County Lakes Overflowing but Ground-Water Supplies Hurting

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.

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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.

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“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.

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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. “It’s the kind of farsighted thinking we need if we’re ever going to have a more permanent supply of water.”

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.

In addition to supplying more water to the city, the new plant, which is expected to be open in 1997, will also sell as much as 10,000 acre-feet of water a year to Calleguas. The district in turn will sell the water to member agencies in the west county, which will help reduce pumping of ground water.

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This is considered a critical part of the county’s water management plans since the county’s 2,000 farmers depend on ground water for their survival, officials said.

Indeed, the county’s giant agricultural industry, not its 700,000 residents, uses the bulk of its water supply. And ground-water basins provide two-thirds of the more than 425,000 acre-feet of water consumed here each year.

To help replenish its own ground-water supplies, Oxnard is studying a proposal to build an $80-million water-reclamation plant. The facility could save an estimated 20,000 acre-feet of water a year, officials said.

“What we’re trying to do is create a new water source in light of the ongoing drought,” said Mark Norris, manager of the city’s waste water management department. “We’re trying to look at this in the long term, to take a more farsighted approach.”

By replenishing depleted ground-water basins, Norris said the reclamation plant would also help preserve the quality of the city’s water. Over-pumping in the upper Oxnard Aquifer, he said, has allowed seawater to seep into some freshwater supplies near the ocean, making it unusable.

“The more pumping we have the more potential we have for seawater intrusion,” Norris said.

He said the city is studying various financing options for the reclamation plant, and a report should be ready for council review by the end of the year. Even if the city were to approve the plant, it would probably be at least five years before it could be operating.

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Work on another major project that will help stem the flow of seawater into fresh underground water basins is set to begin this week.

United Water Conservation District, an agency that replenishes seven ground-water basins in the county, will convert an abandoned gravel mining pit into a reservoir that can store up to 3,000 acre-feet of water annually, General Manager Fred Gientke said. The water will be used to help restore water levels in the Oxnard Aquifer.

This in turn will further limit pumping from the valuable Fox Canyon Aquifer beneath the Oxnard Plain. Fox Canyon, the largest underground basin in the county, has been overdrawn for the past 50 years by growers and cities that pumped more out each year than rainwater can replenish, Gientke said.

Because the overdraft has allowed seawater to penetrate the aquifer, United has been working for years to restore the ground-water supplies, Gientke said.

Since 1991, the agency has operated the Freeman Diversion Dam on the Santa Clara River at Saticoy, which diverts water into settling basins composed of sandy soil that filters the water into the aquifers under the Oxnard Plain.

The settling basins are the only portion of the Oxnard Plain where water can soak into the aquifers, Gientke said. The rest of the plain has clay layers underground that prevent rainwater from seeping in.

Since last month’s rains, which dropped a record 16 inches on the Oxnard Plain, the Freeman Dam has diverted about 600 acre-feet of water a day. A total of 31,000 acre-feet has been saved since the beginning of the rainy season in October.

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Gientke said United hopes to break its record of diverting 120,000 acre-feet during the 1992 floods. With three more months left in the rainy season, there is a good chance, he said.

But Preston of the county’s water resources division said even if United is able to divert more water, it will still be nowhere near the amount of water lost to the ocean.

To illustrate his point, Preston said that during 1993, one of the driest years on record, an estimated 420,000 acre-feet of water made its way down the Santa Clara River and into the ocean.

“Even in dry years, enough water goes out of the river to supply all of our water needs,” he said. “But there’s nowhere to put it.”

Ground-Water Basins

1. Upper Ojai Valley 2. Ojai Valley 3. Ventura River Valley 4. Mound Basin 5. Santa Paula Basin 6. Oxnard Plain Forebay 7. Oxnard Plain 8. Pleasant Valley 9. Las Posas Valley 10. Fillmore Basin 11. Piru Basin 12. Simi Valley 13. Arroyo Santa Rosa Valley 14. Conejo Valley