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The Columbia Basin Project (or CBP) in Central Washington, USA, is the irrigation network that the Grand Coulee Dam makes possible. It is the largest water reclamation project in the United States, supplying irrigation water to over of the large project area, all of which was originally intended to be supplied and is still classified as irrigable and open for the possible enlargement of the system. Water pumped from the Columbia River is carried over of main canals, stored in a number of reservoirs, then fed into of lateral irrigation canals, and out into of drains and wasteways.〔(【引用サイトリンク】publisher= United States Bureau of Reclamation )〕 ==History== The U.S. Bureau of Reclamation was created 1902 to aid development of dry western states. Central Washington's Columbia Plateau was a prime candidate—a desert with fertile loess soil and the Columbia River passing through. Competing groups lobbied for different irrigation projects; a Spokane group wanted a gravity flow canal from Lake Pend Oreille while a Wenatchee group (further south) wanted a large dam on the Columbia River, which would pump water up to fill the nearby Grand Coulee, a formerly-dry canyon-like coulee. After thirteen years of debate, President Franklin D. Roosevelt authorized the dam project. Construction of Grand Coulee Dam began in 1933 and was completed in 1942. Its main purpose of pumping water for irrigation was postponed during World War II in favor of electrical power generation that was used for the war effort. Additional hydroelectric generating capacity was added into the 1970s. The Columbia River reservoir behind the dam was named Franklin Delano Roosevelt Lake in honor of the president. The irrigation holding reservoir in Grand Coulee was named Banks Lake. After World War II the project suffered a number of setbacks. Irrigation water began to arrive between 1948 and 1952, but the costs escalated, resulting in the original plan, in which the people receiving irrigation water would pay back the costs of the project over time, being repeatedly revised and becoming a permanent water subsidy. In addition, the original vision of a social engineering project intended to help farmers settle on small landholdings failed. Farm plots, at first restricted in size, became larger and soon became corporate agribusiness operations.〔 The original plan was that a federal agency similar to the Tennessee Valley Authority would manage the entire system. Both the Bureau of Reclamation and the Department of Agriculture sought to gain control as the primary administrative agency, and both pressed their own plan for doing so. The rivalry between them was ultimately so paralyzing that a power vacuum was created. Neither agency gained control and large private interests prevailed instead. As a result, the original vision lost its cohesive focus and corporate interests gained as the main beneficiaries.〔 The determination to finish the project's plan to irrigate the full waned during the 1960s. The estimated total cost for completing the project had more than doubled between 1940 and 1964, it had become clear that the government's financial investment would not be recovered, and that the benefits of the project were unevenly distributed and increasingly going to larger businesses and corporations. These issues and others dampened enthusiasm for the project, although the exact motives behind the decision to stop construction with the project about half finished are not known.〔 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「Columbia Basin Project」の詳細全文を読む スポンサード リンク
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