. Practically the entire planning area, except for the gravel operation’s quarry yard lies within the 100 year floodplain.

See Map No.1, Overview, next page.

Configuration of Land and Water: Three of the gravel mining cells, and the operator’s quarry yard were acquired by the City of Brighton in 1988 for the dual purpose of augmentation of water storage and public access open space. The City has a First Right of Refusal agreement in place to purchase Erger’s Cell for the same purposes when it is depleted.

Quarry Cells No. 1, and No. 2 are depleted of gravel and are in various stages of engineering preparation by the City of Brighton for water storage purposes. A land bridge separates a portion of the east side of Cell No 1. from the west side. This land bridge will remain in place to facilitate a conveyor belt until the quarry operator depletes Erger’s Cell (10 to 20 years), then it will be removed. Cell No. 3 is currently being mined and also expected to be in operation for another 10 to 20 years. Erger’s Cell is being prepared for mining activities at the time of this writing.

Characterization of the Water Storage Cells: The existing and planned gravel quarry cells will be utilized by the City to store water for augmentation purposes. This means significant draw-downs in stored water elevations whenever the City needs to release water to the South Platte River to satisfy water calls from water users with more senior rights than the City. Other similar City reservoirs have been known to almost completely empty or refill their stored volume in a matter of a few weeks. The combined practicality of most efficient mining operations and most efficient water storage mean the edges of the storage cells, when completed, will be configured of steep (mostly between 2:1 and 3:1) slopes. The south to north sloping gradient of the South Platte River means that the maximum water level in each cell will be about 3 ft. lower than the cell adjacent to it on the south.

The water storage function of these four cells will require that each cell be connected to the adjacent cell with a spillway (for flood events), and culverts (for normal high water movement). Each cell will be connected to the South Platte River with a spillway so that water can be safely managed into and out of the cells during flood events. The four cells will be supplied via the proposed 144th Avenue Augmentation Pipeline Project and two pumping stations between the South Platte River and Cells No. 1 and No. 3. A pumping station and outlet tower at the northwest corner of Cell No. 1 will facilitate water flows from the storage cells back to the South Platte River.

1 Map No. 1 - Overview

2 The Urban Drainage and Flood Control District (UDFCD) have plans to construct several streambank stabilization projects and a drop structure project on the reach of the South Platte River adjacent to the project study area.

The land bridge between Cells No. 2 and No. 3 contains a gas line easement, and has been proposed by UDFCD as a conveyance corridor for the base flow of Third Creek (flood flows would be routed into Cells No. 2 and/or No. 3) between the east side of the project study area and the South Platte River.

Existing Gas Well: An existing gas well, with a storage tank surrounded by chain link fence, exists on the west side of Cell 1, between the west edge of the cell and the South Platte River. Maintenance access by the well owner (or their representative) needs to be maintained to this well.

Other Lands in the Study Area: The gravel mine operator maintains approximately 20 acres of yard space, including material stockpiles, screens, scales and similar mining equipment and installations.

Existing City Recreational Improvements: The City of Brighton maintains two existing improvements and a trail along the northeast border of the project study area. The South Platte River Trailhead is a modest parking facility with an informational kiosk, which accesses a section of concrete hiking trail leading out of the project study area to the north. This trail segment, when joined to a future trail leading to the south through the Adams County Regional Park, will complete an important missing link in the Colorado Front Range Trail. Just south of the South Platte River Trailhead facility and adjacent to Cell 1 is the existing Ken Mitchell Park. This is approximately a 8 acre, linear neighborhood park with a small asphalt parking area, a modest playground, a multi-purpose irrigated turf field, an asphalt basketball court and a few picnic tables and grills located in a sparse bosque of juvenile shade trees.

More detailed inventory and analysis of the planning area’s physical resources is included in Section III.

Overview of the Planning Program:

A strong programming philosophy emerged during the public consensus building process associated with project planning. This philosophy was a result of a series of insightful comments from the public (mostly neighborhood), City Parks and Public Works staff, City Council and the Parks and Recreation Advisory Board. The general consensus which lead to the program for development discussed in Section II consisted of the following governing elements:

Water Storage: The augmentation water management requirements of the project are relatively rigid, and so will be the function and placement of the necessary public works improvements needed to facilitate management (spillways, culverts, pump houses, etc.), but there may be considerably more flexibility in managing the appearance of these structures. The storage cell lakes will resemble cereal bowls more than natural bodies of water, and the lake levels are anticipated to fluctuate considerably on a seasonal basis. The planning team was properly advised to resist the urge to turn the storage cells into amusement sites, in favor of preserving them passively as they are; large scale natural resource deposits, imperfections and all.

3 Because of the dangerous configuration of the edges of the storage cells (3:1 or steeper), and the fluctuating water levels, human contact with the water resource should be limited to fishing from the shore or from piers, and non-motorized boating.

Much Water, Little Land: The location and configuration of the storage cell lakes, with little land separating one cell from another and each cell from the site’s property line in most locations, will result in much water surface and com- paratively little land to support access to the water. And, the land resource remaining available around the margins of the storage cell lakes will be unusually thin and linear in configuration. For this reason, the consultant recommends the acquision of additional land resources contiguous to the planning area as such land may become available.

Recreation vs. Conservation: Even though environmental inventory and analysis revealed the site to be relatively barren from a habitat and wildlife population point of view, some portions of the planning area are obviously more natural than others, and those areas should be preserved from recreational development.

The western margin of the planning area, between the western edges of the cells and the South Platte River is the least disturbed portion of the planning area. While few species of wildlife are at home here, many pass through to and from their home habitat north and south of the planning area. The western margin along the South Platte River, all agreed, should be conserved as a natural area. Another potential (wetlands) conservation area exists along the floodplain of Third Creek, south of the gravel mine operator’s quarry yard.

