Valley Project, built by the Bureau of Reclamation during the 1940s and 1950s. The southern portion of the CVP, which is relevant here, includes two divisions. The Friant Division's dominant features are the Friant Dam on the San Joaquin River and the Friant-Kern Canal, which runs 150 mi (240 km) south to a point near Bakersfield. This division delivers an average of 1.5 million acre-feet (1.8 million ML) annually to approximately 15,000 farms on the east side of the San Joaquin Valley. The San Luis Division includes the San Luis Reservoir and a portion of the California Aqueduct, both of which are jointly used by the CVP and the state of California. This division services an area on the western side of the San Joaquin Valley, delivering approximately 1.2 million acre-feet (1.4 million ML) annually.

Surface waters are also imported to the San Joaquin Valley from the Sacramento basin by the State Water Project; this water is delivered to the western side of the San Joaquin Valley from the delta of the Sacramento and San Joaquin rivers via the California Aqueduct. The aqueduct, which lies on the western side of the valley, ultimately traverses the Tehachapi Mountains and enters the Los Angeles basin.

The water supply facilities of the San Joaquin Valley, as well as those of the state as a whole, are interconnected in a variety of ways. The Cross Valley Canal connects the California Aqueduct with the Friant-Kern Canal and allows water to be delivered from the Sacramento-San Joaquin delta to users in the Friant Division. The Kern River-California Aqueduct Intertie allows water flowing in the lower reaches of the Kern River to be put into the California Aqueduct and made available to users along the aqueduct. Ground water recharge basins are operated throughout the eastern and southern portions of the San Joaquin Valley and permit surface and ground water supplies to be managed conjunctively. These facilities, together with numerous smaller, more localized interconnections, provide a physical infrastructure that allows the water delivery systems of the valley to be managed in a highly integrated fashion.

The existence of physically integrated water delivery systems and the ability of different irrigation districts to exchange water from different sources mean that water can be moved between virtually any two points in the valley. In addition, water can be obtained from or transferred to most locations in the state with the exception of the North Coast basin and some central coast areas. Thus, except in very rare cases, water transfers in California need not be constrained by the absence of transport facilities. This contrasts with circumstances in other states, such as Arizona, where the potential for water transfers is crucially conditioned by the availability of conveyance facilities.