As the dust settled after one of the most challenging harvests in recent memory, North Coast grape growers assessed the damage, and now many are considering beefing up a basic protection: crop insurance.

In Sonoma County, overall grape yields were down an estimated 20 percent below the average of about 200,000 tons, a low that hasn't been reached in more than a decade.

Those who insured their crop received some measure of financial relief, but the payouts varied widely depending on the type of coverage.

"We had a lot of people calling in notices of damage," said Chris Maloney, an insurance broker for Chris Maloney Crop Insurance Services in Petaluma, one of the largest crop insurance underwriters in the state. "We could not transmit the notice of damage fast enough before another call came in."

One of the major problems, especially in white grapes, was a rot that developed in the clusters after fall rains, known as botrytis.

"The botrytis was really exploding ... and for it to go so quick, it caused a lot of damage in a short amount of time," Maloney said.

Yields were low across the board, especially for sauvignon blanc, due largely to the unseasonable rains during bloom that interrupted pollination causing an effect called "shatter," which resulted in fewer grapes on each cluster.

"I'm pretty confident that the claims will be up significantly this year," said Nick Frey, president of the Sonoma County Winegrape Commission. "I think anybody who's got sauvignon blanc probably has a claim."

The official tally of the loss will not be available for a few months. But some growers were reporting losses of 30 percent or more, prompting Lisa Correia, assistant agricultural commissioner for Sonoma County, to begin examining whether the county could be declared a federal disaster area and become eligible for assistance.

To qualify, the county's grape crop would have to be 30 percent smaller than normal.

"It's typically pretty difficult to reach that threshold, but this year we thought there was enough indication that we could start a survey and go from there," Correia said.

About 60 percent of Sonoma County's 60,000 acres of wine grapes have some level of insurance, according to the U.S. Department of Agriculture.

Many of those vineyards are covered only for "catastrophic" losses, which is a relatively low-cost option that kicks in if a grower loses more than 50 percent of the vineyard's average yield. Even then, the payout is only about 55 percent of the average price the grower would have gotten if the grapes matured and were sold. About half of Sonoma County's insured vineyards are covered at the catastrophic level.

"It's a very basic level of insurance, and only in an extreme catastrophe does the grower get paid," said Jim Otto, senior risk management specialist in the Risk Management Agency, a division of the U.S. Department of Agriculture. "In a lot of insurance, you get what you pay for. If you take the higher levels, you are paying a higher premium per acre."

Already, $3.6 million in claims have been paid out for the 2011 harvest, and insurance agents estimate they are at least halfway through the process of paying the claims.

The vast majority of insurance payments have gone to growers who purchased a higher level of coverage: only $22,459 was paid out in catastrophic claims, Otto said. Last year, only 1 percent of the $4.9 million paid went toward catastrophic claims.

John Balletto, president of Balletto Vineyards & Winery in Santa Rosa, had insured his vineyards at the catastrophic level. His chardonnay crop was down about 40 percent, a painful loss, but not enough to warrant a claim. His syrah crop was down about 60 percent, so he recouped a small sum.

"It's not very much right now," Balletto said. "We're actually looking at increasing our coverage to 80 or 85 percent now, because we've had two rough weather years in a row. I think this past year's weather patterns took everyone by surprise."

Sarah McClelland Kunde, owner of Saralee's Vineyard in Santa Rosa, is having a similar change of heart after losing 95 percent of her gew?rztraminer crop in one of her vineyards.

"I usually buy at the catastrophic level, because I'm always an optimist that it is going to be a good crop," Kunde said. "We're all looking at how much to buy for next year, and to buy more."

Price is one reason catastrophic coverage is so popular. Coverage costs a flat fee of $300 per varietal, regardless of the number of acres in the grower's vineyards.

Purchasing higher levels of coverage can get expensive quickly. For example, it would cost a grower $1,100 to insure a 10-acre chardonnay vineyard at the 75 percent level.

But the difference in payouts can be striking.

A grower with catastrophic coverage on that chardonnay vineyard would be paid just $1,950 if they lost all but two tons of a 40-ton crop valued for insurance purposes at about $71,000, but a grower covered at 75 percent would receive nearly $50,000.

"It seems like increasingly, more and more people are opting for the higher-priced elections and more coverage," Maloney said. "It's just, I think, a direct reflection of what's happening with the weather. It's so unpredictable."

Insurance adjustors also have been busier this year. Frank Anderson, retired co-principal of El Molino High School in Forestville who also co-owns a vineyard, became a part-time insurance claims adjustor with Rain and Hail Insurance Services last year. But during this harvest, it was more of a full-time job than he expected.

"They loaded me up until I finally cried uncle," Anderson said. "From what I can see, this is certainly a bigger year than last. And I know last year, it was big."