<Tr> <Td_colspan="2"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Central Valley Project (CVP) is a federal water management project in the U.S. state of California under the supervision of the United States Bureau of Reclamation (USBR). It was devised in 1933 in order to provide irrigation and municipal water to much of California's Central Valley--by regulating and storing water in reservoirs in the water - rich northern half of the state, and transporting it to the water - poor San Joaquin Valley and its surroundings by means of a series of canals, aqueducts and pump plants, some shared with the California State Water Project (SWP). Many CVP water users are represented by the Central Valley Project Water Association . </P> <P> In addition to water storage and regulation, the system has a hydroelectric capacity of over 2,000 megawatts, and provides recreation and flood control with its twenty dams and reservoirs . It has allowed major cities to grow along Valley rivers which previously would flood each spring, and transformed the semi-arid desert environment of the San Joaquin Valley into productive farmland . Freshwater stored in Sacramento River reservoirs and released downriver during dry periods prevents salt water from intruding into the Sacramento - San Joaquin Delta during high tide . There are eight divisions of the project and ten corresponding units, many of which operate in conjunction, while others are independent of the rest of the network . California agriculture and related industries now directly account for 7% of the gross state product for which the CVP supplied water for about half . </P>

What is the irrigation system for the central valley in california