|
Bridge Canyon Dam, also called Hualapai Dam, was a proposed dam in the lower Grand Canyon of the Colorado River, in northern Arizona in the United States. It would have been located near Bridge Canyon Rapids in an extremely rugged and isolated portion of the canyon, downstream of Lee's Ferry and at the uppermost end of Lake Mead. First proposed in the 1920s, the project was seriously considered by the U.S. Bureau of Reclamation for a period of over twenty years from the early 1950s to 1968. If built, the dam would have stood high, forming a reservoir stretching more than ninety miles (150 km) upstream, including thirteen miles (21 km) along the border of Grand Canyon National Park. The dam would serve mainly for hydropower production in conjunction with several others further upstream including Marble Canyon Dam, on the Colorado, Green and other rivers. Due to its enormous potential for environmental destruction and the dwindling flows of the Colorado River, the project stalled in 1968 after years of public opposition. However, the location is considered one of the best remaining sites for a large dam in the western United States. ==Background== Bridge Canyon Dam was first seriously considered in the mid-20th century as part of the Pacific Southwest Water Plan, which aimed to deliver water from the Colorado River to central Arizona in order to allow that state to utilize its full allotment in the Colorado River Compact. The proposed project would involve a canal running from Lake Havasu on the Colorado River to supply metro Phoenix and the surrounding irrigated lands. A pair of dams within the Grand Canyon would provide the hydroelectric power necessary to pump the water uphill along the canal's course. One of these dams would be located at the lower end of Marble Canyon and was known as Marble Canyon or Redwall Dam; the other, known as Bridge Canyon Dam or Hualapai Dam, would be situated in Bridge Canyon in Lower Granite Gorge. The two dams would generate a combined 12.2 billion kilowatt hours (KWh) annually with a total installed capacity between 2000 and 3000 megawatts (MW). In the 1940s, Reclamation began investigating potential sites for a dam in the lower Grand Canyon near the river's confluence with Diamond Creek, upstream of Lake Mead. A small tent city was erected along the Colorado River near Bridge Canyon, complete with "a tar-paper cook shack with tables, a walk-in refrigerator attached, and tents or sleeping accommodations for the men… a small generating plant which furnished lights and fans for the swamp-type air conditioners which were a necessity in this canyon." The site was only accessible by a boat trip up the Colorado River from Lake Mead, and was plagued by torrid heat, poor access, floods and long working hours.〔 After more than four potential damsites were investigated, the best one was found at a location called the "Lower Gneiss" site below the confluence of Gneiss Canyon, a small tributary, and northwest of the small town of Peach Springs. The dam was proposed as a concrete arch-gravity structure high above its foundations, with a hydraulic head from . It would raise the water behind it for upstream to an elevation of just below the mouth of Kanab Creek. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bridge Canyon Dam」の詳細全文を読む スポンサード リンク
|