Accord Signed for County’s Largest Reservoir : Water: The $47-million underground system will ensure supplies for cities from Simi Valley to Oxnard in the event of a disaster.

A landmark agreement signed Tuesday will create the largest reservoir in Ventura County, ensuring a reliable water supply in cities from Simi Valley to Oxnard in the event of drought or earthquake.

The $47-million project near Moorpark will hold more water than Lake Casitas and nearly four times what Lake Piru holds. But don’t look for boat launches, tackle shops or campgrounds to spring up around it in the North Las Posas Basin.

This reservoir, which relies on the simplicity of common sense as well as the latest technology, will be entirely underground, using existing ground-water basins to store up to 300,000 acre-feet of drinking water. That’s enough to supply 600,000 families for a year.

A series of 30 wells will serve the dual purpose of injecting water into the basin when there is an abundance and pumping it out when water is scarce. About 30 miles of pipeline will be laid to connect the wells to Calleguas Municipal Water District lines.

“You want the ability to put water into the ground when you have it and to produce water to use when you need it,” said Don Kendall, general manager of the district. Calleguas supplies water to Thousand Oaks, Simi Valley, Moorpark, Camarillo and Oxnard.

The district now relies on water pumped through a single pipeline from the Metropolitan Water District, making the region vulnerable to cuts in supplies during earthquakes and droughts.

Kendall signed the agreement in Los Angeles on Tuesday with representatives of Metropolitan, which provides water to 15 million people in Southern California.

“Metropolitan has never entered an agreement like this before,” Kendall said. “It opens a new era of partnership with member agencies to share resources.”

Representatives of cities in the service area praised the agreement.

“The project is vitally needed for all of Ventura County,” said Don Nelson, Thousand Oaks’ public works director. “This will guarantee an independent, reliable and more sustainable water supply.”

Michael Kleinbrodt, deputy director of public works for Simi Valley, said that depending on a flow of water from outside the region is not always a good position to be in.

“We found that out during the earthquake and the drought,” he said. “This helps us drought-proof the area.”

But opponents of the plan have contended that storing that much water in the county’s east end would only induce more growth.

Attorney Glen M. Reiser, who represented Las Posas Basin landowners in a suit to block pilot testing of the project, contended that the large capacity of the reservoir could provide enough water for the county’s population to triple. The suit has since been settled.

Members of Save Open Space, a conservation group, also objected to the possible growth-encouraging aspects of the project.

Kendall said Calleguas does have plans to accommodate future growth. But the project itself is not the impetus for growth, he said.

“We ‘re just trying to take care of the people who are here,” he said. “We’re very vulnerable to interruptions. Until we get about 100,000 acre-feet of water under our feet, we’ll continue to be.”

The North Las Posas Basin Aquifer Storage and Recovery Project has a simple premise based on storing water during wet years to use it during dry years. Metropolitan, which supplies Calleguas, receives much of its water from Northern California.

During the drought years of the late ‘80s and early ‘90s, Metropolitan cut supplies to its member agencies by as much as 50%. In addition, during the Northridge earthquake, the lines between Metropolitan and Calleguas were damaged, leaving Calleguas without its only source of water for a week.

At that time, the district relied on water it had stored in Bard Reservoir near Thousand Oaks, a tiny lake with a 10,000 acre-foot capacity. With 500,000 customers, the district could use that much water during a single summer month.

An acre-foot is enough to supply two families for one year.

During the first phase of the project, which should begin in the next few months, the district will build five wells. Each well will serve as the point where the water is injected into the basin during the wet years, as well as the point from which the water is pumped when needed.

The district will also build pipelines from the North Las Posas Basin to connect to existing Calleguas lines. The first phase is expected to be operational by fall 1996.

The plan also calls for a hydro-generating station to be built in Moorpark near the intersection of Spring Road and New Los Angeles Avenue. In addition, each well will produce a small amount of electricity.

As water flows by gravity from Calleguas to the wells, a small turbine at the well head will spin, creating a small amount of electricity.

“It’s state of the art,” said Eric Burgh, planner for the Calleguas district.