PLAN RELIES ON WELLS FOR WATER : PALMDALE'S PROPOSAL TO INCREASE USAGE WORRIES COUNTY OFFICIALS.

Byline: Bhavna Mistry Daily News Staff Writer

Palmdale Water District is proposing to increase its use of well water substantially over the next 19 years to meet population growth.

The plan has raised concern among officials of other local water agencies, who say overuse could damage or deplete the underground basin that supplies wells for the entire the Antelope Valley.

According to the master plan designed to lead Palmdale Water District into the year 2015, officials expect to increase water sales from about 23,200 acre-feet last year to 45,400 acre-feet in 2015, as the population doubles from about 84,000 to more than 168,000.

At its maximum, the proportion of water drawn from wells, according to the master plan, would be about 40 percent - down from 45 percent today - with the remainder coming from Littlerock Reservoir and the California Aqueduct.

``That is our goal for dry peaking periods,'' said manager Dennis LaMoreaux. ``The majority of the time our surface water usage would be greater than 60 percent.''

An impact report examining the effects the master plan may have on the environment is expected to be made public today and will be on review for 45 days.

``We've introduced our plan, but we are not saying this is what we're going to do,'' said LaMoreaux. ``We are letting people review it and taking comments.''

Los Angeles County officials say they are concerned that increased well use will draw more water from the underground basin than can be replenished naturally by rainfall.

Most local water officials believe that is already happening, although at a lesser rate than when irrigated alfalfa fields covered much of the valley during the 1950s.

``Our concern is that their usage may cause a deterioration to the basin,'' said Dennis Hunter, assistant deputy director for Waterworks and Sewer Maintenance for Los Angeles County. ``We're asking them to do a study of what (effect) their extractions will have on stability. If we all pump irresponsibly, we will deplete the groundwater basin.''

The county-run water district, which supplies much of Lancaster, west Palmdale and other areas in the valley, has a goal to get 80 percent of its supply from the aqueduct, Hunter said.

``Our whole objective is to maximize our surface water and minimize our groundwater usage,'' he said.

The county's present supply is about 60 percent aqueduct water, 40 percent well water, and officials said they are working on plans to minimize well-water usage and replenish the supply.

In a pilot program, county officials are injecting aqueduct water underground, checking the aquifer's retention ability and the effect on water quality.

``If this works, we can save surface water during the wet periods to use during dry periods,'' Hunter said.

Palmdale officials said injecting water underground would not be feasible for their district because the ground is higher than most of the valley. There is no guarantee the injected water would be there when they went to withdraw it later.

``Whenever we can, we'd like to use as much surface water as we can,'' LaMoreaux said. ``But it's going to take a cooperative effort to deal with the basin.''