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Show CEA Report Purpose of and Need for Action LEN CANYON DAM was built as the centerpiece of the Colorado River Storage Act. Its main purpose was to store water in the upper basin for delivery to the lower basin in accordance with the Colorado River Compact. The reservoir was to provide an adequate supply of water during drought years. Additional objectives were flow regulation, reclamation of arid land, and power generation. Today we must ask ourselves if the dam is effectively meeting its original purposes, and if these original goals are consistent with what we now know about the environmental consequences of dams. Large dams along the Colorado River have compromised the ecological integrity of the Colorado River system. Sediment and water previously supplied to the Grand Canyon from Glen Canyon have been altered or cut off as a result of the dam. Without these critical supplies, the historical sustainability of Grand Canyon will continue to be compromised. In addition to impacts in Grand Canyon, the health of the Colorado River Delta is dependent upon management of the river upstream. Current management practices have desiccated and compromised the Delta and upper Sea of Cortez. The flooding of Glen Canyon is considered by many to be a tragic environmental loss. Yet during the late 1950s, when construction of Glen Canyon Dam began, there were few environmental laws. Nor was there an opportunity for public debate regarding dam construction and water management. Today we have the Endangered Species Act of 1973, which was designed to restore and protect endangered species, such as those which struggle for survival in the radically altered, post dam environment. The Clean Water Act of 1972 mandates that actions be taken to mitigate or eliminate impacts to water quality. Cultural preservation laws, such as the Archaeological and Historic Preservation Act, are in place to protect archaeological and cultural resources like those which were inundated by Powell reservoir. Most would agree that, with these laws in place and with the current level of environmental awareness and involvement of the public, Glen Canyon Dam could certainly not be built today. Following its completion in 1963, Glen Canyon Dam was operated to maximize power generation and flatwater recreational activities upstream, with little thought given to downstream impacts on the Colorado River through Grand Canyon National Park. These impacts were profound. Water released through the turbines fluctuated wildly in order to meet peak power demand, and could vary between 1,000 and 31,500 cubic feet per second ( CFS) within a matter of hours. The clear, sediment- hungry water released by the dam eroded beaches throughout Grand Canyon. By the 1980s, public outcry over the devastating impacts to the riparian habitat within Grand Canyon National Park reached a peak. Responding to public demand, the Secretary of the Interior directed the BOR to conduct an EIS on operations of Glen Canyon Dam. This EIS included a thorough and rigorous examination of the impacts of the dam. It was limited in scope, however, as the BOR refused to consider dam decommissioning within the range of alternatives. The public was deprived of taking part in the decision as to whether or not the environmental consequences of maintaining Glen Canyon Dam outweighed the benefits provided by the reservoir. Periodic flow management measures, resulting from the 1996 EIS, are not a long term solution to the problems resulting from the dam. In order to restore the ecological integrity of the river, we need to manage the entire system. The focus of this CEA is to reassess decisions previously made about the dam and water management through scientific examination of the impacts of Glen Canyon Dam, and the potential impacts of decommissioning. The concept of water management in the west is changing as society and demographics of this region change. We need to examine how best to manage our water resources in light of our current knowledge, and the needs of humans and the environment. page 4 |
