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<br />U'';;:''<J'O,J .. <br /> <br />Affected Environment & Consequences <br /> <br />3-22 <br /> <br />In summary, the introduction of hydropower flows from the Gunnison River would affect <br />the Uncompahgre River. The river channel would be expected to widen, rather than <br />degrade. The amount of widening would vary, but would be expected to average about <br />16, 19, or 25 feet for Alternatives E-3, E-2, and E-l, respectively. This widening would <br />occur within the floodplain and would not impact agricultural ground, which would be <br />protected by implementing bank stabilization measures. Infrastructure features, such as <br />bridges or canal diversions, would also be protected. <br /> <br />3.5 Water Temperature <br /> <br />3.5.1 Existing Conditions <br /> <br />3.5.1.1 Gunnison River <br /> <br />In the summer, water temperature affects dissolved oxygen in the river, which in turn <br />affects the fishery. As discharges increase, water temperatures are less influenced by air <br />temperatures. However, during periods of low summer flow, water temperatures <br />increase. In the winter, ice will form if temperatures become too cold and flows are low, <br />which could affect species using the river during the winter months, such as eagles, river <br />otters, and waterfowl. Water temperatures of the Gunnison River between Crystal <br />Reservoir and the confluence with the North Fork are highly influenced by Crystal <br />Reservoir releases. Water temperature is generally highest at the confluence with the <br />North Fork during August when flows are lowest (See PElS for additional discussion). <br /> <br />3.5.1.2 Uncompahgre River <br /> <br />Maximum summer temperatures of 20 oC (68 OF) on August 31, 1983 and 24 oC (75.2 <br />OF) on July 10, 1986 were recorded at the Colona and Delta gauging stations, <br />respectively. Low winter flows in the Uncompahgre River make winter icing common. <br /> <br />3.5.2 Impacts of Alternatives - Gunnison River <br /> <br />3.5.2.1 Alternative A (No Action) <br /> <br />It is likely that reregulation of Aspinall associated with endangered fish species <br />consultation will lead to a more natural hydro graph than has been the practice since the <br />1950s. Conditions that have occurred from 1991 through the present (the flow testing <br />period) are likely to become more prevalent. Lower releases during the winter may lead <br />to somewhat lower winter temperatures. Icing would be more frequent, but still relatively <br />uncommon. Temperatures during the balance of the year should be relatively unchanged. <br /> <br />.. <br /> <br />AS Lateral Hydropower Project <br /> <br />July 2000 <br /> <br />. .-J. <br /> <br />1" <br />:J, <br /> <br />.",. <br /> <br />. -.&-1\ --h';.\C.-.uL,-~:: _~~,.' <br />