The existing Ken Mitchell Park, and the gravel mine operator’s quarry yard, and the adjacent lands between these areas and Cells No. 2 and 3 were recommended for the more active recreational develop- ments proposed for the project. The land massing configuration of this area, it’s already highly disturbed condition, and the potential for utility and roadway access to the Brighton Road corridor make this portion of the planning area more conducive to active use development.

Ken Mitchell Park: The existing park should remain as a neighborhood facility, but it’s relatively spartan, developer-built facilities should be upgraded to the City’s current standards for similar neighborhood parks, and better advantage should be taken of the Cell No. 1 water resource (actually the edge thereof) adjacent to the west side of the park.

Trails: The project should connect the segment of the Colorado Front Range Trail existing north of the South Platte River Trailhead south through the planning area to join Adams County’s segment of the Front Range Trail, currently advancing to the north from the Adams County Regional Park. The Front Range Trail segment should be connected to trail loops around each of the storage cells for the multiple purposes of maintenance, safety and recreational access.

4 II. PLANNING PROGRAM

The planning team began the programming phase with a brainstormed list of all of the potential facilities and activities that could be collectively imagined for the planning area. This initial list consisted of the following elements:

Preliminary Program: 1. Vehicular Access and Parking 12. Snack Shop/Restaurant 23. Float Fishing 2. Trails 13. Reservable Picnic Meadows 24. Diving 3. Visitor Center 14. Family/Individual 25. Radio Control Boating 4. Wildlife Viewing Picnic Meadows 26. Water Skiing 5. Swimming and/or 15. Canoeing 27. Paintball Sunning Beach 16. Sailing 28. Water Polo 6. Wave Pools & Slides 17. Paddle Boating 29. Amphitheatre 7. Interactive Water Toys 18. Rowing/Sculling 30. Dog Off-Leash Area 8. Sand Volleyball 19. Ice Skating 31. Festival/Event/ 9. Boardwalk 20. Ice Sailing Gathering Space 10. Playgrounds 21. Ice Fishing 32. Art Program 11. Picnic Pavilions 22. Shore Fishing 33. Rope Course

Through the course of design team, general public, Parks Board and City Council meetings designed to strengthen and refine the program (see Section V - Summary of Public Process), a number of the initially proposed elements were eliminated from consideration and others modified. By the end of the programming process, and after a few master site plan alternatives were developed and discussed, the final project program evolved as follows:

Final Program:

Terrestrial Elements (of the land): 1. Vehicular Access and Parking: A. From Brighton Road east of the mine operator’s quarry yard, with parking generally east of Cells No. 2 and No. 3, and south of Cell No. 1 B. To the existing Ken Mitchell Park (requires additional parking only) C. The South Platte River Trailhead (no improvements required) 2. Trails: A. South Platte River Trail between the southeast corner of the planning area to the South Platte River Trailhead B. Loop maintenance and recreational trails around each storage cell – limit public access in habitat sensitive areas C. Interpretive trail 3. Wildlife Habitat Enhancement Areas; Concentrate habitat improvements along South Platte River corridor 4. Nature Center; Develop synoptic wetlands garden from water quality enhancement basin for Third Creek drainage just east of Cell No. 3. 5. Picnic Meadows; Including pavilions, rest rooms, drinking fountains, etc. 6. Amphitheatre: With bandshell, for large community-scale concerts, gatherings 7. Frisbee Golf Course; Site in combination with other facilities, such as Picnic Grounds

5 8. Paintball Area; Develop a “concept field” layout in the area of the mine operator’s quarry yard 9. Dog-off Leash Area(s); Develop one large, community scale facility near the mine operator’s quarry yard, and another neighborhood scale facility near Ken Mitchell Park 10. Festival/Event/Gathering Space; Consisting of a large open area (a la great lawn) with good access to Brighton Road and generous parking 11 Skatepark; A community scale facility in the area of the mine operator’s quarry yard 12. General Revegetation Throughout; Consisting primarily of re-establishing native grasses, forbs, shrubs and tree populations over the large portions of the planning area disturbed by mining activities

Aquatic Elements (of the lakes): 13. Sunning Beach; A south facing, sandy expanse adjacent to, but separated by fencing from (swimming in the lake should not be allowed) one of the storage cells 14. Boardwalk(s); Promenade space placed strategically at the edge of some of the storage cells, improved with traditional wooden or other “hardscape” decks with appropriate lighting and fur- nishings 15. Fish Habitat Enhancement Areas; Strategically place in order to encourage fishing at limited access points along storage cell shores where fishing safety improvements can be concentrated 16. Shore Fishing Access Points; In concert with Fish Habitat Enhancement Areas, provide limited access points along storage cell shores where fishing access safety improvements such as floating or fixed piers, boardwalks, etc., can be constructed. All other reaches of storage cell shoreline should be posted, fenced and/or planted with drifts of thorny shrubs. 17. Grand Fishing Pier; One pier should be developed into approximately the center of Cell No.1 for the multiple purposes of boating, fishing, scenic and water quality monitoring access purposes.

