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Final Report 1-13 September 2000 (based on hourly values) around the flow established for a given summer period, and flows are not to be outside the 31-51 m3/s range. The date for achieving the target flow is to be based primarily on the anticipated hydrograph of the Yampa River. During normal or high water years, the target flow is expected to be achieved on or near 10 July or 20 July, respectively. During low water years, the target flow is expected to be achieved on or near June 20. Water released from Flaming Gorge Dam through the multilevel-intake structure between 1 July and 1 November should be the warmest water available (approaching 150C). By releasing the warmest water available during this period, water temperatures in the upper Green River should not differ more than 50C from the temperature in the Yampa River at Echo Park and should average near 22-250C in Gray Canyon from 1 July to 15 August. · Autumn.-Autumn flows are to be a continuation of the summer flows described above. During high water years, however, the upper limit of the target-flow range could be increased up to a maximum of 68 m3/s, because most young-of-year (YOY) endangered fishes are expected to be past the larval period of development by autumn. If water conditions change substantially, a new target flow can be selected on or after 15 September. Fluctuations in flow at the Jensen gage in autumn are to be limited to no more than 25% (based on hourly values) around the autumn target and are to be maintained within the bounds of the 31-68 m3/s range until 1 November of each year. · Winter.-Winter flows should be stabilized once ice cover has formed and should remain stable until ice breakup. An exception to this recommendation is to be allowed when evidence shows that higher winter flows are needed to achieve low summer and autumn flows. If ice formation does not occur or if specific research flows are not requested, water releases from Flaming Gorge Dam are to be based on agreements between Reclamation and the State of Utah or the need to release more water during high water years. If possible, flow fluctuations are to be moderated during winter. The 1992 Biological Opinion also called for additional research over 5 years to collect information needed to refine the flow and temperature recommendations (particularly flow recommendations for spring and winter) and to develop flow recommendations for other areas ofthe Green River (element 2 of the reasonable and prudent alternative). To address this need, the Recovery Program initiated the Flaming Gorge Flow Recommendations Investigation (Chapter 2) in 1992 to evaluate biological and physical responses of the Green River ecosystem to the seasonal flow recommendations in the Biological Opinion and to obtain information that could be used to refine the existing flow recommendations for the Green River on the basis of test-flow releases from Flaming Gorge Dam. Data collection for the Flaming Gorge Flow Recommendations Investigation concluded in 1996. During 1990 and 1991, while the Biological Opinion was being developed, research was conducted to further assess reproduction and nursery habitats of Colorado pikeminnow; those studies are considered part of the Flaming Gorge Flow Recommendations Investigation.