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<br />I <br /> <br />23 <br /> <br />ENVIRONMENTAL BASELINE <br /> <br />The environmental baseline includes the past and present impacts of all <br />Federal, State, .or private actions and other human activities in the actian <br />area; the anticipated impacts of all praposed Federal prajects in the action <br />area that have already undergone formal or early Section 7 consultation; and <br />the impact of State or private actions which are contemporaneous with the <br />cansultation in pracess. <br /> <br />Past Federal, State, and private actions which resulted in depletians in the <br />Green River are presented in Table 1 and Appendix A. To place this <br />informatian in perspective, the tatal patential (water already allocated <br />although not all may be used in any given year) depletions accumulate to <br />appraximately 1,572,552 acre-feet annually, at .or abave Green River, Utah. <br />Comparing this to the Green River flow at Green River, Utah, which averaged <br />around 4,648,000 acre-feet over the past century, the depletions (real and <br />potential) represent appraximately 32 percent of the flow of the Green River. <br />The total depletion far the entire Green River system is approximately <br />1,583,960 acre-feet. <br /> <br />The 32-percent depletion of the Green River affects endangered fish in two <br />ways. First, any depletion above Flaming Gorge Dam decreases the amount of <br />water which can be regulated for endangered fish (i.e., historic spring peaks <br />may not be attainable). Secondly, any depletion belaw Flaming Gorge Dam is a <br />net loss .of water available far endangered fish. Other impacts of Flaming <br />Garge Dam and current operatian include changes in the temperature regime; <br />the magnitude, timing, and duration of the spring peak; and the amount of <br />daily fluctuation .occurring in the Green River. Late spring and summer <br />temperatures in the Green River were moderated as a result of releases from <br />the reservoir. Summer-winter flaws were generally higher than thase observed <br />historical'ly. With the exception of very wet years, the magnitude of the <br />spring peak seldom approaches historic levels. <br /> <br />Table 1. Summary of water depletions in the Green River Basin. <br /> <br />RIVER/AREA DEPLETION (Acre-feet) <br /> <br />Green River above Flaming Gorge <br />Upper Green River in-Utah <br />Yampa River <br />little Snake River <br />Duchesne River <br />White River <br />Lower Green River <br />San Rafael River <br /> <br />372,331 <br />145,089 <br />129,841 <br />48,800 <br />542,118 <br />131,456 <br />125,325 <br />89,000 <br /> <br />1,583,960 <br /> <br />TOTAL <br />