The Central Valley Project
Army engineers first contemplated a comprehensive approach to irrigating the Central Valley for agricultural use in 1873. Federal and state agencies then contributed to the unfolding plan, and in 1931 the state's Division of Water Resources presented a comprehensive proposal to the state legislature.
The plan called for the state to sell revenue bonds to finance the construction of facilities for the storage and transport of water in the Central Valley, but the Great Depression impeded the sale of those bonds. The federal government took control of the project, which is now operated by the U.S. Bureau of Reclamation. Construction of the project's various dams and canals began in 1937.
Although the original purpose of the Central Valley Project was to provide for irrigation of Central Valley farmland, it now includes facilities to generate power and to improve flood control and navigation, projects to enhance water quality and provide for recreation, and measures to restore fish and wildlife habitats. The Central Valley Project involves 20 dams and reservoirs, 11 power plants, and some 500 miles of canals. It is a vital source of water for three-quarters of the irrigated land in California.