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<br />Lake Powell <br /> <br />The April through July unregulated inflow into Lake Powell in water year 1997 was 13,964 <br />MCM (11.321 MAF) or 147 percent of average, Water year 1997 unregulated inflow was <br />20,057 MCM (16261 MAF) or 139 percent of average, Lake Powell ended the water year <br />8 feet from full, <br /> <br />During March and April 1996, a test of the BeachlHabitat Building Flow was conducted from <br />Glen Canyon Dam, The test consisted of peak releases of 45,000 cfs which lasted 7 days, <br />preceded and followed by 4-day periods of low steady flows to allow photographic mapping and <br />monitoring of the canyon resources, Scientific understanding and results of this test were <br />presented in a symposium held April 8 - 10, 1997, <br /> <br />"i <br />;.,: <br /> <br />This test was implemented following discussions between the Department of the Interior, the <br />Basin States, and key scientists and researchers which resulted in a long term agreement for <br />managing spills from Glen Canyon Dam, This agreement provides for the use of reservoir <br />releases in excess of power plant capacity required for dam safety purposes during high reservoir <br />conditions to accomplish the objectives of the BeachlHabitat Building Flow described in the <br />Record of Decision for the Glen Canyon Dam Final EIS (GCDFEIS), Such releases would be <br />consistent with the 1956 Colorado River Storage Project Act, the 1968 Colorado River Basin <br />Project Act and the 1992 Grand Canyon Protection Act. Such releases would be managed to the <br />maximum extent possible to (I) protect river sediment storage downstream or (2) be released <br />in such a wa as to resha e river topography, redeposit sediment and enhance aquatic habitat. <br /> <br />Ii <br />~, <br /> <br />~; <br />.;~ <br />f/ <br />,'- <br />~; <br />,." <br /> <br />r' <br />>, <br /> <br />y:' <br /> <br />S;;. <br /> <br />s.~;, <br /> <br /> <br />;", <br /> <br />i:. <br /> <br />':"~"o' l3Q <br />"i;j . ,.t;q:,:~lt. ' ordance with the GCDFEIS and the Record of Decision, <br />e amation intends to reinstall the spillway gate extensions at Glen Canyon Dam to increase <br />the flexibility of managing high runoff years, <br /> <br />" <br /> <br />" <br />.".J <br />.;"j <br /> <br />During water year 1998, releases greater than the minimum release objective of 10,152 MCM <br />(8,230 MAF) likely will be made to avoid anticipated spills and/or to equalize the storage <br />between Lakes Powell and Mead, Under the most probable inflow conditions, releases of 13,260 <br />MCM (10,750 MAF) would be made, while under the probable maximum inflow scenario, <br />approximately 21,759 MCM (17,640 MAF) will be released, This maximum probable inflow <br />would require releases of about 708 cms (25,000 cfs) for a lengthy period of time, <br /> <br />;{; <br />~i <br />':~, <br />'.~ -i <br />,;"J, <br />;;::-, <br />",' , <br />i\~ <br />~-~ <br />~~~ <br />.;... <br />I.~ <br />~~~; <br /> <br />.~ <br /> <br />The interim flow restrictions on the daily and hourly releases from Glen Canyon Dam <br />implemented in August, 1991 were replaced during water year 1997 by the parameters of the <br />Record of Decision for the GCDFEIS preferred alternative, Operating criteria and a plan of <br />operations were issued on February 24, 1997, in accordance with the 1992 Grand Canyon <br />Protection Act. A monitoring and research program has been implemented and will continue <br />to measure the effect of operating criteria on downstream resources as part of the Adaptive <br />Management Program, Releases from Lake Powell in water year 1998 will continue to reflect <br /> <br />September 3, 1997 <br /> <br />II <br />