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" 22 EFFECTS OF THE ACTION Operation of Flaming Gorge Dam, since it began filling in November 1962, altered downstream flow, temperature, and channel morphology in the Green River due ta reregulatian .of flows and annual depletions of 78,300 acre-feet due to evaporation. Above the canfluence with the Yampa River, spring peaks were virtually eliminated and baseline flows increased during summer and winter in response to needs for water storage, spill preventian, and peak electricity. The river in this reach is sediment-poor and the channel is degrading (Lyans 1989). Spring flows of the Yampa River greatly influence the Green River hydrograph, changing an almost flat hydragraph into a more natural one. Althaugh a spring and early summer peak is maintained to some degree by runoff from the Yampa River Basin and other tributaries, the river channel is aggrading below the Duchesne River confluence (Andrews 1986). Late summer and winter flows, normally low and stable within the framework of a natural hydrograph, fluctuate cansiderably in response to highest peaking pawer demand in July, August, and September and December, January, and February, respectively. Flaming Gorge releases can fluctuate daily from 800-4,700 cfs with ramp rates as high as 500 cfs per minute based on pawer productian needs. The most dramatic effects to the hydrograph occur directly below the dam and downstream to the confluence with the Yampa River. Below the Yampa River confluence, the effects of fluctuating releases from Flaming Gorge Dam are somewhat reduced due to attenuation over the 100-mile distance as well as being ameliorated by the Yampa River flaw which remains largely uncontralled. Further downstream at Green River, Utah, the effects of fluctuating releases can still be seen but are diminished further by tributary inflaw, agricultural return flows, and attenuatian. The Consolidated Hydrology Report (Smith and Green 1991) contains additional operational information. There are other endangered species that use the Green River. Bald eagles currently use the river corridor for wintering. One pair successfully nested along the Green River in 1991. Peregrine falcons were discovered along the Green River during the 1980's. Presently there are two peregrine falcon eyries and possibly one other. Host observations were downstream of the areas significantly impacted by Flaming Gorge operation. To protect peregrine falcon eyries, exact locations will not be presented herein. The bald eagle and peregrine falcon became established along the Green River under current operation criteria and neither the present operation nor the proposed refined operatian will likely affect their presence (Steve Cranney, Utah Division of Wildlife Resources, pers.comm.). The Ute ladies'-tresses orchid, a threatened species, occurs in the Browns Park area and is not expected to be affected by the change in operation of Flaming Gorge Dam. The Service believes that the continued existing and proposed future operational criteria for Flaming Gorge Dam are likely to jeopardize the endangered Colorado sQuawfish, humpback chub, bony tail chub, and razorback sucker. Hare detail on the effects of operations on these fish and their various life history stages is contained within their respective life history sections contained in this biological opinion.