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<br />. <br /> <br />,.. ~ _ .~'i'..".~.. <br /> <br />"~-' <br /> <br />U.S. seeks to warm Colorado River <br /> <br />Page 2 of3 <br /> <br />of the Colorado River, they often die of thermal shock, Wirth <br />said. <br /> <br />Rob Smith, Southwest representative of the Sierra Club, <br />praised efforts to try to help native Arizona fish, 19 of which <br />are listed as endangered or threatened with extinction. <br /> <br />But Smith cautioned that if the waters get too warm, it could <br />invite predatory non-native fish in Lake Mead to move <br />upstream. <br /> <br />"The trick is to get the water warm enough for the chub ... but <br />not make it so warm that other fish will come upstream and eat <br />them," Smith said. <br /> <br />Before construction of Glen Canyon Dam, temperatures of the <br />Colorado River in the Grand Canyon ranged from near <br />freezing in winter to about 78 degrees in the summer. <br /> <br />Since construction of the dam, the cold, clear releases have <br />resulted in a world-class rainbow trout fishing area between <br />the dam and Lees Ferry. <br /> <br />However, the water from the dam is slightly colder than <br />optimum for the trout, too, Wirth said. Increasing the <br />temperature of the water should also help trout, he said. <br /> <br />Similar temperature modifications have been made to Flaming <br />Gorge Dam in Utah, the Shasta Dam in California and the <br />Hungry Horse Dam in Montana. <br /> <br />Warmer releases from Flaming Gorge into the Green River, a <br />large tributary of the Colorado River, resulted in greater <br />numbers oftrout and endangered Colorado squawfish in <br />downstream Ladore Canyon. <br /> <br />The proposed temperature modification for Glen Canyon Dam <br />is one of the final outcomes of the 1992 Grand Canyon <br />Protection Act, pushed by Sen. John McCain, R-Ariz. <br /> <br />That act resulted in more even releases from the dam, which <br />lessened the possibilities of beach erosion, destruction of <br />artifacts and wildlife habitat damage. The act also resulted in <br />an 1995 Environmental Impact Statement, which cleared the <br />way for beach-building artificial floods the following year. <br /> <br />One of the requirements of the massive environmental report <br />was the development of temperature modifications at Glen <br />Canyon Dam. <br /> <br />*** <br /> <br />Steve Yozwiak can be reached at 444-8810 or at <br /> <br />http://www.azcentral.comlnews/0126glencanyon.shtml <br /> <br />1/26/99 <br />