The state said Thursday it would cut water deliveries to their second lowest level ever, prompting warnings of water rationing for cities and less planting by farmers.
The Department of Water Resources announced it will deliver just 15 percent of the amount that local water agencies throughout California request every year. That marks the second lowest projection since the first State Water Project deliveries were made in 1962.
It could force farmers in the Central Valley to fallow fields and cities from the San Francisco Bay area to San Diego to impose mandatory water rationing.
The state's reservoirs are low after two years of dry weather and court-ordered restrictions on water pumping out of the Sacramento-San Joaquin Delta. This year, water agencies received just 35 percent of the water they requested.
Lake Oroville, California's second largest reservoir, is usually half full this time of year but is at just 30 percent capacity.
In Southern California, the Metropolitan Water District - the agency that supplies water to about half the state's population - has depleted more than a third of its water reserves. The agency's general manager, Jeff Kightlinger, said Californians must immediately reduce their water use to stretch what little water is available.
"We are preparing for the very real possibility of water shortages and rationing
The State Water Project delivers water to more than 25 million residents and 750,000 acres of farmland.
In 2006, water agencies received their full allotment, in part because of heavy rains and a thick Sierra snowpack that year. But last year, a federal court limited water pumping out of the delta to protect the threatened delta smelt.
Department of Water Resources Director Lester Snow said the bleak outlook underscores the governor's call to retool California's massive water storage and delivery system.
Gov. Arnold Schwarzenegger favors building more dams and designing a new way to funnel water through or around the environmentally fragile delta. The proposals have failed to gain traction in the Legislature.
"The governor has sounded the wake-up call, and the clock is ticking," Snow said in a statement.
Even with Thursday's dire projection, a wet winter could mean cities and farms ultimately get more water, said Ted Thomas, a spokesman for the state water department.
That was the situation in 1993, when the state promised contractors just 10 percent of their requests, the lowest initial projection on record. That later was revised to 100 percent after the state received heavy precipitation.
Unlike then, state and federal water agencies are under a court order to cut pumping from the delta because a federal judge last year ruled that the giant pumps were harming threatened fish.
"Even if we have a wet fall and winter, the water won't necessarily be available to us because deliveries are also being cut to protect fish in the delta," Laura King Moon, assistant general manager of the State Water Contractors, said in a statement. "We are anticipating drastically reduced water supplies, regardless of weather conditions."