<br />Lake Powell
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<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,
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<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,
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<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.
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<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,
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<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,
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<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
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<br />September 3, 1997
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<br />II
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