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<br />0\)2j77 <br /> <br />.' <br /> <br />Based on a request from the Transition Work Group of the GCDEIS, one week of high steady <br />flows for research purposes is planned from Glen Canyon Dam in April 1996. These flows <br />would test the effectiveness of the Beach/Habitat Building flow recommendation in the <br />GCDEIS and would require bypassing the powerplant. <br /> <br />The Colorado River Management Work Group and Transition Work Group, involved with the <br />AOP and the GCDEIS respectively, support the elimination of the provision for Beach/Habitat <br />Building Flows during low reservoir storage conditions as contained in the preferred <br />alternative of the GCDEIS. These work groups also support accomplishing this action <br />through the Record of Decision process. This approach would attempt to accomplish the <br />objectives of the Beach/Habitat Building Flow recommendation of the GCDEIS utilizing <br />reservoir releases in excess of powerplant capacity required for dam safety purposes during <br />high reservoir conditions at Glen Canyon Dam. Such releases would be consistent with the <br />1956 Colorado River Storage Project Act. the 1968 Colorado River Basin Project Act and the <br />1992 Grand Canyon Protection Act. Such releases would be managed to the maximum extent <br />possible to (1) protect river sediment storage downstream or (2) be released in such a way as <br />to reshape river topography, redeposit sediment and enhance aquatic habitat. In addition. <br />installation of permanent extensions to spillway gates as provided in the preferred alternative <br />of the GCDEIS will provide infrequent. short-term control of floods for the environmental <br />protection of the Grand Canyon and for dam safety purposes. These concepts, along with <br />habitat maintenance flows up to powerplant capacity during lower reservoir conditions, would <br />be carefully monitored to ensure that the goals of environmental and endangered species <br />protection are met. Additional NEPA compliance will be completed on the permanent <br />installation of the spillway gate extensions. <br /> <br />With this proposal in place, a test of a Beach/Habitat Building flow from Glen Canyon Dam <br />could be accomplished in the spring of 1996. This test would allow scientific verification of <br />the sediment deposition mechanisms believed to be key to the long-term maintenance of <br />habitats in the Grand Canyon. NEP A and ESA compliance will be completed on this research <br />test prior to its occurrence in 1996. <br /> <br />This test in 1996 may have economic impacts due to foregone power generation and its <br />associated revenue impact to the Treasury from the water that would bypass the powerplant, <br />about 345 MCM (0.280 MAF). Such a test release, if performed for other than hydrologic <br />reasons, could result in modified monthly release volumes throughout water year 1996, and <br />may cause additional purchase power expenses during the other months of the year and low <br />value "dump energy" during the month of the test release. <br />