Sonoma County supervisors voted unanimously Tuesday to scale back controversial rules designed to protect endangered fish and regulate how grape growers use water from the Russian River for frost protection.

The board eliminated rules that would have required vineyard and orchard operators to monitor and report their water diversions from the river, its tributaries and nearby groundwater.

A county program that simply registers growers who use Russian River water for frost protection will continue. Going forward, it will only require registration for new growers, or operations that have been modified or changed hands. The registration fee is $64.

The shift was spurred by state regulations approved last year that impose many of the same requirements, including monitoring and reporting, with stronger enforcement authority to back them up.

The state rules are tied up in court after a coalition of grape growers sued and a judge postponed their enforcement. Many grape growers in Sonoma County and Mendocino County are complying with the rules in the meantime.

Sonoma County's program drew heavy fire from some growers early last year when it came before the Board of Supervisors.

Critics took issue with a reporting requirement that would have identified how much water individual growers were taking from the river system for frost measures.

John Dyson, the high-powered owner of Williams Selyem winery in Healdsburg, compared such measures to a "witch hunt."

Under pressure, the board postponed implementation of the monitoring and reporting rules until this year. That step is no longer warranted with the unveiling of state rules, county officials said Tuesday.

Wine industry representatives agreed. "This is the authority of the state. It's their job. It's what they do. It's why they exist," said Bob Anderson, executive director of United Wine Growers for Sonoma County.

Environmentalists who questioned the strength of the county program last year urged supervisors to revisit stream monitoring and reporting in the future.

They also lobbied for an expanded registration program. While the county requires growers to detail the type of water diversion they use, their source of water and the acreage they protect from frost, it does not require a proof of state water rights, said David Keller, Bay Area director for the Friends of the Eel River.

"Helping to find out whether or not your applicants have a legal right to use this water is important," Keller said.

County Agricultural Commissioner Tony Linegar confirmed the county does not ask for proof of water rights. But state officials have access to county registration records and have reviewed those records, according to Linegar and David Hurst, chief deputy county counsel.

Linegar told the board that adding a check for water rights "would be a discussion we could have."