WSP02110 - Laserfiche WebLink

Home Browse Search

J '1"14 ..,..,., '. _, _.. < '.' J j <j ~ , SUMMARY .,~ ~ ,.\ , .. -t WATER QUALITY AND TEMPERATURE , " Under the no-action alternative, water quality in the Gunnison River would not change significantly, Water quality in the Uncompahgre River has historically been poor but may improve as Ridgway Reservoir will settle out sediment and other pollutants. , '2 . :1 ::i . Under the development alternatives, additional diversion from the Gunnison River would reduce the volume of high quality water available to dilute lesser quality tributary inflows. This reduction in water quality would occur primarily downstream from the North Fork. Temperatures in the Gunnison River would be slightly colder in the winter and warmer in the summer. The con- ditions under which ice forms in the Gunnison River would OCcur more frequently under the development alternatives, Ice accumu~ lation would be most extensive below the North Fork confluence but would also increase above this tributary, Alternative F provides operational changes to decrease diversions and, therefore, increase flows if ice conditions would create environmental problems, The Gunnison River's capacity to remove sediments would be reduced, particularly in the winter, Alternative E would provide for bypassing flushing flows when needed, ' ! . ~ ;~ I " .'1 Water supplies in the Uncompahgre River in the 12-mile reach between the South Canal and Montrose would receive less high quality water from the Gunnison River during the irrigation season and, thus, less dilution capability would exist, Downstream from Montrose, additional Gunnison River water would be present to dilute sediments and other pollutants, Salt. loading to the river would be reduced by the hydropower project through lining the AB Lateral and reducing flow in the South Canal, SOILS A.~D VEGETATION No significant changes in soils cr vegetation are projected under the no-action alternative, Under 'the development alternatives, vegetation and soil disturbance would occu~ in construction areas, Disturbed areas would be restored and reseeded, A total of approximately 11 a,cres of wetlands would be lost directly, This acreage would be replaced by creating a wetland area near the powerplant and also by vegetation planting along the Uncompahgre River, Indirect effects are also discussed in the FEIS, Lower flows in the Gunnison River would allow the establishment of additional riparian and wetland vegetation, However, the scouring of vegetation .would occur during high flow periods as S - 10