SANTA ROSA -- The Sonoma County Board of Supervisors has postponed until Feb. 8 a hearing on final details for the recently adopted Sonoma County Vineyard and Orchard Frost Protection Ordinance before growers are required to start registering their water-based frost-fighting systems on March 1.

The board was set to consider on Tuesday proposed fees growers would pay to cover the ordinance's monitoring and reporting provisions, finalize a three-year ordinance implementation contract and clear up lingering details, according to the agenda posted today.

Proposed fees for the program are $300 for growers to register and $12.50 per acre of land guarded against frost.

The county Assessor's Office found that nearly 19,000 acres of vines in the county have frost-protection systems. Yet only 16,000 acres are protected with overhead sprinklers, which can consume as much as 50 gallons per minute per acre on frosty nights. The number of sprinkler-protected acres that draw water from the Russian River watershed is estimated to be 11,000, when use of recycled water and other watersheds are considered, according to Lex McCorvey, executive director of the Sonoma County Farm Bureau.

"One of the issues some growers will have is if they have to pay the fee if they don't use Russian River water," he said.

Adopted Dec. 14, the ordinance requires growers to register with the county Agricultural Commissioner’s Office how they use water for frost, including equipment used as well as source and location of the water diversions. Starting next year through 2013, a network of 70 to 100 gauges would be installed on 22 key fish habitat creeks to monitor stream flow.

The county would contract with a grower nonprofit to administer the program. An independent science review panel led by Matt Kondolf of U.C. Berkeley would analyze the stream data and send it to resource regulators for comment before forwarding the information to the state each December.

The goal of the ordinance is to prevent leaving protected fish, particularly endangered Coho salmon and threatened Chinook salmon, without enough water during frosty nights. The National Marine Fisheries Services petitioned the State Water Resources Control Board in spring 2008 to take action on Russian River Basin frost-water use following a few reports of fish found dead during a historic monthlong stretch of frosty nights.

The Sonoma County Board of Supervisors is set to consider the fee proposal, management contract with Russian River Watershed Coalition and final revisions to the ordinance on Feb. 8 at 2:10 p.m.