Dam Project to Stop Seepage of Seawater

A $28.5-million upgraded water diversion system under construction near Saticoy will save Ventura County an additional 4.2 billion gallons of water each year, United Water Conservation District officials say.

A concrete-and-steel dam will replace an earthen structure that now diverts nearly 14 billion gallons of Santa Clara River water each year for county use.

The structure, scheduled for completion in March, will stretch 1,740 feet across the river basin and rise 25 feet from the riverbed. A specially constructed fish ladder will allow rainbow trout to pass from one side of the structure to the other.

Water diverted from the Santa Clara River basin is pumped into shallow dirt ponds covering 133 acres near Saticoy. Once in the ponds, the water naturally percolates through the soil and replenishes the ground-water supply.

In addition to the one near Saticoy, the United Water Conservation District operates diversion systems in Piru and El Rio along the Santa Clara River.

The improved Saticoy area diversion system will prevent the further intrusion of seawater into the Oxnard plain, according to Fred Gientke, United Water Conservation District general manager.

More fresh water is being pumped out of the Oxnard plain than is pumped in, Gientke said. As a result, underground fresh-water levels have been brought down below sea level, and about 25 square miles of the Oxnard plain have been contaminated by the intrusion of seawater.

Farmers use 75% of the water pumped out of the Oxnard plain, Gientke said. The remaining 25% is used by the cities of Oxnard, Ventura, Camarillo and Port Hueneme.

Farmers and growers are charged $13.50 per acre-foot of water, but local municipalities pay $40.50 per acre-foot. One acre-foot of water, or 325,000 gallons, is about the amount used by a family of four in one year.

Although the new dam will be capable of diverting up to 56,000 acre-feet of water per year from the Santa Clara River, most of the river water will flow into the ocean. Each year, the river washes about 110,000 acre-feet of fresh water, or 35.7 billion gallons, into the Pacific Ocean.