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The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest state-owned water and power utilities in the world, providing drinking water for more than 23 million people and generating an average of 6500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5100 GWh. The SWP collects water from rivers in Northern California and redistributes it to the water-scarce but populous south through a network of aqueducts, pumping stations and power plants. About 70% of the water provided by the project is used for urban areas and industry in Southern California and the San Francisco Bay Area, and 30% is used for irrigation in the Central Valley. To reach Southern California, the water must be pumped over the Tehachapi Mountains, with at the Edmonston Pumping Plant alone, the highest single water lift in the world. The SWP shares many facilities with the federal Central Valley Project (CVP), which primarily serves agricultural users. Water can be interchanged between SWP and CVP canals as needed to meet peak requirements for project constituents. The SWP provides estimated annual benefits of $400 billion to California's economy. Since its inception in 1960, the SWP has required the construction of 21 dams and more than of canals, pipelines and tunnels, although these constitute only a fraction of the facilities originally proposed. As a result, the project has only delivered an average of annually, as compared to total entitlements of . Environmental concerns caused by the dry-season removal of water from the Sacramento–San Joaquin River Delta, a sensitive estuary region, have often led to further reductions in water delivery. Work continues today to expand the SWP's water delivery capacity while finding solutions for the environmental impacts of water diversion. ==History== The original purpose of the project was to provide water for arid Southern California, whose local water resources and share of the Colorado River were insufficient to sustain the region's growth. The SWP was rooted in two proposals. The United Western Investigation of 1951, a study by the U.S. Bureau of Reclamation, assessed the feasibility of interbasin water transfers in the Western United States. In California, this plan contemplated the construction of dams on rivers draining to California's North Coast – the wild and undammed Klamath, Eel, Mad and Smith River systems – and tunnels to carry the impounded water to the Sacramento River system, where it could be diverted southwards.〔Agee, p. 174〕 In the same year, State Engineer A.D. Edmonston proposed the Feather River Project, which proposed the damming of the Feather River, a tributary of the Sacramento River, for the same purpose. The Feather River was much more accessible than the North Coast rivers, but did not have nearly as much water. Under both of the plans, a series of canals and pumps would carry the water south through the Central Valley to the foot of the Tehachapi Mountains, where it would pass through the Tehachapi Tunnel to reach Southern California.〔Reisner, p. 269〕 Calls for a comprehensive statewide water management system (complementing the extensive, but primarily irrigation-based Central Valley Project) led to the creation of the California Department of Water Resources in 1956. The following year, the preliminary studies were compiled into the extensive California Water Plan, or Bulletin No. 3. The project was intended for "the control, protection, conservation, distribution, and utilization of the waters of California, to meet present and future needs for all beneficial uses and purposes in all areas of the state to the maximum feasible extent." California governor Pat Brown would later say it was to "correct an accident of people and geography". The diversion of the North Coast rivers was abandoned in the plan's early stages after strong opposition from locals and concerns about the potential impact on the salmon in North Coast rivers. The California Water Plan would have to go ahead with the development of the Feather River alone, as proposed by Edmonston. The Burns-Porter Act of 1959 provided $1.75 billion of initial funding through a bond measure. Construction on Stage I of the project, which would deliver the first of water, began in 1960. Northern Californians opposed the measure as a boondoggle and an attempt to steal their water resources. In fact, the city of Los Angeles – which was to be one of the principal beneficiaries – also opposed the project; locals saw it as a ploy by politicians in the other Colorado River basin states to get Los Angeles to relinquish its share of the Colorado River. Historians largely attribute the success of the Burns-Porter Act and the State Water Project to major agribusiness lobbying, particularly by J.G. Boswell II of the J.G. Boswell cotton company. The bond was passed on an extremely narrow margin of 174,000 out of 5.8 million ballots cast. In 1961, ground was broken on Oroville Dam, and in 1963, work began on the California Aqueduct and San Luis Reservoir. The first deliveries to the Bay Area were made in 1962, and water reached the San Joaquin Valley by 1968. Due to concerns over the fault-ridden geography of the Tehachapi Mountains, the tunnel plan was scrapped; the water would have to be pumped over the mountains' crest. In 1973, the pumps and the East and West branches of the aqueduct were completed, and the first water was delivered to Southern California. A Peripheral Canal, which would have carried SWP water around the vulnerable and ecologically sensitive Sacramento–San Joaquin River Delta, was rejected in 1982 due to environmental concerns. The Coastal Branch, which delivers water to coastal central California, was completed in 1997.〔 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「California State Water Project」の詳細全文を読む スポンサード リンク
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