Storm and Augmentation Water Management Improvements: 18. Proposed Riverbank Stabilization improvements at several points along the South Platte River (by UDFCD) 19. A proposed South Platte River Drop Structure improvement (by UDFCD) 20. A (2 yr) Storm Outlet Channel for third creek on the land bridge between Cells No. 2 and No. 3 (by UDFCD) 21. Spillways from Lakes to the Platte on each of the four cells in the planning area 22. Slurry Walls around each storage cell (Cell No. 1 is already completed) 23. Spillways and Overflow Culverts connecting each storage cell to it’s adjacent neighbor (3 spillways total) 24. Maintenance Access to the perimeter of all cells 25. Inlet Pumping Stations between the Platte and Cells No. 1 and No. 3 25. Outlet Pumping Station and outlet tower between Cell No. 1 and South Platte River 26. 144th Avenue Augmentation Pipeline Project

III. SITE INVENTORY

The Design Team undertook aerial photography and topographic mapping of the planning area, along with a general site inventory; mapping for which is included on the following pages.

6 Map No. 2 - Aerial Photograph Date of Photography - September 2005 7 Map No. 3 - Topographic Map Date of Photogrammetry - August 2005 8 Map No. 4 - Regional Context

9 Map No. 5 - Land Ownership

10 Map No. 6 - Natural Resources

11 Natural Resources Site Review:

ERO Resources Corporation has visited the site and prepared a thorough natural resource review, including potential wetlands, identiﬁ cation of potential threatened and endangered species habitat, and identiﬁ cation of other natural resources that might affect or be affected by planning. Jurisdictional wetland delineations were not conducted during this site review.

General:

Ken Mitchell Open Space is located along the South Platte River. In the vicinity of the open space area, much of the land is either under cultivation or is being mined for sand and gravel. Numerous lakes have been created from depleted gravel mines. The habitat provided by the South Platte River, the lakes, and agricultural ﬁ elds supports a variety of waterfowl and wildlife, but habitat is being lost as residential and commercial development encroaches into agricultural lands on both sides of the South Platte River.

Because of the past and current disturbance associated with agriculture and mining, much of the land in the open space area is disturbed. Native plant communities have been replaced with communities composed entirely of non-native species and communities with a mix of native and non-native species. In some area, vegetation is completely lacking.

Riparian vegetation along the South Platte River includes areas of mixed shrubs that include sandbar willow (Salix exigua) with an upland herbaceous understory dominated by smooth brome (Bromopsis inermis), a non-native pasture grass. Some shrub areas along the South Platte include small patches of snowberry (Symphoricarpos occidentalis). Stands of plains cottonwood (Populus deltoides) are also present along the South Platte River. These forested riparian areas typically have an understory of non- native grasses with occasional clumps of snowberry. Immediately adjacent to the South Platte River, there are wetlands dominated by dense reed canarygrass (Phalaroides arundinacea), a non-native species, and sandbar willow. The wetlands are present in narrow margins along the river banks and on stabilized, but periodically inundated, sandbars. Riparian shrubs and wetlands are also present in a narrow margin around the eastern portion of previously mined Cell No. 1, which is currently ﬁ lled with water.

Many disturbed, upland areas away from the South Platte River are dominated by weedy non-native species such as kochia (Kochia scoparia), knapweed (Acosta diffusa), and Canada thistle (Cirsiumarvense). Areas dominated by these species tend to be monocultures with a high percentage of bare sand and gravel. Other upland areas are mixed grasslands dominated by smooth brome with a mix of non-native species such as knapweed. Areas with mixed grasslands have typically not been affected by gravel mining.

The quality of most of the vegetation communities in the open space area is low because of the prevalence of weedy non-native species and the large areas of bare ground. The riparian and wetland communities along the South Platte River have the highest quality, but even these have been disturbed in the past and are dominated by non-native species.

Potential Wetlands and Waters of the U.S.:

The Clean Water Act was passed by the U.S. Congress in 1977 to protect the physical, biological, and chemical quality of waters of the U.S. The U.S. Army Corps of Engineers’ (Corps) Regulatory Program administers and enforces Section 404 of the Clean Water Act. Under Section 404, a Corps permit is

12 required for the discharge of dredged or fi ll material into wetlands and waters of the U.S. The Corps defi nes waters of the U.S. as all navigable waters and their tributaries, all interstate waters and their tributaries, all wetlands adjacent to these waters, and all impoundments of these waters. Because of court challenges to the Corps’ jurisdiction over wetlands and waters of the U.S., the Corps regulatory guidance is in a state of fl ux. For example, as a result of the 2001 ruling by the Supreme Court in the matter of Solid Waste Agency of Northern Cook County vs. U.S. Army Corps of Engineers, No. 99-1179 (January 9, 2001), the Corps’ regulatory jurisdiction over isolated, non-navigable, intrastate waters has been eliminated if the sole nexus to interstate commerce was use of the waters by migratory birds. The Corps continues to develop its guidance for the Section 404 regulatory program.

The project area was assessed for wetlands and potential waters of the U.S. The South Platte River and its adjacent wetlands have previously been determined by the Corps to be jurisdictional waters of the U.S. The Corps has also previously determined that McCann Ditch (along the north east edge of the open space) is a jurisdictional water of the U.S. It is possible that the wetlands around the margin of the existing lake are jurisdictional waters of the U.S. because they are adjacent to McCann Ditch.

If activities, such as the construction of stormwater outfall structures, recreation facilities, or habitat enhancement would require placing dredged or ﬁ ll material in wetlands or below the ordinary high water mark of the South Platte River or the existing lake, Section 404 authorization from the Corps may be required. Prior to disturbance, wetlands associated with the South Platte River and the lake that may be impacted by project activities should be delineated following the 1987 Corps of Engineers Wetland Delineation Manual and the subsequent ﬁ ndings submitted to the Corps for its approval. Wetland delineations are typically valid for 5 years unless new information warrants an update to the delineation.

