Last month, Simi Valley got another step closer to $1.5 million in state-issued Proposition 50 grant money necessary to help offset the cost of building the $4 million Tapo Canyon Water Treatment Plant.

The yet-to-be-constructed plant is part of the city's Capital Improvement Program approved after the 1994 Northridge earthquake and is expected to yield 1,350 acre-feet, or around 450 million gallons, of drinking water per year. That amounts to about 2 percent of total water sales in the city. An acre-foot is estimated to be enough to supply two families for a year.

According to Joe Deakin, assistant director of public works, the treatment plant will be used to demineralize and soften groundwater from the Tapo Canyon Basin, providing a local source of drinking water and saving the city money it would otherwise have to pay to the Calleguas Municipal Water District, where Simi gets 100 percent of its drinking water.

"We figure the payback period for the plant, considering the reduced cost of water supply, should be less than eight years," Deakin said.

California voters passed Proposition 50 in 2002 to fund a variety of water projects around the state. Part of the focus of that initiative, Deakin said, was to encourage cities and counties to do more to find local sources of water, thereby reducing the demand on the Colorado River and Sacramento Delta.

"The idea was to become more selfreliant by developing local resources," Deakin said.

In order to receive the slated $1.5 million from the state Water Resource Control Board, the city, with help from the public, must devise a groundwater management plan for the basin. But that's not the only rationale for creating the plan, Deakin said.

"It is required by the grant, but it's also good practice when dealing with a basin so we don't diminish its long-term sustainability," he said, adding "We want to make sure water is in there for the long run."