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<br />during both the 1989 and 1990 water years when, under the new administration, the 66,000 AF <br />pool was essentially exhausted at the end of the irrigation season. Although 1989 and 1990 were <br />dry years, they were not as severe of a drought as occurred in 1977. <br /> <br />In order to identify the potential impact of the new administration on west slope users and Green <br />Mountain storage, an analysis of historic and current administration of the Check was made for the <br />1977, 1989 and 1990 water years. The study used daily flow and reservoir release schedules <br />maintained by the Bureau to calculate the natural flow of the Colorado River at the Roller Dam <br />without releases of water from Green Mountain Reservoir. Green Mountain releases were modeled <br />for all three years, first to satisfy the Cameo demand under historic administration and second to <br />satisfy the demand under present administration. <br /> <br />7977 ANALYSIS <br /> <br />, <br /> <br />Figures 5 and 6 graphically display the impact of the change in stream administration on Green <br />Mountain releases and west slope beneficiaries in the drought year of 1 977. Had the Check been <br />administered as it is currently, an additional 56.600 AF of water would have been released from <br />Green Mountain Reservoir in order to adequately protect west slope beneficiaries (Figure 5). <br />Therefore, had the new administrative policy been in effect at that time, the amount of storage <br />dedicated to the west slope beneficiaries under the Bureau's operating policy would have been the <br />entire 100,000 AF power pool, not 66,000 AF. <br /> <br />. <br />,I; <br />II <br /> <br />,. <br />-:>: <br /> <br />, <br />~ <br /> <br />T <br /> <br />r. <br />. <br />. <br /> <br />In future drought years, the current administration of the Check will cause the 66,000 AF <br />beneficiary pool to be exhausted prior to the end of the irrigation season. .Figure 6 displays that <br />under the new system, reservoir releases in a drought year will have to begin one month earlier <br />(June 18th vs. July 14th). The 66,000 AF pool is exhausted by.September9th, six weeks before <br />the end of the irrigation demand in the Grand Valley region. Thus, during late September and early <br />October there would be potentially no water available for release to protect west slope <br />beneficiaries. During this period, hundreds of water users could be placed on call at a time they <br />otherwise would have been protected by the reservoir under historic administration practices. <br /> <br />1 <br />! <br /> <br />13 <br />