Supervisors will consider approving a charge of $66.23 per acre-foot of water per year to cover the costs of maintenance and operation of the Salinas River Diversion Facility, a rubber dam soon to be built as part of the Salinas Valley Water Project.

The charges are to be paid by property owners in what is known as “Zone 2B,” an area that covers 12,043 acres stretching from north of Marina to Moss Landing, and from the coast to near Espinosa Lake.

The area is part of the Castroville Seawater Intrusion Project, which uses recycled water to irrigate those acres instead of pumping groundwater.

Construction on the dam is set to begin in April, with the water project operational in 2009. A ground-breaking ceremony for the dam was held Thursday.

Maintenance and operation of the diversion facility are expected to cost $1.26 million for the 2008-09 fiscal year.

Property owners were notified of the new fees in December, the report said, but can force an election if a majority of them protest the charges.

The Salinas Valley Water Project is composed of a rubber dam, pumps and equipment that will cover 5.7 acres of the Salinas River about five miles above where it empties into the Pacific Ocean.

The rubber dam will inflate during the summer to capture Salinas River water that otherwise flows to the Pacific Ocean, with the intent of helping the Salinas Valley’s underground aquifers recharge.

A second component of the project will modify a dam spillway on Lake Nacimiento in south county to better control the flow of water from the reservoir.

Contact Dawn Withers at withers@thecalifornian.com.