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<br />. <br /> <br />. <br /> <br />- Under the Green Mountain Reservoir Operating Policy <br />of 1983, there is no longer a requirement that a flow <br />of 1250 cfs be maintained at Shoshone during the <br />irrigation season. The Division 5 Engineer now calls <br />for releases to cover specific depletions throughout <br />the river system rather than guaranteeing a full <br />supply to a senior hydropower right. The 1250-cfs <br />target flow at Shoshone was the objective in 1977. <br /> <br />- The OMID "check" will not be automatically used to <br />benefit junior rights. The "check" will be used to <br />share shortages according to existing private <br />agreements and to maximize power generation. In <br />1977, the "check" was used extensively to supply as <br />much of the GVIC 640-cfs demand as possible. <br /> <br />NATFLOW1 calculates replacement requirements for the <br />major transmountain diversion projects and water storage <br />facilities, treating reservoir evaporation as project <br />depletion. Priority status is determined by examining water <br />supplies available to the two Shoshone water rights of . <br />1250 cfs (1905) and 158 cfs (1940). The spreadsheet <br />determines the difference between historic (1977) replacement <br />requirements and those required under full administration. <br />This difference is used to adjust the historic Colorado River <br />flow at Cameo. A second adjustment is made to account for <br />historic Green Mountain Reservoir releases for irrigation and <br />municipal use on the West Slope. The desired "natural flow" <br />at Cameo should not contain any water released from storage to <br />augment irrigation supplies in the Grand Valley. An assumed <br />basin-wide depletion schedule for junior rights was used to <br />estimate the portion of Green Mountain Reservoir release that <br />was intercepted by junior rights upstream from Cameo. The <br />result is a daily hydrograph for the Colorado River at Cameo, <br />representing the amount of water which would have been <br />available to the "Cameo Call" rights in 1977 under full <br />administration of the river and without the benefit of Green <br />Mountain Reservoir releases for West Slope use. <br /> <br />The CHKPLAN series of spreadsheets take the calculated <br />"natural flow" and examine various distributions of that flow <br />among the water rights serving the Grand Valley. Different <br />assumptions about operating the "check" are used to assess the <br />benefits available through its use. CHKPLAN1 simulates the <br />operation schedule preferred by OMID, which involves no use of <br />the "check" to benefit the junior GVIC right, but does allow <br />.its use to share shortages with GVWUA and to generate <br />additional power with water destined for GVIC when available. <br /> <br />- 11 - <br />