SATICOY : Old Gravel Pit Will Become Reservoir

A Santa Paula-based water district is transforming an abandoned gravel mining pit into a reservoir, creating water storage that will help stem the flow of seawater into fresh underground water basins.

The United Water Conservation District, which monitors pumping and replenishes underground water supplies for much of the county, plans to have the new reservoir in operation by mid-February, said Frederick J. Gientke, United’s general manager.

The conversion of what once was CalMat Co.’s Noble Pit will help restore water levels in the upper Oxnard Aquifer for the first five years. After that, its water supply will be used to reduce pumping from the valuable Fox Canyon Aquifer beneath the Oxnard Plain.

Fox Canyon, the largest underground water basin in the county, has been overdrawn for the last 50 years by growers and cities that have pumped more out each year than rainwater can replenish. That has allowed seawater to gradually penetrate the aquifer.

The same is true for the shallower upper Oxnard Aquifer, but United has already launched projects to help replenish its supply.

“For the first time, we’re able to directly attack the overdraft in the Fox Canyon,” Gientke said. “With the Freeman Diversion and the Saticoy and El Rio spreading grounds, only about 15% of the water went into the lower aquifer.”

United purchased the 144-acre pit from the Saticoy-based CalMat Co. for $2 million and will spend another $2.5 million grading and preparing the pit and building pipelines.

The reservoir, called the Fox Canyon Seawater Intrusion Abatement Program, will store up to 3,000 acre-feet of water per year.

The Freeman Dam on the Santa Clara River at Saticoy now diverts water during heavy flows after storms. That water is funneled into nearby settling ponds, which allow water to sink down into the ground and percolate into the aquifers below.

Excess water that the settling ponds cannot handle will be shunted off to the Noble Pit. For the first several years, the water will be allowed to percolate into the shallow water basins.

But once the pond seals itself off with silt in four or five years, the district will build a small pumping plant and ship the water via existing pipeline to growers on the Oxnard Plain. In turn, those growers will decrease the amount of water they pump from the Fox Canyon Aquifer.

The water will cost about $110 an acre-foot, which is enough water to supply two families for one year. Once the project is paid off in 20 years, the will cost drop to $3 per acre-foot, said United board President Dan Pinkerton.

“In that time, over 60,000 acre-feet of water will have been conserved,” he said.