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The Rampart Dam or Rampart Canyon Dam was a project proposed in 1954 by the U.S. Army Corps of Engineers to dam the Yukon River in Alaska for hydroelectric power. The project was planned for Rampart Canyon (also known as Rampart Gorge) just southwest of the village of Rampart, Alaska and about west-northwest of Fairbanks, Alaska. The resulting dam would have created a lake roughly the size of Lake Erie, making it the largest man-made reservoir in the world. The plan for the dam itself called for a concrete structure high with a top length of about . The proposed power facilities would have consistently generated between 3.5 and 5 gigawatts of electricity, based on the flow of the river as it differs between winter and summer. Though supported by many politicians and businesses in Alaska, the project was canceled after objections were raised. Native Alaskans in the area protested the threatened loss of nine villages that would be flooded by the dam. Conservation groups abhorred the threatened flooding of the Yukon Flats, a large area of wetlands that provides a critical breeding ground for millions of waterfowl. Fiscal conservatives opposed the dam on the grounds of its large cost and limited benefit to Americans outside Alaska. Because of these objections, United States Secretary of the Interior Stewart Udall formally opposed construction of the dam in 1967, and the project was shelved. The U.S. Army Corps of Engineers nevertheless completed its engineering study of the project in 1971, and the final report was released to the public in 1979. In 1980, U.S. President Jimmy Carter created the Yukon Flats National Wildlife Sanctuary, which formally protected the area from development and disallowed any similar project. == Site == From its headwaters in the Coast Mountains, the Yukon River flows northwest, across the Yukon–Alaska border, until it intersects the Porcupine River at the settlement of Fort Yukon. At that point, the river turns west and southwest, flowing through the Yukon Flats, a low-lying wetland area containing thousands of ponds, streams, and other small bodies of water. As the river flows southwest, it intersects the Tanana and Koyukuk rivers before looping south, then north into Norton Sound in the Bering Sea.〔U.S. Army Corps of Engineers, Alaska District. ''Data on Rampart Canyon Project Studies''. Anchorage, Alaska. May 27, 1961. p. 3〕〔Corps of Engineers, p. A-1〕 During the river's flow through eastern Alaska, and before it intersects the Tanana River, the Yukon flows through the Central Plateau region of Alaska. During the millions of years of its flow, it has cut through ridges, forming canyons in some places near its juncture with the Tanana.〔Corps of Engineers, p. 199.〕 One of the deepest of these canyons is known as Rampart Gorge, or Rampart Canyon. The gorge is located downstream of the village of Rampart, upstream of the village of Tanana, and immediately downstream from the mouth of Texas Creek.〔 It is named for the nearby village of Rampart, Alaska, a former gold-mining community now home to subsistence fishermen.〔U.S. Geological Survey, ("Feature Detail Report for: Rampart Gorge" ), Geographic Names Information System. Retrieved January 19, 2009.〕 At the proposed dam site, the river is wide and has an elevation of above sea level. On the south bank, the land rises sharply to a ridge high. North of the river, the bank rises to before ascending gradually northwest to the Ray Mountains.〔 Below the surface of the ground are patches of permafrost, and the area is seismically active.〔Corps of Engineers, p. 200〕 An earthquake measuring 6.8 on the Richter Scale struck the region in 1968,〔Bowling, Sue Ann. ("Earthquake Forecasting and the Mogi Doughnut" ), Alaska Geophysical Institute. March 28, 1988. Retrieved February 1, 2009.〕 and a 5.0 earthquake hit the area in 2003.〔U.S. Geological Survey. ("Rampart, Alaska Earthquake" ), USGS.gov. April 2, 2003. Retrieved February 1, 2009.〕 Geologically, igneous rock predominates, and quartz can be seen in places.〔Corps of Engineers, pp. 198–201〕 Hydrologically, the portion of the river upstream of the proposed dam drains about . On average, the Yukon flows at a rate of through the canyon, with the fastest flow occurring in the later part of May and the first part of June, and the slowest flow occurring after the river has frozen over. This occurs no later than early November and lasts until mid April.〔U.S. Army Corps of Engineers, Alaska District. ''Data on Rampart Canyon Project Studies''. Anchorage, Alaska. May 27, 1961. p. 4〕 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「Rampart Dam」の詳細全文を読む スポンサード リンク
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