Threatened, Endangered and Candidate Species: The project area was assessed for potential habitat for threatened, endangered, and candidate species under the Endangered Species Act (ESA). Federally threatened and endangered species are protected under the Endangered Species Act of 1973 as amended (16 U.S.C. 1531 et seq.). Signiﬁ cant adverse effects to a federally listed species or its habitat require consultation with the U.S. Fish and Wildlife Service (Service) under Section 7 or 10 of the ESA. The Service lists several threatened and endangered species with potential habitat in Adams County:

See Table on Following Page

There is no likelihood for the proposed project to directly affect the black-footed ferret, Preble’s meadow jumping mouse, or Mexican spotted owl. The open space is in block clearance zones for the ferret and mouse and there is no suitable habitat for the owl. The interior least tern, piping plover, whooping crane, and pallid sturgeon are South Platte River species that are affected by depletions of the South Platte River. Impacts on these species must be evaluated if any depletions of the South Platte River would occur due to project activities, including water storage. Using the gravel mines as water storage facilities may result in depletions of the South Platte River, however, any depletions would be addressed during design of the water storage facilities. Implementation of the recreation master plan would not result in depletions of the South Platte River and so would not affect on the South Platte River species.

Because of the association of the Preble’s meadow jumping mouse, bald eagle, and Ute ladies’-tresses orchid to wetland/riparian habitat, potentially suitable habitat is more likely to occur within development sites across the Front Range. Because these species are more likely to be addressed by regulatory agencies

13 such as the U.S. Army Corps of Engineers, a more detailed discussion is provided below.

Preble’s Meadow Jumping Mouse: A. Species Background: On May 13, 1998, the Preble’s meadow jumping mouse was listed as threatened under the ESA. Typically, Preble’s meadow jumping mouse is located in low undergrowth consisting of grasses and forbs, in open wet meadows, riparian corridors near forests, or where tall shrubs and low trees provide adequate cover. Along Colorado’s Front Range, the mouse is found below 7,500 feet in elevation, generally in lowlands with medium to high moisture along permanent or intermittent streams.

In December 2003, the Service received two petitions (State of Wyoming’s Ofﬁ ce of the Governor and Coloradans for Water Conservation and Development) to delist Preble’s based on new information on species taxonomy. On March 31, 2004, the Service determined that these petitions and new biological information on the species indicated that delisting may be warranted and initiated a status review.

After a complete review of the petitions to remove Preble’s from the endangered species list,

14 the Service determined that the action is warranted and has begun the process to formally delist Preble’s. This action was based on new research that indicates that Preble’s should not be classiﬁ ed as a separate subspecies of meadow jumping mouse; however, the Service continues to review new data, which may delay any decision to delist the mouse. Until the Service makes a ﬁ nal determination, Preble’s will continue to be protected under the Endangered Species Act.

B. Potential Habitat and Possible Effects: The project area was assessed for potential Preble’s habitat. Although potential habitat occurs along the South Platte River, the project area is within an area designated by the Service as the Preble’s Denver metro block clearance zone. In designating a block clearance zone, the Service eliminated the need for individuals or agencies to coordinate with the Service prior to conducting activities in habitats that otherwise would be deemed to have potential to support Preble’s (Carlson 2000). The block clearance zone has been updated and renewed until 2007 (Linner 2004).

Bald Eagle: A. Species Background: The bald eagle is a large North American bird with a historical distribution throughout most of the U.S. The bald eagle was listed as an endangered species in 1978. Population declines are attributed to habitat loss, the use of organochlorine pesticides, and mortality from shooting. Since its listing, the population trend for the bald eagle has been increasing. The bald eagle was downlisted from endangered to threatened in 1995 and the Service is proposing to delist the bald eagle due to population recovery. If the bald eagle is removed from the list of threatened and endangered species, it will continue to be protected under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act.

Bald eagles are primarily winter residents in Colorado, although nesting along the Colorado Front Range has increased in recent years. Most nesting in Colorado occurs near lakes or reservoirs or along rivers. Typical bald eagle nesting habitat consists of forests or wooded areas that contain many tall, aged, dying, and dead trees (Martell 1992).

B. Potential Habitat and Possible Effects: The project area was assessed for potential bald eagle habitat. No designated critical or essential eagle habitat would be impacted by the proposed project, but bald eagles are known to frequent the South Platte River in the vicinity of the open space area. Although unlikely because too few large, old cottonwood trees are present, it is possible that eagles could nest or roost in the forested riparian areas along the South Platte River. Bald eagles are known to perch occasionally in the trees. As gravel mining ends and the water storage facilities are ﬁ lled, bald eagles may forage more frequently for ﬁ sh in the open space area. Conversely, recreation use of the area, especially in warm months, may discourage bald eagle use.

Operation of the water storage facilities and recreation use of the open space is not likely to have an adverse effect on bald eagle because bald eagles do not currently use the area other than for occasional perching. The water storage could have a beneﬁ cial effect on bald eagle by increasing prey availability.

15 Ute Ladies’-Tresses Orchid A. Species Background Ute ladies’-tresses orchid (orchid) occurs at elevations below 6,500 feet in moist to wet alluvial meadows, ﬂ oodplains of perennial streams, and around springs and lakes. Occurrences of the orchid have been documented in Colorado, Wyoming, Idaho, Nevada, and Utah. Once thought to be fairly common in low elevation riparian areas in Colorado, Utah, and Nevada, currently only sixteen populations are reported to occur in Colorado with most populations occurring along the Front Range. Generally, the vegetative cover is relatively open; dense, overgrown sites are not conducive to orchid establishment. Where the orchid is found, soils are typically alluvial deposits of sandy, gravelly material that are saturated to within 18 inches of the surface for at least part of the growing season.

B. Potential Habitat and Possible Effects Potential habitat for the orchid is present along the South Platte River, but dense vegetation likely precludes the orchid from being present. In the event vegetation along the South Platte River would be disturbed as part of implementing the recreation master plan, a full habitat assessment, and possibly a presence/absence survey, should be done.

