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16 <br />'impoundment temperatures-ranged from 33°F. to 70°F. at Greendale (0.5 <br />• <br />MBD; Figure 2) while post-impoundment monthly means ranged from 35°F. <br />to 54°F. Effects of the dam upon river temperature were Less pro- <br />nounced-downstream. -Near Jensen`(93.4 MBD) seasonal changes in water <br />temperatures were affected little by the dam in 1963, but summer temper- <br />atures in 1964 and 1965 were 5° to 6°F. lower than the pre-impoundment <br />average. <br />The summers of 1964 and 1965 were cooler than the summer of 1963 <br />(annual mean air temperatures were 44.9, 43.9, and 48.4 respectively) <br />which may explain the observed-departure from the average. During <br />1963, however, discharge through the turbines at Flaming Gorge was mini- <br />mized to allow the reservoir to fill (Table 3). In 1964 and 1965, much <br />larger releases of water were made which probably influenced tempera- <br />tures farther downstream than did the small releases of 1963. Summer <br />water temperatures at Allen Ranch (26.5 MBD) were lowest in 1964 (the <br />year of maximum summer discharge) and highest in 1963 (the year of <br />minimum summer discharge) even though water released in 1963 was colder <br />than that in 1964 and 1965 (Figure 3). Lower water temperatures ac- <br />companied high discharges downstream from Flaming Gorge at Carr Ranch <br />(42.7 MBD) and Echo Park (64.4 MBD). Below the confluence of the Green <br />and Yampa Rivers little relationship between temperature and flow was <br />observed since the mean annual discharge of the Yampa exceeded that of <br />the Green during 1963-1965 (1753 cfs and 1341 cfs respectively). <br />Turbidity <br />Water drawn from the reservoir was nearly sediment-free during <br />1963-65, but three major tributaries below the dam discharged turbid <br />