Little Dell Lake, Salt Lake City Streams, Utah
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FINAL ENVIRONMENTAL IMPACT STATEMENT LITTLE DELL LAKE SALT LAKE*£IT*Y SXREAKStiMAH U S. ARMY ENGINEER, DISTRICT SACRAMENTO, CALIFORNIA' SEPTEMBER 1974 SUMMARY Little Dell Lake, Salt Lake City Streams, Utah ( ) Draft (X) Final Environmental Statement Responsible Office: U. S. Army Engineer District, Sacramento 650 Capitol Mall Sacramento, California 95814 Telephone No. (916) 449-2232 1. Name of Action: (X) Administrative ( ) Legislative 2. Description of Action: Little Dell Lake project will be a 275-foot- high dam across Dell Creek to Impound up to 30,000 acre-feet of water. The project will include diversion structures to divert water from Emigra tion Canyon and Parleys Creek (below Lambs Canyon) into Little Dell Lake. Highway 65 will be relocated around the lake and affected utilities will be relocated. The project will be operated for the purposes of flood control, municipal and industrial water supply, and recreation and fish and wildlife. 3. a. Environmental Impacts: Flood control will be provided for exist ing and future development in Emigration Canyon, Parleys Canyon and Salt Lake City. A supply of municipal and industrial water and a new recrea tion opportunity will be available for the people of the Salt Lake metro politan area. The large numbers of people attracted to the lake for recreation will result in heavy traffic on the existing road system. A portion of Utah State Highway No. 65 will require relocation. A 1.5 mile stretch of the historic Mormon and Pony Express trail and the site of the Little Dell Pony Express Station, which is listed in the National Register of Historic Places, will be inundated. The trail and the station will be relocated adjacent to the new lake and incorporated into the public use development. About 340 acres of land will be inundated, including 35 acres of cultivated fields, and 300 acres of undeveloped land managed for water quality protection and used by wildlife. An additional 803 acres of land will be acquired in fee for use by the public and about 74 acres by easements for construction of facilities which is undeveloped except for about 2 acres of residential land. b. Adverse Environmental Effects: Wildlife habitat, including some meadow and riparian vegetation, will be inundated by the new lake. Project construction will result in some scarring of the landscape. Little Dell Pony Express Station will be moved from its historic location and 1.5 miles of the Mormon Trail inundated. Diversion of Emigration Creek water to the new lake would diminish the limited trout fishery downstream from the diversion. The aesthetic quality of the lake will be affected during infrequent heavy drawdown periods. 4. Alternatives: Different reservoir sizes; different reservoir sites; various diversions from nearby streams; future additional diversions from Mill Creek and Big Cottonwood Creek; flood plain management; downstream channel improvements; floodway on surface streets; and "no action." 5. Comments Received: U. S. Environmental Protection Agency U. S. Department of the Interior U. S. Forest Service U. S. Department of housing and Urban Development State of Utah Sierra Club, Uinta Chapter Utah Environment Center Stanley hulaik G. Draft Statement to CLQ 11 July 1973. Final Statement to CEQ FINAL ENVIRONMENTAL STATEMENT LITTLE DELL LAKE SALT LAKE CITY STREAMS, UTAH TABLE OF CONTENTS Paragraph Subject Page 1 Project Description 1.01 Location 1 1.02 Authorization and current status 1 1.03 Local cooperation 1 1.04 Project data 1 1.05 Project purposes 3 1.06 Project operation 6 1.07 Basis for determining costand benefits 7 2 Existing Resources and Environmental Impact 2.01 Physical geography 9 2.02 Geology and mineral resources 9 2.03 Climate 10 2.04 Hydrology and ground water 10 2.05 Water quality 13 2.06 Land use 20 2.07 Aestnetics 22 2.08 Archeological and historical resources 26 2.09 Recreation 31 2.10 Other natural resources 34 3 Relationship of Proposed Action to Land Use Plans 41 4 Unavoidable Adverse Effects 42 5 Alternatives 5.01 Multiple purpose plans 43 5.02 Flood control 45 5.03 Water supply 47 5.04 Recreation 49 5.05 No action 50 6 Relationship Between Local Short-Term Uses of the Environment and the Maintenance and Enhancement of Long-Term Productivity 51 7 Irreversible and Irretrievable Commitments of Resources Should the Project be Constructed 52 Paragraph Subject Page o Coordination and Comments and Responses 8.01 Public participation 53 8.02 Governmental agencies 54 8.03 U.S. Environmental Protection Agency 55 8.04 U.S. Department of Agriculture - Forest Service 56 8.05 Department of Housing and Urban Development 62 6.06 Department of the Interior 62 8.07 State of Utah 76 8.08 Citizen groups ' 78 3.09 Sierra Club, Uinta Chapter 79 8.10 Utah Environment Center 81 8.11 Stanley B. Mulaik 85 8.12 National Wildlife Federation 90 LIST OF CHARTS Chart 1 General map Chart 2 General map and possible alternative improvement Chart 3 Little Dell Lake Chart 4 Emigration Creek flows Chart 5 Lambs Canyon flows Chart 6 Map showing the results of a seepage run in Emigration Creek, August 9-10, 1965 Chart 7 Central Utah Project LIST OF PHOTOS Photo 1 Little Dell Lake Project - Looking southwest Photo 2 Emigration Creek - Upstream from Highway 65 Photo 3 Little Dell Station APPENDIXES Appendix A Economic Data Appendix B Flora and Fauna of the Little Dell Project Area Appendix C References Cited Appendix D Letters Received by the District Engineer Appendix E Memorandum of Agreement Concerning Little Dell Station and Related Correspondence FINAL ENVIRONMENTAL STATEMENT LITTLE DELL LAKE SALT LAKE CITY STREAMS, UTAH SECTION I - PROJECT DESCRIPTION 1.01 Location. - The project consists of a dam and reservoir to be constructed on Dell Creek, a tributary of Parleys Creek, about 6.5 miles east of Salt Lake City, Utah, in the western part of the Wasatch Mountains. The damsite will be 1.5 miles upstream from the existing Mountain Dell Dam. The project will Include a diversion structure and tunnel to divert water from nearby Emigration Canyon and a diversion structure Just below the confluence of Parleys and Lambs Canyons to divert the combined runoff of these creeks during high flows. Flows from both diversions will enter Little Dell Lake. Location of the project Is shown on charts 1 and 2 and photo 1. 1.02 Authorization and current status. - The Little Dell Project is in the advance planning (preconstruction) stage. The project was authorized by Congress in the Flood Control Acts of 1960 and 1968. The most recent authorization was on the basis of recommendations of the Chief of Engineers contained in Senate Document No. 53, 90th Congress, 1st Session. 1.03 Local cooperation. - The Metropolitan Water District of Salt Lake City furnished assurances for repayment of costs allocated to municipal water supply. Salt Lake County has indicated they will furnish assurances for providing the non-Federal flood control requirements, which include a contribution in cash or in kind for lands, easements, rights-of-way and relocations allocated to the flood control function. The County has also forwarded a letter of intent to assume the cost-sharing and administration responsibilities for recreation at Little Dell Lake. 1.04 Project data. - The project is shown on chart 3 and will consist of the following: a. A 275-foot high rolled earthfill dam with a crest length of 2,300 feet and a crest width of 20 feet. b. A 9-foot high diversion structure on Emigration Creek below the confluence of Burr Fork and Killyon Canyon approximately 2,000 feet upstream from where Highway 65 crosses the stream (chart 3), and a 6.5-foot diameter tunnel, 1.03 miles long, to convey water to Little Dell Lake. C. A diversion structure 8.5 feet high on Parleys Creek Just below its confluence with Lambs Canyon and a 4—foot diameter pipeline, 3.1 miles long, to convey water to Little Dell Lake. d. Recreation development: (1) 75 family picnic sites, grouped in three areas. (2) 7 group picnic areas, each accommodating up to 200 people (and possibly for use as youth camp areas). (3) One two-lane launching ramp, for non-power boats. (4) A 1-1/2 acre sand swimming beach. (5) A three-mile long asphalt bike-hike trail. e. Little Dell Pony Express Station (photo 3) will be relocated. f. The following facilities will be relocated: (1) State Highway 65. (2) Two crude oil lines. (3) Two natural gas lines. (4) One overhead telephone line. g. Reservoir data for Little Dell Lake are shown below: Gross Pool Inactive Pool Capacity 30,000 acre-feet Capacity 3,000 acre-feet Surface area 340 acres Surface area 87 acres Shoreline 4.2 miles Elevation 5,706 feet Elevation 5,835 feet h. About 7,900,000 cubic yards of borrow material will be taken from the following borrow areas for construction of the project. Areas are shown on chart 3. (1) In the reservoir area below gross pool. (2) From the spillway excavation. (3) Material excavated from Emigration Creek tunnel. (4) Material excavated from Lambs Canyon conveyance facilities. (5) If necessary, reserve borrow areas on the hillside near the left abutment and along the north shore of the lake. Concrete aggregates and heavy riprap for the lakeside face of the dam and for erosion protection at outlet structures will be obtained from commercial sources in the Salt Lake City area. Material from the above areas which is not suitable for the dam embankment will be spoiled in the reservoir area, or used to restore borrow areas to as near natural contours as possible.