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both of the alternatives analyzed in the DEIS, the model predicts the water surface <br />elevation of Flaming Gorge Reservoir as well as the flows in the Green River at various <br />points downstream from the dam. <br />Under the No Action Alternative, the bypass tubes would be used in 23% of all years, and <br />the spillway would be used in 5% all of years. In comparison, for the Action Alternative, <br />the Flaming Gorge Model predicts more frequent use of the bypass tubes and spillway at <br />Flaming Gorge Dam. Under the Action Alternative, the Flaming Gorge Model predicts <br />that the bypass tubes would be used in 50% of all years, and the spillway would be used <br />in 29% of all years. <br />A review of the Flaming Gorge Model was performed by three authors of the 2000 Flow <br />and Temperature Recommendations to evaluate whether the degree of bypass and spill <br />predicted by the Flaming Gorge Model would be necessary. The main focus of the model <br />review was the frequency of bypass and spillway use. The reviewers also examined the <br />model's behavior and evaluated how the model simulated the year-round operation of <br />Flaming Gorge Dam. <br />In most situations, the reviewers found that the Flaming Gorge Model properly simulates <br />the operation of Flaming Gorge Dam. The reviewers found that the Flaming Gorge <br />Model performs well in dry, moderately dry, and average years; however, the review <br />showed that the model appeared to bypass or spill more water than may be necessary in <br />some moderately wet and wet years. <br />The lack of flexibility within the operational rules of the model was the main reason <br />bypasses and spills were higher than necessary in the Flaming Gorge model. While many <br />model rules allow for decision trees, a model such as the Flaming Gorge Model cannot <br />adjust to all situations or consider the balance of all available operating options. <br />Reclamation acknowledges that the Flaming Gorge Model may overstate bypasses and <br />therefore may overstate potential effects that result from the bypassing of water. <br />Reclamation also notes that while the Flaming Gorge Model provides good information <br />to assess potential effects, details and flexibility that cannot be captured by modeling will <br />be factored into operational decisionmaking each year. <br />S.13 OPERATIONAL DESCRIPTION <br />The following discussion provides further clarification on operations under the No <br />Action Alternative and the Action Alternative, while maintaining the authorized purposes <br />and ensuring safe operations of Flaming Gorge Dam under normal operational <br />conditions. As noted in section S.6, operational plans could change due to malfunction of <br />the dam and powerplant equipment and during public emergencies. <br />SAM Safe Operation of Flaming Gorge Dam <br />Safe operation of Flaming Gorge Dam is of paramount importance and applies to both the <br />No Action Alternative and Action Alternatives. To safely and efficiently operate <br />Executive Summary A S-19