Other Species of Concern: Raptors and Migratory Birds: Most bird species are protected under the Migratory Bird Treaty Act (MBTA), which protects migratory birds as well as their nests. With the exception of house sparrow (Passer domesticus), rock dove (common or feral pigeon) (Columbia livia), and European starling (Sturnus vulgaris), all wild birds commonly found in the U.S. are protected by the MBTA, even species that tend to be present throughout the year such as magpie and great horned owl. All nests are protected, including cavity nests (e.g., ﬂ icker), ground nests (e.g. killdeer), and subterranean nests (e.g., burrowing owl).

The MBTA does not contain any prohibition that applies to the destruction of a bird nest alone (without birds or eggs), provided that no possession occurs during the destruction. While destruction of a nest by itself is not prohibited under the MBTA, nest destruction that results in the unpermitted take of migratory birds or their eggs is illegal and fully prosecutable under the MBTA (Migratory Bird Permit Memorandum, U.S. Fish and Wildlife April 15, 2003).

Under the MBTA, the Service may issue nest depredation permits, which allow a permittee to remove an active nest. The Service, however, issues few permits and only under speciﬁ c circumstance usually related to human health and safety. Obtaining a nest depredation permit is unlikely and is a process that takes from four to eight weeks. The best way to avoid a violation of the MBTA is to remove vegetation outside of the active breeding season, which typically falls between March and August, depending on species. Public awareness of the MBTA has grown in recent years, and most MBTA enforcement actions are the result of a concerned member of the community reporting a violation.

The riparian vegetation along the South Platte River provides potential nesting habitat for many migratory bird species. Currently, great blue herons have built about 40 nests in a heronry along the South Platte River. Two raptor nests are also present along the South Platte River. Because of their proximity to each other, only one raptor nest would be active in each breeding season. It is likely that many songbird nests are also present in the trees and shrubs along the river and along McCann Ditch. Most of the uplands in the

16 open space area are sparsely vegetated and weedy and provide little nesting habitat for migratory birds.

In order to avoid disturbing nesting birds or destroying active nests, vegetation should be removed from the site outside of the breeding season. If an active nest is identiﬁ ed within or near the project area, activities that would directly impact the nest or that would encroach close enough to cause adult birds to abandon the nest during the breeding season should be restricted. The Ken Mitchell master plan will include provisions to buffer the heronry from disturbance by recreation activities. Prior to construction activities, the raptor nests will be surveyed to determine if they are active. If active, the Colorado Division of Wildlife recommends that no new activities take place within ¼ to ½ mile of the active nest, depending on the species. Activities in the vicinity of the nest can occur any time during the non-nesting season.

Black-Tailed Prairie Dog A. Species Background: Black-tailed prairie dogs (Cynomys ludovicianus) are social animals that occur in colonies or “towns” formed by a series of burrows. Species such as black-footed ferret (Mustela nigripes), burrowing owl (Athene cunicularia), prairie rattlesnake (Crotalus viridis), and mountain plover (Charadrius montanus) are closely linked to prairie dog burrow systems for food and/or cover. Prairie dogs provide an important prey resource for numerous predators including badger, coyote, fox, golden eagle, ferruginous hawk and other raptors.

In 1998, the Service received a petition from the National Wildlife Federation to list the black- tailed prairie dog as a threatened species under the ESA. In the February 4, 2000 Federal Register, the Service announced that listing of the black-tailed prairie dog under the ESA is warranted but precluded by other higher priority actions. After several years of research and with new information on population levels, the Service has removed the black tailed prairie dog as a candidate species from the Endangered Species list (August 12, 2004 Federal Register). Prairie dogs are still a noteworthy wildlife species because of their prevalence across the Front Range and because of associated species such as burrowing owls, a species protected by the Migratory Bird Treaty Act.

B. Potential Habitat and Possible Effects Black-tailed prairie dogs are present along the south edge of the open space area. Gravel mining is planned in this area, so the colony will likely be eliminated in the future. If black-tailed prairie dogs are present in areas of open space that will be disturbed during implementation of the master plan and must be removed, removal should be conducted as humanely as possible by removing or exterminating them prior to any earthwork. If black-tailed prairie dog removal is scheduled between March 1 and October 31, the time when burrowing owls are in Colorado, the colony should be surveyed for burrowing owls to ensure compliance with the MBTA.

Other Wildlife Although degraded by past disturbance from mining and agriculture, the wetland and riparian habitat along the South Platte River provides important habitat to many species found along the Front Range including raptors, songbirds, mule deer, small mammals, and other species. Following implementation of the master plan, the open space area will continue to provide important habitat for wildlife. As areas in the vicinity of the open space area are developed, wildlife species sensitive to human disturbance may decline in abundance or abandon the area, while other wildlife species adapted to human presence are likely to increase in abundance. Species that may decline would include mule deer, some raptors, and possibly coyotes. Species likely to increase would include red fox, raccoon, and great horned owl.

17 Overall, surrounding and continuing development contributes to a decline in the number and diversity of wildlife species nearby and to a change in species composition to favor species that adapt better to human disturbance.

