SAN CLEMENTE : Use of Pendleton Water Table Studied

Negotiations have begun to allow San Clemente to tap a vast water table beneath Camp Pendleton, a reservoir that could increase the city’s water supply at least sevenfold.

Last week, the Tri-Cities Water District board of directors voted to explore the possibility of using the 300-million-gallon water table as an emergency storage area. The reservoir would serve a major portion of the South County, including San Clemente, Capistrano Beach, parts of Dana Point and the San Onofre Nuclear Power Station.

Authorities plan to begin a $270,000 project to test the so-called San Mateo water basin for impurities, said Ray Woodside, district general manager.

“It would be a big security blanket,” Woodside said. “This would be a major step if we could generate this reserve.”

The Tri-Cities Water District has reached agreements with the Metropolitan Water District and Capistrano Beach County Water District and a tentative agreement with the city of San Clemente about sharing costs of tests.

If the tests find no major contaminants, that consortium will continue negotiating with the U.S. Marines for a million-dollar project to drill wells on Camp Pendleton and install water lines between the camp and the South County, Woodside said. Water would be purchased from the Metropolitan Water District, as it is now, and stored in the basin.

“If feasible, we could store water in the San Mateo basin to be used during peak periods of water use,” he said, “or emergencies like a broken water line.”

Woodside said finding a site for an above-ground reservoir is difficult.

“Water storage is very expensive,” he said. “The cost of land is high, and then you have to pay for building a structure to hold the water.” Underground reservoirs “don’t have that problem.”

Last year, the water level in the district’s 48-million-gallon reservoir sank to an all-time low of 17 million gallons on Aug. 18.

Through a series of tough water-saving measures enacted by San Clemente, the district’s largest customer, the reservoir levels have remained higher than last year.

On Monday, the reservoir held 42 million gallons, Woodside said.

Greg Morehead, water supervisor for San Clemente, said the underground reservoir would provide the city “a substantial supply of new water. It would make things a lot more comfortable” during drought conditions.

Builders are not permitted to use water for grading until Sept. 15; residential lawn watering is restricted during the day.

Warnings have been issued but nobody has been cited for breaking the water law, Morehead said.