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<br />[3 Executive Summary <br />5-14 <br />~ DEIS - Navajo Reservoir Operations <br /> <br />500/6000 Alternative <br /> <br />This alternative was considered as a way to reduce potential impacts to the ability of <br />downstream water users' ability to take water at their diversion structures by providing a <br />higher minimum flow release of 500 cfs. <br /> <br />In addition, it attempts to minimize impacts to downstream recreation (trout fishery and <br />rafting) by maintaining higher minimum releases during certain critical times of the year <br />than does the 250/5000 Alternative. However, it has the same limitations as the 250/6000 <br />Alternative and also does not fully meet the Flow Recommendations. The 6,000-cfs release <br />also exceeds the channel capacity, as discussed under the 250/6000 Alternative. <br /> <br />Decommission and Breach Navajo Dam <br /> <br />This alternative largely meets the conditions of a natural hydrograph, and removal of the <br />dam would provide the endangered fish with access to the portion of the San Juan River <br />now inundated by Navajo Reservoir, as long as fish passage is provided throughout the <br />river. Although large spring peaks would be provided most years, low flows during the <br />irrigation season would still be impacted by downstream diversions that would result in <br />low flows substantially below 500 cfs downstream of Farmington. Therefore, this <br />alternative does not meet the Flow Recommendations. <br /> <br />This alternative is considered unreasonable and impractical because it does not meet all <br />the elements of the purpose and need for the proposed action and would not support <br />maintaining the authorized purposes of the Navajo Unit. It would result in loss of reservoir <br />storage needed to allow contract water deliveries to the San Juan-Chama Project, the NIlP, <br />and other contractors, and would make it extraordinarily difficult, if not impossible, for the <br />States of New Mexico and Colorado to fully utilize their consumptive use apportionments <br />under the Upper Colorado River Basin Compact. It also could precipitate expensive <br />litigation of Indian versus non-Indian water rights in both States. In addition, this <br />alternative would result in the loss of the following benefits provided by Navajo Dam and <br />Reservoir: downstream flood control, reservoir and tailwater fisheries, reservoir and <br />downstream recreation, and hydropower generation. The concept of decommissioning or <br />removing the dam is beyond the scope of the proposed action. <br /> <br />Alternatives Retained for Further Consideration <br /> <br />The following three alternatives were retained for further consideration. Their ability to <br />meet Flow Recommendations criteria is shown in figure 5-5, and flow statistics are shown in <br />tables 5-3 and 5-4. <br />