"The Secretary of the Interior, acting through the Bureau of Reclamation, proposes to take action to assist in the recovery of four endangered fish in the Green River downstream from Flaming Gorge Dam, a Colorado River Storage Project facility in northeastern Utah, with a reservoir located in Utah and Wyoming. The purpose of the proposed action is to operate Flaming Gorge Dam to protect and assist in recovery of the populations and designated critical habitat of four endangered fishes, while maintaining all authorized purposes of the Flaming Gorge Unite of the Colorado River Storage Project, particularly those related to the development of water resources in accordance with the Colorado River Compact. This draft environmental impact statement has been prepared pursuant to the National Environmental Policy Act to analyze the effects of operating Flaming Gorge Dam in accordance with a set of flow and temperature recommendations developed by the Upper Colorado River Endangered Fish Recovery Program"--Page i

"The Executive Summary provides an overview of the proposed action analyzed in the Operation of Flaming Gorge Dam Final Environmental Impact Statement (EIS). It is intended to provide a concise report of the proposed action, alternatives, and environmental consequences which are explained and analyzed in detail in the EIS"--Page 2 of cover.

This report presents the development of Flaming Gorge Reservoir release patterns and resulting downstream flows and stages for four potential hydropower operational scenarios. The release patterns were developed for three representative hydrologic years: moderate, dry, and wet. Computer models were used to estimate flows and stages in the Green River resulting from these release patterns for the moderate water year. The four hydropower operational scenarios for Flaming Gorge Dam were year-round high fluctuating flows, seasonally adjusted high fluctuating flows, seasonally adjusted moderate fluctuating flows, and seasonally adjusted steady flows. The year-round high fluctuating flow scenario assumes that the monthly total reservoir releases would be the same as historical releases. The remaining seasonally adjusted flow scenarios would comply with the 1992 Biological Opinion of the US Fish and Wildlife Service, which requires high flows in the spring and limited hourly fluctuations, especially in summer and autumn releases, to protect endangered fish. Within one year, the maximum daily river stage fluctuations resulting from hydropower operations under the seasonally adjusted high fluctuating flow scenario would be similar to the maximum daily fluctuations under the year-round high fluctuating flow scenario. However, reduced or no fluctuations would occur in some time periods under the former scenario. The maximum daily river stage fluctuations under the seasonally adjusted moderate fluctuating flow scenario would be about half of those under the seasonally adjusted high fluctuating flow scenario.