62 Days Until 17-Acre Emergency Reservoir Tops Off

More than 240 million gallons of water are flowing into a 17.8-acre reservoir that will keep San Juan Capistrano residents from seeing their faucets go dry in an emergency.

Water began streaming July 18 into the $53.7-million Upper Chiquita Reservoir in Rancho Santa Margarita. It is expected to be completely filled up by September, providing a "buffer" from disruptions in water imports and a "hedge" against natural disasters.

San Juan residents will pay $45,045 for the city's share in filling the storage unit, considered to be the first large-scale emergency potable water reservoir built in Orange County in decades. The water was purchased from Metropolitan Water District, a wholesale water supplier that delivers to most of Orange County.

Located on the western slope of Chiquita Canyon, just north of Oso Parkway, the reservoir took two years to build, and required excavation of 1.4 million cubic yards of dirt from the canyon floor.

San Juan's cost to the fill the reservoir is in addition to its $5.1-million share of the cost of construction, which ran up an additional $78,467 than initially anticipated in June 2009, when the city signed onto the project with four other local water agencies.

At its meeting Tuesday morning, San Juan's Utilities Commission agreed to the additional costs. For $5.1 million, San Juan's share of the reservoir is 24.8 million gallons.

"The final cost of $5,103,552 works out to $0.206 per gallon, and compares favorably with the cost of constructing reservoir storage within the city," San Juan's assistant utilities director, West Curry, wrote in a report to the city's Utilities Commission.

The city operates its own Groundwater Recovery Plant, fed by local wells and imported drinking water from Metropolitan Water District of Southern California.

MWD sends the water—tapped from state-owned reservoirs and aqueducts north of Pyramid Lake, and from the Colorado River—to the Diemer Filtration Plant in Yorba Linda, where it's purified and tested to meet federal standards. It's then piped to the plant next to City Hall on Paseo Adelanto.

As the water traverses California, it's subject to earthquakes, fires and other natural disasters that could destroy the pipes through which it flows and leave local residents without drinking water. The Chiquita Reservoir could also supply residents during planned outages of the Diemer Filtration Plant, which is shut down one week per year for routine maintenance.

"The partners of the [Upper Chiquita] reservoir are entitled to the water when needed," said Michele Miller, a spokeswoman for one of the reservoir's partnering agencies, the Rancho Santa Margarita Water District.