River Resource Management in the Grand Canyon (1996) / Chapter Skim
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1 INTRODUCTION AND BACKGROUND
1 INTRODUCTION AND BACKGROUND
Pages 11-23
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From page 11... ...
Descending from almost 3 miles above sea level near Long's Peak in Colorado and in the Wind River range of Wyoming, the Colorado River's sources quickly reach flatter topography in Utah and Colorado while still more than a mile above sea level. The river continues its plunge toward sea level through canyons that ultimately trench the plateau to a depth of more than a mile.
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From page 12... ...
The dams for these two reservoirs, which produce most of the electricity and hold most of the water of the Colorado River, together inundate over 300 miles of the river. While the two dams are of similar size and provide many of the same benefits, Glen Canyon Dam, which impounds Lake Powell, is of particular importance because it holds back the Colorado River in front of the Grand Canyon (Figure 1.1~.
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From page 14... ...
The Colorado River Storage Project Act listed beneficial use of water, reclamation of arid and semiarid lands, and control of floods as primary purposes of the Glen Canyon Dam. The act also mentioned hydroelectric power but only as an "incident" of other specifically mentioned purposes.
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From page 15... ...
The broadened purposes for operation of the dam were reconfirmed in 1992 with the Grand Canyon Protection Act, which cited the need to "mitigate adverse impacts to and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established, including, but not limited to natural and cultural resources and visitor use." Several forces were behind Congress' decision to intervene in the operation of Glen Canyon Dam. The most important change in the legal frame of reference was the Endangered Species Act (ESA)
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From page 16... ...
The BOR was predisposed to identify strongly with WAPA's priorities. Not only had the bureau been directed in the original authorizing legislation for Glen Canyon Dam to produce maximum revenue from power, it had also assumed that revenue from the dam would sustain its other projects in the Colorado River Basin.
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From page 17... ...
Fish and Wildlife Service, and the Arizona Game and Fish Department but were later broadened to include Indian tribes with territorial or cultural interests in the Grand Canyon. Much of the push to extend and broaden GCES came from the resource management agencies that, without the BOR, had no means of financing extensive studies of the resources below Glen Canyon Dam.
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From page 18... ...
NRC sponsored Grand Canyon symposium 9. Start of experimental flows for Glen Canyon Dam 10.
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From page 19... ...
This requirement was later embodied in the Grand Canyon Protection Act of 1992, which states: ·ong-term monitoring of Glen Canyon Dam shall include any necessary research and studies to determine the effect of the Secretary's actions under section 1204 (c) on the natural, rec reational, and cultural resources of Grand Canyon National Park and Glen Canyon National Recreation Area.
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From page 20... ...
The interim flows are an important landmark in the history of Glen Canyon Dam because they signify the decision of the BOR to modify its operation of the dam in a significant way to protect environmental resources, atthe cost of reduced efficiency in power marketing. In evaluating interim flows, GCES scientists had the important responsibility of recommending operational strategies that would be the most likely to protect or optimize environmental resources over the short term.
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From page 21... ...
While the results of the GCES are of pressing relevance to the protection of resources in the Grand Canyon, they also serve as an excellent case study of the federal government's efforts to use ecosystem science as a guide to environmental management.
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From page 23... ...
1993. Operation of Glen Canyon Dam Colorado River Storage Project, Arizona.
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