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<br /> <br />. <br /> <br />. <br /> <br /> <br />. <br /> <br />,. (- <br /> <br />. <br /> <br />. <br /> <br />Because the level of Lake Powell has dropped considerably since 1987, the risk of <br />releases greater than powerplant capacity during water year 1991 is negligible. <br /> <br />Monthly releases will be patterned to meet the test flows for the Glen Canyon <br />Environmental Studies (GCES) that are currently in progress. These test flows were <br />carefully selected in order to give GCES researchers specific release patterns and also <br />meet the minimum release objective of 8.23 MAF. This research at Glen Canyon will <br />greatly improve our understanding of the environmental consequences of different <br />hourly release patterns from Glen Canyon Dam. Reclamation, Western, and the Basin <br />Slates are committed to the cooperative effort required to complete the GeES studies. <br /> <br />Lake Mead <br /> <br />Lake Mead withdrawals and releases during 1991 will satisfy 7.5 MAF of beneficial <br />consumptive use requests in the Lower Basin, treaty requirements with Mexico, <br />conveyance losses, and river regulation needs. The outlook for lowest and highest <br />monthly releases for 1991 will be about 518,000 AF and 963,000 AF, respectively. <br /> <br />With the minimum objective release of 8.23 MAF from Glen Canyon Dam in 1991, <br />Lake Mead will rise to about elevation 1184 feet in February 1991 and decline to a <br />seasonal low level of about 1173 feet in the June through August period. Draw down, <br />during the peak large mouth bass spawning period in April and May, is planned to be <br />near the limits of decline recommended in the July 1982 final report of a five year <br />study by the Arizona Game and Fish Department and the Nevada Department of <br />Wildlife. <br /> <br />No flood control releases are scheduled for 1991, but in future years. as Lake Mead <br />refills and flood control releases are again required by the Hoover Dam Flood Control <br />Regulations, consideration will be given to making those releases over the fall and <br />winter months to avoid high flow rates during the January to July runoff season. This <br />distribution of water reduces the chance of bypassing hydroelectric powerplants below <br />Hoover Dam and avoids the adverse impacts of higher flood control releases on fish <br />and wildlife, recreation, water quality, and river stabilization. <br /> <br />Lakes Mohave and Havasu <br /> <br />Mohave and Havasu Reservoirs are scheduled to be drawn down in the fall and winter <br />months to provide storage space for local storm runoff and will be filled in the spring <br />to meet higher summer water needs. This draw down will also correspond with <br />maintenance at both Davis and Parker Powerplants which is scheduled for September <br />through February. The normal filling pattern of these two reservoirs coincides well <br /> <br />9 <br /> <br /> <br />- <br />