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002210 During this time period, if the flow at the Shoshone Diversion Dam (WDID 530584), as measured at the Dotsero stream gage (Gage 09070500), was less than 1,250 cfs, the division engineer would fIrst curtail all transmountain diversions (other than CBT) before making a release from Green Mountain Reservoir. As a result of this method of administration, Green Mountain typically remained reasonably full during the summer irrigation season and was drawn down beginning in September and reaching its low point in storage by the end of April of the following year. A signifIcant portion of the water was being released for power generation without the additional benefit of supplementing existing Western Slope irrigation uses. In 1985, the division engineer began to administer the river in accordance with the priority system, with the result that many of the transmountain diversions that historically had been curtailed by the division engineer (Denver and Colorado Springs) were actually in priority and entitled to divert. The junior rights that would be called out by the Shoshone Call and/or the Cameo Call were more likely to be junior Western Slope water users. This method of administration has tended to trigger an earlier release of water from the 100,000 acre-foot power pool in Green Mountain Reservoir. Future Operations of Historic User Pool. In addition to Shoshone, the primary call on the Colorado River is associated with a number of senior water rights that divert for irrigation and power purposes in the Grand Valley area near Grand Junction. Collectively, the demands for these rights are referred to as the Cameo Call (See separate documentation regarding these rights). As described in the accompanying documentation, the magnitude of the Cameo call is dependent upon operation of the Orchard Mesa Check, a facility that can be operated in a manner that could reduce the call. Issues related to the operation of the Check structure are currently the subject of litigation in Case No. 91CW247, the Orchard Mesa Check Case. Resolution of these issues will have a significant impact on the future operations of Green Mountain Reservoir, in particular, the historic user pool. As part of settlement discussions in the referenced case, the USBR, in conjunction with the division engineer, is to develop criteria for the operation of the historic user pool with the objectives of: (1) Ensuring that suffIcient water is available in Green Mountain Reservoir to meet the replacement needs of the historic user pool beneficiaries; (2) Ensuring that suffIcient quantities of water are available in the historic user pool to meet direct delivery needs at Cameo; (3) Ensuring that suffIcient water remains in the historic user pool at the end of each irrigation season to meet winter demands of historic user pool benefIciaries; and (4) Providing a methodology to determine the amount of the historic user pool that is surplus to the anticipated needs of the historic user pool benefIciaries and would therefore be available for delivery for other beneficial uses in the Colorado River basin, including augmentation of flows in the critical 15-Mile Reach for protection and recovery of endangered fIsh species. As of March 1996, the studies performed by the USBR have indicated that amount of water that needs to be reserved for historic user pool benefIciaries upstream of the Shoshone power plant may be only about 15,000 acre-feet annually (out of the 66,000 acre-feet in the historic user pool). The reduction is largely a reflection of replacing only the consumptive use as opposed to headgate diversion requirements. The USBR and division engineer have developed a preliminary rule curve for the release of water from the historic user pool, consistent with the above objectives. Consolidated Case Nos. 2782, 5016 and 5017 (the Blue River Decree). In this 1955 adjudication, the relative priorities of the storage rights and hydro rights for Green Mountain Reservoir and the upstream rights at Dillon Reservoir and the Continental-Hoosier System (Colorado Springs) were specifIed. tal Hoosier System 77 cfs ountain Reservoir fs 6,315 acre-feet 788 cfs illon Reservoir 252,678 acre-feet ntinental-Hoosier System 400 cfs Continental-Hoosier Storage 5,306 acre-feet In this decree, Colorado Springs and Denver obtained the right to divert and store water at their upstream facilities on an out-of-priority basis, if it can be determined that Green Mountain Reservoir will likely fIll. Because the cities have storage in the upper Blue River basin, they are in a position to repay Green Mountain in the event the latter did not achieve fill. This agreement to allow out-of-priority upstream diversions is assessed only against the senior storage decree at Green Mountain and does not apply to an administrative call placed by the Green Mountain direct flow hydro right because the cities agreed to pay power interference charges to offset the potential impacts of upstream diversions as against the hydro right.