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<br />I <br /> <br />29 <br /> <br />depend an the water year with longer release periods in wet years and <br />sharter release periods in dry years. A determination of whether it is a <br />wet, average, or dry year will be made by the Service and Reclamation <br />during the April coordination meeting. <br /> <br />We recagnize conditions will vary each year depending on water <br />conditions. However, as a guideline, to achieve a gradual increase in <br />peak flows at Jensen, Utah, between April 1 and Hay 15 of each year, <br />releases from Flaming Gorge should be gradual (i.e., no more than 400 cfs <br />per day) and should reach at least 2,000 cfs during May. Then a peak <br />flow release of 4,000-4,700 cfs would be made beginning between May 15 <br />and June 1 for 1 to 6 weeks. Likewise, the postpeak decline should <br />gradually be stepped down (i.e., a rate of nat more than 400 cfs per day) <br />and be synchronized with the drop in spring runoff in the Yampa River. <br />If Reclamation and Western Power so chose, releases may fluctuate during <br />the ascending and descending arms of the spring hydrograph. However, <br />flows must attenuate by Jenson, Utah, and follow the hydrograph described <br />above. When natural flaw (>9,000 cfs) from the Yampa River is <br />unavailable for an extended spring peak, then a brief peak with releases <br />remaining at 4,000-4,700 cfs for only I week is acceptable from Flaming <br />Garge Dam as long as it coincides with the highest flows from the Yampa <br />River. During normal water years, the entire spring peak will .occur for <br />a period of about 6-8 weeks. If it becomes necessary to bypass water <br />from Flaming Gorge Dam to alleviate problems with storage, then the <br />bypass should occur during .or prior to the spring peak of the Yampa <br />River, as has occurred occasionally in the past. <br /> <br />The peak spring flow as described above should stimulate spawning <br />migratian, prepare substrate for spawning, and prepare nursery areas for <br />larval fish later in the year. Bottomlands in the Jensen and Ouray areas <br />also would flood, thereby providing habitat and food for native fish. <br /> <br />Summer <br /> <br />Green River flows should continue decreasing, attaining a target flow of <br />between 1,100-1,800 cfs at Jensen, Utah. Although historic summer and <br />fall flows generally fell within this range, varying hydrologic <br />conditions sometimes produced SUmmer flows higher than these. It is the <br />intent of the summer recommendation to optimize available nursery habitat <br />shown to be necessary for larval Colorado squawfish. The date for <br />achieving the target flow will be established based on the Yampa River <br />hydrograph and using the following guidelines. During dry years, when <br />the spring peak is abbreviated, larval squawfish should reach the nursery <br />areas around June 20. During normal and wet years, the target flow <br />should be achieved on or near July 10 and July 20, respectively. The <br />dates presented herein are based on past spawning and larval drift data <br />and are typical for dry, wet, and normal water years. The actual dates <br />will be determined based primarily on the timing of runoff in the Yampa <br />River. Also, if during the course of spring and/or summer annual <br />monitoring more precise data becomes available, Reclamation and the <br />Service will adjust the target date, ensuring that nursery habitats are <br />maximized when larval endangered fish drift into the Green River. Based <br />