In drought-prone California, it turns out that one of the most reliable sources of water is the stuff that's already been used.

The importance of recycled water — municipal wastewater treated and then reused for irrigation, landscaping and even to replenish groundwater — has grown as the state struggles with a drought year and limits on new sources for water.

On Wednesday, local members of the Association of Water Agencies of Ventura County heard about ways to tap into this source from experts in the field of water reuse.

Although some people, as well as some water agencies, are uneasy about the use of recycled water, Steve Bachman, groundwater resources manager for United Water Conservation District, said soon water reuse will be required of all water agencies.

"One of the things that's being considered (by the state) is that if you're not using it, it would be considered a waste of water," Bachman said at the workshop in Oxnard.

The workshop was the third in a series of four put on by the agency for its "Drought Watch 2008."

It included presentations from the chairman of the California Building Industry Association, from a water agency that delivers recycled water for industrial uses, and a consulting firm on the nuts and bolts of implementing a water-recycling program.

Steve LaMar, chairman of the California Building Industry Association, said his group believes that it's in the industry's interest to push for more aggressive conservation, adding that he believes water is undervalued.

"In the paper yesterday, I saw that in Stockton, they're paying one-tenth of a cent for a gallon of water, and that just doesn't seem right, especially when you consider we're paying $4 for a gallon of gas," LaMar said.

Ventura County is not a leader in the use of recycled water, but statewide, there has been a push to increase its use.

State officials want California to use 1 million acre-feet of recycled water a year by 2010. One-acre foot equals 325,851 gallons.

Gov. Arnold Schwarzenegger is also pushing to require that water agencies reduce water use by 20 percent — through efficiency or reuse — by 2020.

Unlike places such as Orange County, which recently began using treated sewage to augment drinking water supplies, or Los Angeles County, where recycled water is commonly used for irrigation, water reuse is still in its infancy in Ventura County.

The Camrosa Water District, which has about 30,000 customers in Camarillo and the Santa Rosa Valley, recently began reusing water for irrigation at CSU Channel Islands, on farm fields and to water the golf course at Leisure Village.

The city of Oxnard is also embarking on a water-recycling program. Estimated to cost about $100 million, the program daily will produce about 6 million gallons of recycled water that will be used to replenish groundwater, halt seawater intrusion and irrigate farm fields.