9631 - Laserfiche WebLink

Home Browse Search

there would be some years classified as moderately wet when the conditions of these factors in table S-4 would be such that targets established for the wet or average classification would be met. There could also be years classified as wet where moderately wet targets would be achieved because of the conditions of these factors. It would be the responsibility of Reclamation to ensure that, over the long term, Flaming Gorge Dam and Powerplant are operated consistent with the 2000 Flow and Temperature Recommendations. The operations plan would describe the current hydrologic classification of the Green River Basin and the hydrologic conditions in the Yampa River Basin, including the most probable runoff patterns for the two basins. The operations plan would also identify the likely Reach 2 flow magnitudes and durations that would be targeted for the upcoming spring release. Because hydrologic conditions often change during the April through July runoff period, the operations plan would contain a range of operating strategies that could be implemented. Flow and duration targets for these alternate operating strategies would be limited to those described for one classification lower or two classifications higher than the classification for the current year. The spring operations plan would be presented to the Flaming Gorge Working Group each spring for discussion. Reclamation could modify the plan based on information gathered at the Flaming Gorge Working Group meeting. In years classified as wet, bypass releases would usually be required both to operate the dam safely and to meet the 2000 Flow and Temperature Recommendations. Releases above powerplant capacity would be expected to be made for a period of about 4 to 9 weeks. The exact magnitude of the release and duration of the release would depend upon factors identified in table S-4. Wet years, high releases would be expected to occur from mid-May to early July (and, in very wet years, through July). The bypass and spillway releases, required in wet years, would be timed with the objective of meeting Reach 2 wet or moderately wet year targets, depending upon the hydrologic conditions in the Yampa River. The initiation of bypass and spillway releases would take place in mid- to late May coincident with the Yampa River peak. In extremely wet years, releases above powerplant capacity could be initiated in April or early May before the Yampa River peak. In years classified as moderately wet, bypass releases usually (but not always) would be required for safe operation of the dam and to meet the 2000 Flow and Temperature Recommendations. Occasionally, some use of the spillway also might be required in moderately wet years for safe operation of the dam. The volume of the powerplant bypass in moderately wet years would be less than in wet years and would generally occur for a period of about 1 to 7 weeks. The timing of these releases would be from mid- to late May into June and sometimes extend into July. Releases from Flaming Gorge Reservoir in moderately wet years would be timed with the objective of meeting Reach 2 wet, moderately wet, or average year targets, depending upon the hydrologic conditions in the Yampa River basin and the information contained in table S-4. In years classified as average, bypass releases likely would not be required for safe operation of the dam but periodically would be required to meet the objectives of the 2000 Flow and Temperature Recommendations. In most average years, spring peak releases would be limited to powerplant capacity (about 4,600 cfs) with peak releases taking place for about 1 to 8 weeks, usually in the mid-May to late June (but occasionally extending into July) time period. In about 1 out of every 3 average years, bypass releases Executive Summary 0 5-25