Lakes Spill but Supplies Remain Low : Water: Officials say underground basins remain overdrawn and one good rain hardly makes a difference.

Ventura County lakes are spilling over, ground-water levels are up and water usage among farmers and residents is down because of last month’s record rainfall.

So why aren’t county water officials rejoicing?

For one thing, they say, only a fraction of the rainwater that fell was saved because there was no place to store it.

Moreover, they add, the county’s deepest and most heavily used underground basins have been overdrawn for the past 50 years and one good rain a year hardly makes a difference. “We have plenty of water for this year,” said Lowell Preston, who manages the county’s water resources division. “But we’ve got to make sure that everyone understands that we live in a desert and the problem is not going to go away.”

Preston noted, however, that there are several major water storage and reclamation projects in the works that could help the county keep pace with a growing population.

Projects in the planning or development stage:

* The Calleguas Municipal Water District, which supplies water to about 500,000 residents countywide, is working on a plan to store millions of gallons of water in a giant underground basin near Moorpark that could be used in emergencies.

* Thousand Oaks is planning to build an expanded, high-tech waste water treatment plant that will sell reclaimed water to county water districts, and this in turn will reduce pumping from overdrawn basins.

* Oxnard is studying a proposal to build a water-reclamation plant by the end of the century that could be used to restore ground-water supplies and safeguard against seawater intrusion in underground basins.

* And United Water Conservation District, which replenishes underground water supplies for much of the west county, will begin converting an abandoned gravel mining pit into a reservoir this week that will help replenish water levels in the upper Oxnard Aquifer.

These and other smaller projects combined could provide tens of thousands of additional acre-feet of water to the county annually, Preston said. An acre-foot of water is enough to supply two families for a year.

“Every one of these projects is a little piece that can make our system work in the end,” Preston said. “At least it will help us make up for what we’ve overused in the past.”

Calleguas General Manager Don Kendall, whose district provides 100,000 acre-feet of imported water to the county each year, said saving more water would also help prepare for natural disasters. A single pipeline connects the county to the state aqueduct in the San Fernando Valley.

“It’s not a drought that’s going to get us,” Kendall said. “It’s an earthquake.”

After the Northridge quake, Kendall said Calleguas was cut off from its water supply in Los Angeles County for nearly a week while cracks in its water line were repaired. To increase its storage capability, Kendall said, Calleguas is proposing to drill 25 to 30 wells on ranchland near Moorpark and inject water into the Fox Canyon Aquifer. He said the district hopes to store 100,000 acre-feet of water in the basin over a five-year period.

Calleguas has run into some opposition from landowners who fear that the agency’s $50-million water-storage project would only encourage more development.

But Kendall said promoting growth is not Calleguas’ motive.

“We’re not trying to increase our pipeline capability, we’re trying to pigeonhole water,” he said. “During the last drought we could have saved more water, but there was nowhere to put it.”

Preston, of the county’s water resources division, agreed.

“Calleguas’ project is very important to the county,” Preston said.

Meanwhile, Thousand Oaks is pushing ahead with its plans to build a $65-million water-reclamation plant to help meet its future water demands.

The city’s plans were stalled the past two years because of a legal battle with property owners who had come to depend on runoff from the city’s waste-water treatment plant, said Don Nelson, director of public works.