A Mendocino County grape grower has been fined $33,800 by state water regulators for an alleged illegal diversion of water from a Russian River tributary.

Since 1999, Hopland-based Milovina Vineyards has been diverting water from an unnamed creek near its property to fill an unauthorized 1.4-acre reservoir used for irrigation and frost protection on 41 acres of grapes, regulators from the State Water Resources Control Board said.

The fine recommended by water board staff covered only a three-year period of the alleged violation. The maximum penalty over 14 years would have been almost $2.6 million, according to the state, based on the $500-per-day fine the state can impose in such cases.

The penalty was announced by the water board on Wednesday along with a cease and desist order it made on the unsanctioned diversion earlier this month.

Representatives of Milovina Vineyards, including co-owner Jim Milovina, could not be reached for comment Thursday.

The state enforcement is part of a larger crackdown on unauthorized stream diversions in Wine Country and along the North Coast. Federal officials say diversions for agriculture are a primary cause of mass strandings and fish kills for federally protected salmon and steelhead runs.

Local growers and Mendocino County water officials have disputed those claims and led a successful court challenge to state rules that would have imposed tighter restrictions on Russian River diversions for frost protection.

The general crackdown on unauthorized water diversions began in April 2010, with notifications to property owners that all unreported unpermitted uses dating from 2009 forward would be subject to monetary penalties.

Data on the total number of illegal diversions detected by the state as part of the crackdown and the amount of fines handed out were not available Thursday.

According to the state, Milovina Vineyards filed paperwork that identified its unauthorized reservoir in June 2010, after the state notice. Late last year, the grower filed an application for a water right connected to the reservoir, state records show.

No evidence was found to link the vineyard's diversion to a fish kill, said Jim Kassel, assistant deputy director overseeing water rights for the state board.

The fine for Milovina Vineyards, at 12350 Hewlitt-Sturtevant Road in Hopland, follows two other water diversion penalties issued this year to local landowners. Andrew Flocchini, a rancher off Lakeville Highway in Petaluma, was assessed a $42,000 fine for an unauthorized steam diversion to a 3.4 acre reservoir used for irrigation and livestock watering.

Bruce, Jim and Russ Henning, owners of Henning Ranch off Lakeville Highway, face an $18,000 penalty for an unpermitted diversion to a 1.9 acre reservoir.

Landowners are allowed to appeal and request a hearing before the state water board to contest fines. The board retains final say on the amount of any penalty, with the ability to adjust it up or down within the limits of state law.

You can reach Staff Writer Brett Wilkison at 521-5295 or brett.wilkison@pressdemocrat.com.