SPRING VALLEY - Against the backdrop of a half-filled Sweetwater Reservoir Gov. Arnold Schwarzenegger made a pitch Tuesday for a $5.9 billion blueprint to expand the water supply of a state expected to have 60 million residents by 2050.

The governor's stop in San Diego County was the fourth he has made over the last several days, in a bid to drum up political support for his plan for a pair of new reservoirs bigger than Diamond Valley Lake, several underground storage projects and increased conservation measures. He is trying to negotiate an agreement with legislative leaders, some of whom have traditionally been averse to building dams.

Earlier, the governor held news conferences in Long Beach, the Central Valley and at a site overlooking the Sacramento-San Joaquin Delta, where critical delivery systems that serve Southern California have shut down in recent weeks.

"I've been traveling up and down the state to put the spotlight on our water problems," Schwarzenegger said. "We haven't built a reservoir in the last 30 years. … We don't have enough water storage."

Schwarzenegger cited the Sweetwater Reservoir, fed almost entirely by imported water from the Colorado River and Northern California, as an example of California's dwindling supplies. As a consequence of an eight-year-old drought in the Colorado River basin and exceptionally dry conditions across California, he said the state is in a particularly vulnerable position.

"Throughout most of Southern California, this was the driest year in history," he said. "And all of this was just from one dry winter. If we have another, it will be disastrous."

Schwarzenegger suggested the state needs more and bigger reservoirs to help sustain Californians during dry periods.

His comments were echoed by several local dignitaries who appeared with him. One was Eric Larson, San Diego County Farm Bureau executive director.

"If we are going to survive the dry years, we need to harvest the wet years," Larson said.

Gary Arant, general manager of the Valley Center Municipal Water District, attended the conference. In a brief interview later, he said the drought is stretching North County supplies.

"We're on the edge right now," Arant said. "Our water supply is very tenuous."

The governor's plan calls for setting aside $4.5 billion for boosting the supply; $1 billion for restoring the fragile Sacramento-San Joaquin Delta, and building a canal around it; $250 million for restoration projects on the Klamath, San Joaquin and Sacramento rivers and the Salton Sea; and $200 million for conservation programs.

The governor acknowledged that a new delta canal could be a tough sell in the San Francisco Bay Area, where such a proposal two decades ago raised suspicions that Southern California was trying to grab Northern California's water.

But, he said, "Times change."

Joe Grindstaff, deputy secretary for water policy in the state Resources Agency in Sacramento, said after the news conference that the governor would like to build two new reservoirs, "either one of which would be bigger than Diamond Valley Lake" in Southwest Riverside County.

Grindstaff said the governor also would like to expand an existing reservoir in Contra Costa County.

The plan would be funded primarily by a $3.9 billion general obligation bond that California voters could face in February. Another $2 billion would come from bonds backed by water customers.

- Contact staff writer Dave Downey at (760) 740-5442 or ddowney@nctimes.com.