An important component of the master plan will be to preserve, enhance, and create wildlife habitat. The lakes will provide extensive habitat for waterfowl and fi sh. In addition to the open water itself, the lakes will include habitat enhancing features such as submerged trees that create shelter areas for fi sh; shallow benches along reaches of the shoreline that provide foraging areas for dabbling waterfowl, fi sh, and herons; islands or fl oating platforms that provide resting places for waterfowl; and perches for bald eagle made of large dead trees or telephone poles. Although nesting herons are typically tolerant of human encroachment, buffers will be established during the nesting season that will restrict human encroachment to minimize disturbance to the heronry. Riparian vegetation along the South Platte River will be preserved and enhanced to provide shelter, forage, and movement corridors for wildlife. Enhancements will include using native species in all restoration activities, maintaining healthy stands of shrubs and cottonwoods by replacing dead or dying stands, and coordinating with Urban Drainage and Flood Control District to ensure District projects provide maximum habitat benefi ts. Active recreation will be located away from the South Platte River in areas closer to existing and future development.

Summary Currently, most of the proposed Ken Mitchell Open Space is degraded by mining activities. Additional areas will be mined in the future, further degrading the area. The implementation of the Ken Mitchell Open Space master plan is unlikely to have any effect on threatened or endangered species, but a detailed habitat assessment may be necessary for Ute ladies’-tresses orchid and the locations of bald eagle nests and roost sites should be conﬁ rmed prior to construction of recreation facilities along the South Platte River.

There are no unique biological resources in the open space area. The most ecologically important resource is the South Platte River riparian corridor. Most of the corridor in Adams and Weld counties has been encroached upon by mining and agricultural activities. Despite the encroachment and impacts from grazing, the corridor supports a variety of wildlife and will continue to do so following implementation of the Ken Mitchell Open Space master plan. Lakes eventually resulting from mining and implementation of the master plan, including enhancements to the riparian corridor, will improve the quality of wildlife habitat.

References: Carlson, LeRoy. 2000. Colorado Field Supervisor, Colorado Field Ofﬁ ce, United States Fish and Wildlife Service. Letter to Steve Dougherty, July 17.

Linner, Susan C. 2004. Colorado Field Supervisor, Colorado Field Ofﬁ ce, United States Fish and Wildlife Service. Letter to Mark Hunter, January 27, 2004. Martell, M. 1992. Bald Eagle Winter management guidelines. USFWS, Reg. 3, Minneapolis, MN.

Martell, M. 1992. Bald Eagle Winter management guidelines. USFWS, Reg. 3, Minneapolis, MN.

U.S. Fish and Wildlife Service. 2005. Federally Listed and Proposed, Endangered, Threatened, Experimental, and Candidate Species and Habitat in Colorado by County. http://www.r6.fws. gov/endspp.County Lists/COLORADO.htm

18 Maqp No. 7 - Existing Utilities

19 Map No. 8 - Proposed Water Management Improvements

20 Map No. 9 - Urban Drainage and Flood Control District Projects

21 IV. MASTER SITE DEVELOPMENT PLAN

See Graphic No.1, Master Site Development Plan, next page.

Vehicular Access and Parking: There will be only three public access portals to the open space for motorists. The principal point of public access should be from Brighton Road, in the area of the mine operator’s current access road, just southeast of the quarry yard. Most public parking should also occur in the area of the quarry yard and the east and north sides of Cell No. 2. The master site plan provides for approximately 275 parking spaces for the Swimming Beach/Grand Fishing Pier area, 239 for the Great Lawn/Nature Center area, 145 for the Picnic Meadows/Skatepark/Dog Off-Leash area, and approximately 42 for the Paintball Area, for a total of approximately 700 spaces.

City right of way on the alignment of 148th Avenue could be used as temporary access into the site, until such time as the quarry yard becomes available for open space development.

Public access to the existing (or improved) Ken Mitchell Park site should occur via it’s current configuration. The existing parking lot should be expanded (approximately 57 spaces shown), but not to the extent that traffic from outside of the immediate neighborhood is overly encouraged – the more parking available here, the more the park will tend to be utilized by visitors outside of the neighborhood.

The existing South Platte River Trailhead facility should be maintained and should be adequate for access to the Front Range Trail in it’s current configuration and location.

Trails: The Front Range Trail should enter the planning area from the south, just east of the South Platte River, extend north from that point along the Platte, then should cross the planning area to the east via the land bridge between Cells No. 1 and 2., thence to the north along the east side of the planning area through Ken Mitchell Park to the South Platte River Trailhead.

Each of the four water storage cells are to be provided with a looped maintenance and access trail around them, with the exception of Erger’s Cell, where for wildlife habitat protection purposes, the west and the north sides of the cell should be limited to maintenance access only. The Front Range trail segment should be paved, all other trail segments can be “mineral surfaced” (unpaved) unless occurring in more active use areas where paving may be appropriate.

Any of the project’s trails discussed above may host interpretive sites. It is anticipated that as the Third Creek drainage basin continues to urbanize and becomes subject to increasing flood flows, a wetlands type water quality basin may be created between the northeast corner of Cell No. 3 and Brighton Road. This area could become a synoptic wetlands garden, with an associated interpretive trail for controlled educational purposes.

Wildlife Enhancement Areas: Revegetation of all areas disturbed by mining activities will greatly enhance the overall habitat value of the planning area. The plan establishes the entire length of the South Platte River corridor between the river and the water storage cells as a wildlife habitat corridor and intends to limit access to the west and north sides of Erger’s Cell to maintenance activities only. Habitat improvements should occur in these areas, and also in the Third Creek Water Quality Wetlands proposed just east

22 Graphic No. 1 - Master Site Development Plan

23 of Cell No. 3.

Nature Center; Consisting of an interpretive trail skirting the edge of a wetlands type water quality enhancement basin for the Third Creek drainage just east of Cell No. 3, including a shelter (non-habitable building) with interpretive exhibits

Picnic Meadows; Three large picnic meadows are provided for in the area of the mine operator’s quarry yard (Meadows A, B, and C). Picnic Meadow A is proposed to be a non-reservable family oriented picnic meadow, and Meadows B and C set up for large reservable groups, although B and C are also suitable for family groups when not reserved.

