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• Finding of No Significant Impact at Flaming Gorge Powerplant Uprating, Dtah-Wyoming, Colorado River Storage Project The proposed action would not constitute a major Federal action having signifi- ' cant environmental impacts. t ' The following is a summary of the expected impacts: 1. At normal reservoir elevations, maximum flows from the powerplant in the Green River below Flaming Gorge Dam would increase from 4,125 cis to 4,950 cis. Utilization of the increased capacity from uprating the generators would cause higher flows than those presently occuring approximately 7 percent of the time. These flows would be of short duration (usually less than 4 hours) and would be dampened as they move down the river. During periods of increased flows, wetted perimeter along the river between the dam and the Greendale gage would increase by an average of 3 feet horizon- tally, which is less than a 2 percent increase. This would not cause any significant erosion of streamside vegetation. The present pattern and duration of flows below 1,250 cis would not be changed from present operations and the present sources of groundwater that support riparian vegetation would not be altered; therefore, impacts on existing ripar- ian plant and animal communities would not be measurable. 2. The increase in flows would occur at the high end of the flow pattern and would not affect the minimum flows. The water from the reservoir would come from the same penstocks as at present; therefore, there would be no change in the temperature or the chemistry of the water. Habitat simulation models showed essentially no change in useable area for fish. Based upon this informa- tion, no measurable impact is expected on the quality of fishery resources below the dam. 3. Using data cited in Paragraphs 1 and by the U.S. Fish and Wildlife Service and there would be no impact on threatened or uprating. This was confirmed by the U.S. concurred with Reclamation's determinatio• dated August 11, 1986. 2 above, plus other studies conducted Reclamation, it was concluded that endangered species because of the Fish and Wildlife Service which n of "no effect" in a memorandum 4. Operational patterns would continue essentially as historically; therefore, no additional impacts on recreation are expected. 5. There would be no impact on known historical or archaeological resources as surveys indicate they are located above the area that would be affected by increased flows.