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<br />..." - ~ <br />',. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />~ <br /> <br />.-, <br />\ i <br /> <br />35 <br /> <br />fine sediments from the cobbles. The Service is actively pursuing the <br />collection of additional data to improve the flushing flow analysis. Sediment <br />transport data will also be gathered in future years as part of the Colorado <br />river studies. <br /> <br />Given the limitations of the available hydraulic and sediment data, the effect <br />of the Ruedi II/Green Mountain water sales was only evaluated against the <br />10,000 cfs flushing flows. Evaluation of the 31-year period of record has <br />shown that the 10,000 cfs flow was exceeded during 23 years. For the 8 years <br />that the flushing flow is not met, the water sales further reduce the flows <br />during 3 years. The recurrence interval (1.1 years) of peak flows greater <br />than 10,000 cfs will not change appreciably as a result of the Ruedi II/Green <br />Mountain water sales. Reductions in the magnitude of the peak flows are less <br />than 1 percent of the total flow, therefore, the projects are not expected to <br />appreciably affect the capability of the peak flows to flush fine sediment <br />from the cobble substrate. <br /> <br />CONSERVATION MEASURES <br /> <br />Water depletions have been recognized by the Service as a major source of <br />impact to endangered fish in the Upper Colorado River Basin. The Service <br />believes that the additive effects of water depletions on the habitat <br />conditions for Colorado squawfish are very evident in the IS-mile reach, <br />especially during summer months. Our analysis of the hydrologic data provided <br />by Reclamation demonstrates that the Ruedi/Green Mountain water sales will <br />cause additional depletions and loss of Colorado squawfish habitat in the <br />IS-mile reach during most months of the year. Most of these impacts will <br />occur during the fall, winter, and spring of the year, and some will occur <br />during the summer. The significance of these impacts, especially during the <br />nonspawning months (October-June) cannot be specifically described at this <br />time. However, the Service believes that the implementation of the following <br />conservation measures will insure that the effects of the proposed water sales <br />are not likely to jeopardize the continued existence of the Colorado <br />squawfish. Because flows will result in an improvement of habitat conditions <br />during the critical life stage of the Colorado squawfish (spawning and <br />recruitment), these conservation measures will also increase the likelihood <br />for the survival and recovery of this species. <br /> <br />(1) Dedicated Storage of Ruedi Reservoir Water and Modified Operation of <br />Ruedi Reservoir. <br /> <br />Water in the amount of 5,000 af will be withheld from sale at Ruedi Reservoir <br />and will be made available as instream flows to preserve habitat conditions in <br />the IS-mile reach. The Service, in consultation with Reclamation, will <br />determine when the withheld water will be needed for endangered fish flows. <br />The water withheld from sale will be treated as if it were subject to contract <br />