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<br /> <br />SUMMARY <br />( ) Draft <br /> <br />(X) Final <br /> <br />Environmental Statement <br /> <br />Department of the Interior, Bureau of Reclamation, Southwest Region <br /> <br />1. <br /> <br />(X) Administrative <br /> <br />( ) Legislative <br /> <br />Type of Action <br /> <br />2. Brief Description of Action <br /> <br />The Closed Basin Division, San Luis Valley Project, Alamosa and <br />Saguache Counties, Colorado, is a multiple-purpose water resource <br />project designed to deliver to the Rio Grande water now being <br />removed by evaporative processes from the Closed Basin. With full <br />project development, water pumped from the shallow, unconfined <br />aquifer will range from 66,000 to 104,000 acre-feet per year (yield <br />objective is 100,600 acre-feet annually). This water yield objec- <br />tive less 5,300 acre-feet delivered to Alamosa National Wildlife <br />Refuge (NWR) would deliver about 130 ft3/s of water to the Rio Grande, <br />less evaporation and seepage losses. Well fields will be developed <br />in four stages (Stages 1-2, 3, 4, and 5), and each stage will be <br />designed using information gained from the previous stage. Project <br />features will consist of 95 to 165 production wells; laterals <br />(about 100 miles); electric transmission facilities; conveyance <br />channel (about 42 miles); and miscellaneous structures. The proj- <br />ect will provide for establishment of Mishak NWR; delivery of 5,300 <br />acre-feet of water annually to Alamosa NWR; stabilization of the <br />water level of San Luis Lake at about 890 surface acres; develop- <br />ment of recreational facilities at San Luis Lake; and fish and <br />wildlife enhancement. Project development is expected to extend <br />about 10 years. <br /> <br />3. Summary of Environmental Impacts and Adverse Environmental Effects <br /> <br />Pumping of the unconfined ground water will draw the water table <br />down to a minimum of 8 feet below the ground surface. Impacts on <br />wetlands and vegetation are not specifically known at this time. <br />There may be a decrease in the amount of wetlands and in the vigor <br />and density of vegetation where the depth to water table is 0 to <br />5 feet; and minimal decrease where the depth to water table is <br />5 feet Dr more. Changes in wildlife populations will be rel~ted to <br />changes in vegetation. Delivery of a minimum of about 80 ft Is of <br />water to the Rio Grande will provide higher minimum flows, increased <br />water depth, and additional water to maintain pools and riffles. <br />Concurrent with construction of Stage 1-2, incremental mitigation <br />measures will be implemented for the impacts of that stage. Impacts <br />on wetlands wi.flbe monitored and studied during construction and <br />operation of Stage 1-2, and remaining project mitigation needs will <br />be determined at that time, A supplement to this environmental <br />statement will be prepared prior to initiating construction of <br />Stage 3 if significant changes warrant. <br /> <br />4. Alternatives Considered <br /> <br />No project; salvage of surface and shallow ground water with pumping; <br />maximum fish, wildlife, and wetland considerations; and salvage of <br />surface water and shallow ground water without pumping. <br /> <br />5. Statements are bein~ Distributed to the Following <br /> <br />See attached list. <br /> <br />6. Date Statement Made Available to EPA and the Public <br /> <br />Draft Statement: <br />Final Statement: <br /> <br />April 19, 1979 <br />AlIG ? 7 1979 <br /> <br />" .\" '1" ,oiJ'" <br />t'v\: ",11. <br /> <br /> <br />. <br /> <br />III <br />