9631 - Laserfiche WebLink

Home Browse Search

In 1978, the dam was retrofitted with a selective withdrawal structure to improve water temperatures for the tailwater trout fishery. During the third phase, from 1979 to 1984, operations were similar to those in the previous phase except for use of the selective withdrawal structure and the occurrence of spills in 1983 and 1984. During the fourth phase, from 1985 to 1992, Reclamation began to constrain the operation of Flaming Gorge Dam to reduce negative impacts affecting endangered fishes in the Green River. Such constraints reduced operational flexibility and the ability to fluctuate flows to meet power system demands. In 1985, an interim flow agreement was established between Reclamation and the U.S. Fish and Wildlife Service to change Flaming Gorge Dam releases to protect critical nursery habitats for endangered fishes in the Green River downstream from Jensen, Utah. The recommended releases were based on observations made in 1985 that indicated "good" habitat conditions were available at lower flows. Reclamation also revised operational criteria at the dam to avoid spills. These changes were in place in the fourth phase, along with numerous research releases to support preparation of the Final Biological Opinion on the Operation of Flaming Gorge Dam issued on November 25, 1992. Significant financial impacts to hydropower generation, identified in the DEIS, occurred mainly as a result of flow changes implemented during this fourth phase. In the fifth phase, from 1993 to present, Reclamation began making releases from Flaming Gorge Dam in an attempt to meet the flow and temperature recommendations given in the 1992 Biological Opinion. Flows recommended in the 1992 Biological Opinion were intended to restore a more natural hydrograph and protect nursery habitats of endangered fishes downstream from the Yampa River confluence. At the same time, Reclamation continued to meet the authorized purposes of Flaming Gorge Dam- regulating flows of the Green River, storing water, facilitating States' development of water resources, providing recreational opportunities, generating hydroelectric power, and improving conditions for fish and wildlife. The Green River flows recommended in the 1992 Biological Opinion were based on the most reliable scientific data available at the time. The opinion included several actions Reclamation could take to avoid jeopardizing the recovery of endangered fishes in the Green River. One of these actions was to collect more information about the flow and temperature needs of the endangered fishes and, subsequently, to refine or modify the flow and temperature recommendations of the 1992 Biological Opinion. A 5-year research study began in 1992, and the resulting data and refinements were included in the 2000 Flow and Temperature Recommendations. The study included periodic test flows to evaluate the effects of summer flows on endangered fishes or to test specific hypotheses. S.5 COMPLIANCE WITH THE ENDANGERED SPECIES ACT To comply with the ESA, an evaluation of the effects of any discretionary Federal action must be conducted by the action agency in consultation with the U.S. Fish and Wildlife Service. During the late 1970s and early 1980s, the U.S. Fish and Wildlife Service rendered Jeopardy Biological Opinions for the Upalco, Jensen, and Uinta Units of the Central Utah Project stating that all relied on the operation of Flaming Gorge Dam to provide flows for endangered fishes. More recent Biological Opinions for the Duchesne River Basin, Executive Summary ? S-5