Aspinall EIS - Scoping Report May 2007

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The Unit is located 50 miles upstream from habitat of the endangered fish species; however, operation of the Unit c hanged the flow regime of the lower Gunnison River and to a lesser extent the Colorado R iver within what is now critical habitat for endangered fish . The Gunnison River provides habitat for two of the endangered fish species, the Colorado pikeminnow and th e razorback sucker. The 50 miles of river downstream from Delta, Colorado, are designated as critical habitat for these species. These and two additional endangered fish species — the humpback chub and bonytail chub — occur in the Colorado River downstream f rom the mouth of the Gunnison River. Operation of the Unit is important in determining the flow pattern of the Gunnison River, and to a lesser extent, the Colorado River. Since 1988, the Upper Colorado River Endangered Fish Recovery Program has worked to address endangered fish issues in the upper Colorado River . The Recovery Program is a partnership created to recover the endangered Colorado pikeminnow, razorback sucker, humpback chub, and bonytail while allowing for continued and future water develop ment. The Recovery Program was initiated in 1988 when a cooperative agreement was signed by the Governors of Colorado, Utah and Wyoming; the Secretary of the Interior; and the Administrator of the Western Area Power Administration. Recovery Program partn ers include the Colorado River Energy Distributors Association, Colorado Water Congress, Western Resources Advocates, State of Colorado, State of Utah, State of Wyoming, The Nature Conservancy, Reclamation, the Fish and Wildlife Service, National Park Serv ice, Utah Water Users Association, Western Area Power Administration, and Wyoming Water Association . The program has 5 elements: habitat management, which includes developing river flow recommendations; habitat development; nonnative species management; e ndangered fish propagation and stocking; and research and monitoring. The Aspinall Unit Operations EIS will assist in address ing the habitat management element. The operation of the Aspinall Unit is a key component of the Recovery Program for offsetting a dverse effects of flow depletions from the Gunnison and Colorado rivers and allowing water development in the Upper Colorado River Basin. Other elements of the Recovery Program are ongoing or planned for the Gunnison River and include the fish passage at the Redlands Diversion Dam, a fish screen on the Redlands Canal, bottomland habitat development near Whitewater and Delta, stocking, and research and monitoring. Flow Recommendations for the Gunnison River were prepared by the Fish and Wildlife Service and the Recovery Program using the results of research and monitoring activities funded as part of the Recovery Program and are presented in the July 2003 report titled “Flow Recommendations to Benefit Endangered Fishes in the Colorado and Gunnison River”. The goal of the recommendations is to provide the annual and seasonal patterns of flow in the Gunnison River and in the Colorado River downstream from their confluence to recover populations of the four endangered fishes. The degree to which Flow Reco mmendations are met for the Gunnison River will be modeled and measured at the Whitewater USGS gage (Gunnison River near Grand Junction). Only approximately 50 percent of the basin above this point is regulated by the Aspinall Unit, thus it is apparent th at Unit operations can only partially assist in meeting recommendations. 5