<Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2014) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2014) (Learn how and when to remove this template message) </Td> </Tr> <P> Water use in California is divided into approximately 51% for environmental uses, 39% agricultural use and 11% urban uses, though that varies considerably between regions and between wet and dry years . Solely relying on these statewide volumes is controversial because they don't consider the fact that most of the volume of water used for environmental purposes includes flows down Wild and Scenic Rivers in the North Coast where there is no practical way to recover it for either agricultural or urban use because it lacks many connections to the statewide water supply system . It also doesn't factor in the amount of water required to keep salty water from the Pacific Ocean from intruding into the Delta beyond a certain small concentration . Otherwise, "reduced water quality resulting from large amounts of salt water drawn into the Delta could shut down the export pumps that supply fresh water to agriculture and cities ." </P> <P> Around 75% of California's water supply comes from north of Sacramento, while 80% of the water demand occurs in the southern two - thirds of the state . The Sacramento - San Joaquin River Delta Estuary located between San Francisco Bay and Sacramento receives about 40% of California's total precipitation and 50% of its total streamflow . It is a critical hub used by the federal Central Valley Project and California State Water Project to connect water collected and stored in the north regions of the state with aqueducts and canals that transport it to users in the North Bay, South Bay, East Bay, and Greater Southern California . In a typical year, about 10.8 million acre - feet are exported from the Delta: 67% is delivered by the Central Valley Project, 26% by the State Water Project and the remainder to other federal water project users . Those flows are greatly reduced in drought years . About 16.5 million acre - feet of water entering the Delta in a typical year flows through the Delta into San Francisco Bay, including 6.3 million acre - feet in governmentally mandated environmental flows; 22.4 million acre - feet is used for other environmental purposes, and 1.6 million acre - feet supplies water to managed wetlands and wildlife preserves . </P>

What are the main uses of water in california