Graphic No. 2 - South East Corner Enlargement

24 Amphitheatre: An amphitheatre is provided for at the west edge of the Great Lawn, at the southeast corner of Cell No. 3. The amphitheatre is anticipated to be a shallow topographic bowl oriented to the northwest, with a crescent shaped boardwalk at the edge of Cell No. 3, and a band shell (see Figure No. 1) incorporated into the boardwalk.

Figure No. 1 - Band Shell Concept

Frisbee Golf Course; Anticipated to be sited in combination with the Picnic Meadows

Paintball Area; This would be the type of facility called a “concept field” (see figure No. 2), consisting of a series of urban building and landscape constructions which are not as unattractive as other paintball field arrangements can be when they are not hosting competitions.

Figure No. 2 - Paintball Concept

25 Dog-off Leash Area(s); One large facility is provided for near the mine operator’s quarry yard, and another neighborhood-scale facility just north of Ken Mitchell Park

Festival/Event/Gathering Space; A 6 acre irrigated turf grass meadow is provided for, incorporating the amphitheatre at it’s northwest edge, along Cell No. 2. Parking for approximately 115 cars is provided nearby.

Skatepark; A community-scale facility in the area of the quarry yard, conveniently tucked against an existing concrete privacy fence separating the quarry yard from the residential neighborhood across 148th Ave., to the north.

Sunning Beach; The sunning beach would be about a 4 acre expanse of sand, with an attractive fence to prevent sun bathers from entering Cell No. 2 and becoming swimmers. An attractive alternative to access

Graphic No. 3 - Sunning Beach and Grand Pier Enlargement

26 to Cell No. 2 waters should be provided by, for example, a fairly large interactive water feature for water play as well as cooling purposes. A fourth Picnic Meadow is provided for on the opposite side of the Cell No. 1/Cell No. 2 land bridge from the sunning beach. Approximately 275 parking spaces are provided for the Sunning Beach, Picnic Meadow, and Grand Fishing Access Pier area.

Fishing Access Piers; A Grand Fishing Access Pier, approximately 1,200 ft. long, (see Figure No.3) is shown extending northward from the southeast corner of Cell No. 1. The pier should be developed with lighting, seating and a shelter at it’s end point. A marina of sorts, for mooring or launching of non-motorized water craft, could be developed utilizing the pier and/or the shore at the pier’s abutment.

Besides the Grand Fishing Access Pier, several additional, more modest fishing piers are shown extending from the edge of each water storage cell. Fishing from shore should be limited to boardwalks and fishing piers only. All other reaches of storage cell shoreline should be posted, fenced and/or planted with drifts of thorny shrubs.

Figure No. 3 - Grand Fishing Access Pier Fish Habitat Enhancement Areas; Because of steep the configuration of the storage cell walls, and the frequently fluctuating water levels, fish habitat enhancements will be difficult to achieve. It is therefore anticipated that energy invested in such improvements should happen in the areas of the fishing access points provided by piers and boardwalks shown on the plan.

27 Ken Mitchell Park Improvements; Access to the existing park will remain as existing, via Kinglet Ct, Mockingbird Street and Bromley Lane. The parking lot should be enlarged to approximately 57 spaces as shown. A new, ADA compliant playground, basketball court, restrooms, and shade structure should be developed. Access to the edge of Cell No. 1 should also be improved with a new boardwalk structure and fishing pier as shown in Figure No. 4. Fencing on the fishing pier and the boardwalk should be augmented with fencing north and south of the boardwalk to prevent neighborhood children (and adults) from free access to the storage cell shoreline.

Graphic No. 4 - Ken Mitchell Park Site Enlargement

28 Figure No. 4 - Ken Mitchell Park Site Concept

All of the Storm and Augmentation Water Management Improvements discussed in the planning program are shown on the plan in their approximate locations and extent. Because the purpose of this project is equal parts water augmentation and public access open space, it is recommended by the planning team that visible water works structures such as spillways, pump houses, overflow culverts and like improvements receive a level of architectural design well above what would be typical for a water augmentation project alone. As an example, see Figures No. 5 – Pump House Concept, and No 6 – Overflow Culvert Concept, for the level of architectural treatment recommended.

Figure No. 5 - Pump House Concept

29 V. RECORD OF PUBLIC PROCESS

Three Parks Board meetings, two public meetings, and one City Council meeting were held during the consensus building process for the Ken Mitchell Open Space Master Plan. These meetings were held as listed below:

A. Feb 1, 2006 – Parks Board (Programming Ideas) B. Mar 16, 2006 – Public Mtg. No 1 (Programming Ideas) C. Apr 12, 2006 – Public Mtg. No 2 (Reviewed Alternatives, Picked Preferred) D. May 3, 2006 – Parks Board (Picked Preferred Alternative w/ Modifications) E. Jun 7, 2006 – Parks Board (Accepted Modifications to Alt D) F. June 13, 2006 - City Council Study Session

City Parks Board and City Council Study Session meeting minutes are on record elsewhere in City archives – minutes of the two Public Meetings are reproduced below:

Ken Mitchell Open Space Public Meeting No. 1 March 16, 2006, 6:30 PM Meeting Summary

City staff and officials attending: Gary Wardle, Mark Heidt, Dawn Hessheimer, consultant Ed Shalkey, City Councilmen Wayne Scott and Daryl Meyers.

