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}} Bonneville Lock and Dam consists of several run-of-the-river dam structures that together complete a span of the Columbia River between the U.S. states of Oregon and Washington at River Mile 146.1. The dam is located east of Portland, Oregon, in the Columbia River Gorge. The primary functions of Bonneville Lock and Dam are electrical power generation and river navigation. The dam was built and is managed by the United States Army Corps of Engineers. Electrical power generated at Bonneville is distributed by the Bonneville Power Administration. Bonneville Lock and Dam is named for Army Capt. Benjamin Bonneville, an early explorer credited with charting much of the Oregon Trail. The Bonneville Dam Historic District was designated a National Historic Landmark District in 1987.〔 ==History== In 1896, prior to this damming of the river, the Cascade Locks and Canal were constructed, allowing ships to pass the Cascades Rapids, located several miles upstream of Bonneville. Prior to the New Deal, development of the Columbia River with flood control, hydroelectricity, navigation and irrigation was deemed as important. In 1929, the US Army Corps of Engineers published the 308 Report that recommended 10 dams on the river but no action was taken until the Franklin D. Roosevelt administration and the New Deal. During this period America was in the Great Depression, and the dam's construction provided jobs and other economic benefits to the Pacific Northwest. Inexpensive hydroelectricity gave rise to a strong aluminum industry in the area. With funding from the Public Works Administration in 1934, two of the larger projects were started, the Grand Coulee Dam and the Bonneville Dam. 3,000 workers in non-stop eight-hour shifts, from the relief or welfare rolls, were paid 50-cents an hour for the work on the dam and raising local roads for the reservoir.〔http://www.u-s-history.com/pages/h1792.html General Interest, Built 1934〕 To create the Bonneville Dam and Lock, The Army Corps of Engineers first built one of the largest scale models in history of the proposed dam, the section of river it was to be located on, and its various components to aid in the study of the construction.〔("Model of Bonneville Dam Aids in Study of River" ) ''Popular Mechanics'', April 1935〕 First a new lock and a powerhouse was constructed which were on the south (Oregon) side of Bradford Island, and a spillway on the north (Washington) side. Cofferdams were built to block half of the river and clear a construction site where the foundation could be reached. These projects, part of the Bonneville Dam were completed in 1937.〔http://www.ohs.org/education/oregonhistory/historical_records/dspDocument.cfm?doc_ID=00056187-B22F-1E35-925B80B05272006C Workers at Bonneville Dam〕 Both the cascades and the old lock structure were submerged by the Bonneville Reservoir, also known as Lake Bonneville, the reservoir that formed behind the dam. The original navigation lock at Bonneville opened in 1938 and was, at that time, the largest single-lift lock in the world. Although the dam began to produce hydroelectricity in 1937, Commercial electricity began its transfer from the dam in 1938.〔 A second powerhouse (and dam structure) was started in 1974 and completed in 1981. The second powerhouse was built by widening the river channel on the Washington side, creating Cascades Island between the new powerhouse and the original spillway. The combined electrical output of the two power houses at Bonneville is now over 1,000 megawatts. Despite its world record size in 1938, Bonneville Lock became the smallest of seven locks built subsequently at different locations upstream on the Columbia and Snake rivers; eventually a new lock was needed at Bonneville. This new structure was built on the Oregon shore, opening to ship and barge traffic in 1993. The old lock is still present, but is no longer used. 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「Bonneville Dam」の詳細全文を読む スポンサード リンク
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