The meeting was opened by Gary Wardle, who made introductions and briefly explained the master planning process and schedule. Dawn Hessheimer made a brief summary of the project’s water storage func- tions. Ed Shalkey summarized the inventory of existing conditions and the potential program of activities for the site. The following public comments about program were recorded:

1. In addition to the larger loop and South Platte River Trails discussed, there should be shorter, bike and pedestrian trail loops and shorter trails to connect the neighborhood to the park and features inside of the park- one to another.

2. It was suggested that sand volleyball may be suited to areas along the South Platte River where sand is plentiful.

3. Participants hoped there would not be “too much” public access to the park through the residential neighborhoods to the east.

4. Participants asked that there be lifeguards if a sunning beach is provided.

5. Participants were enthusiastically in favor of non-motorized boating access to the lakes.

6. Many participants were in favor of fishing access and habitat improvements.

7. Participants were strongly opposed to the idea of paintball, until they understood that it would be limited to only a few acres in one controlled area – as opposed to being allowed throughout the

30 park. Paintball in a single controlled area will be OK with this group.

8. A similar discussion ensued about Dog Off Leash Area – DOLA will be OK with this group if it is confined to one, fenced, controlled area.

9. More discussion about trails – this group feels the residential areas to the east need to be well connected to the park, as opposed to isolated from it.

10. Neighbors to the east feel strongly about removing the existing chain link fence and replacing it with more attractive fencing and/or safe public access improvements to the edge of the lakes.

11. In response to questions about scheduling improvements, Mr. Wardle explained that first priority will be to complete revegetation of disturbed areas. Dawn explained that water storage should begin later this year. Gary indicated that access and trails would begin within a year or two and other master planned improvements phased in over a longer period of time.

12. Participants were concerned about the sound of pumps, which are currently noisy. Dawn explained that pumps currently in operation are temporary installations, and that future permanent pumps are planned to be on the west side of the lakes and should be installed within enclosures.

13. A few participants were strongly opposed to the idea of archery, until they understood that, like paintball and DOLA, it would be limited to one controlled area – as opposed to being allowed throughout the park. Archery in a single controlled area will be OK with most people in this group, but not all of them.

14. Participants questioned whether this facility might be large enough to have some kind of full-time supervision, like a full time caretaker, or ranger. Staff responded to the affirmative.

15. Participants asked about rest rooms and drinking water, and were told by staff that both would be provided, probably at or near parking and/or visitor orientation points.

16. Frisbee golf will be OK with this group.

17. One participant inquired about the possibility for additional ball fields at this park. Staff responded that ball fields seemed more appropriate on urban recreational parks than on this - an open space park.

Ken Mitchell Open Space Public Meeting No. 2 April 12, 2006, 6:30 PM Meeting Summary

City staff and officials attending: Gary Wardle, Mark Heidt, Dawn Hessheimer, consultant Ed Shalkey, City Councilman Daryl Meyers.

The meeting was opened by Gary Wardle, who made introductions and briefly explained the master planning process and where we are currently within it. Ed Shalkey showed and summarized the A, B, and C

31 Master Plan alternatives. The following public comments about the alternatives were recorded:

1. The mine operator’s plans for Erger’s Pit, and the impact of that mine on the neighborhood was questioned. Staff explained that the City has no control over the Erger’s Pit and it’s operations until the time that the City may have a lease or purchase agreement with that operator.

2. One neighbor requested that the sites’ nature activities be highly accessible to the handicapped or the aged, to the extent that Barr Lake, for example, has a “Train” that motors people around the site, and perhaps golf carts would work to the same benefit.

3. Some concern was expressed about the nesting area for the Herons west of Cell 2.

4. Neighbors expressed a desire for improvements to the existing Ken Mitchell Park facilities, including better rest rooms, trash collection, and a overall improvement in the day use facilities in general.

5. There were strong objections to the archery and the paintball facilities as shown especially in the locations shown. Archery did not seem to be popular in any location on the site, but paintball seemed to be OK if located in the southeast part of the site.

6. Two Dog Off Leash Areas (DOLA) were recommended – one in the southeast part of the site, and another near Ken Mitchell Park, along the east end of the divide between Cell 1 and Erger’s Pit.

7. Some recommended that the sunning beach should also have a children’s playground.

8. One Frisbee Golfer believes the “course” should be more linear, like along a trail network, it does not need a designated area, as currently shown

9. There was pretty strong agreement against a bridge over the Platte, connecting Riverdale Road to the W side of the site, citing City’s ability to monitor and supplying too much access to other than Brighton taxpayers.

10. There was pretty strong agreement about the potential for additional land acquisition in the southeast corner, to be able to move some active recreation there (like archery and DOLA), and for better access.

11. The consensus of the group was that Alternative “A” would be preferred, but modified to add additional land acquisition in the southeast. corner for relocating skate park, archery, DOLA, other active uses in that area. Reserve the west side of the site for wildlife.

32 Figure No. 6 - Overflow Culvert Concept VI. COST ESTIMATE

Cost estimating for all proposed improvements, except the storm and augmentation water improvements, have been prepared utilizing estimated quantities and unit prices as though all of these various improvements have actually been designed - which of course, they most certainly have not! Therefore, a hefty dose of skepticism must be taken with the calculations shown on the following pages - the estimates shown are probably "in the ball park", but just as probably, they may also be considerably high, or considerably low. This is the nature of cost estimating at the Master Plan scale.

Nonetheless, one estimated number equals approximately $18,712,000 for all proposed improvements, except the water works. That number divided by the approximately 373 acres of land resource, or the 607 total of land and water acreage within the planning area yield estimated per acre development costs of approximately $50,166 per acre (land only), and $30,827 per acre (land and water) respectively.

Map No. 10. - Cost Estimating Areas, correlates the various component segments of the planning area with their respective spread sheets, which follow Map 10.

33 Map No. 10 - Cost Estimating Areas