If the debilitating drought continues, farmers and ranchers with rights to California's creeks, rivers and lakes may be ordered to stop drawing the water that is vital to agricultural operations.
That is the message Gov. Jerry Brown sent last week in his emergency drought declaration that, among other things, put water rights holders on notice that they may be directed to cease taking surface water.
The order is a further blow to grape growers along the Russian River basin who already fear that one of the worst droughts on record will ravage their crops.
The State Water Resources Control Board is evaluating the level of waterways around the state, said John O'Hagan, the board's enforcement manager. If flows get too low, officials will tell water rights holders to turn off the tap.
"This is a fluid process," O'Hagan said. "It is happening throughout the state. We will make a determination (on curtailment) within a short time."
The curtailment will affect newer water right holders first and could continue until those with more senior water rights are told to stop taking water from rivers and creeks, he said.
The Sonoma County Water Agency, which provides Russian River water to 600,000 residents and is a senior water rights holder in the Russian River watershed, is assessing how the governor's order could affect its operations, spokesman Brad Sherwood said.
The agency has been preparing for drought since last year, the driest on record, Sherwood said.
"We fully support the governor's declaration," he said. "Our region has been proactive. We want to lead the charge on this issue."
The state water board curtailed water rights during epic droughts of 1976-77 and 1987-88, O'Hagan said. Non-compliance with the order would be met with a fine of up to $500 per day.
Grape growers, who have had only about 2 inches of rain since July 1 -#8212; 13 percent of normal -#8212; are worried about losing an important source of water for frost protection and irrigation.
Jim Murphy, who owns 170 acres of vineyards along the Russian River near Geyserville, said the state shouldn't touch people's water rights.
"It's not the right move," he said. "The water rights come with the land and they need to stay with the land. We want to protect our water rights."
Vineyard managers already are considering extreme measures to protect the vines including trucking in water and reducing the fruit from the upcoming crop.
Duff Bevill, who manages 1,000 acres in the Alexander Valley, Dry Creek and Russian River Valley, said if the drought persists, a whole year's harvest could be lost.
"The next step is to reduce the crop," he said. "If it gets worse, the next step is to forget about the crop; do what you can to save the vineyard and look to next year. You can't help but plan for the worst."
Sonoma County Winegrowers, an industry group, is convening a meeting with growers and water managers Feb. 4 to talk about the drought emergency, said president Karissa Kruse. She said there has been an increase in growers buying crop insurance and that the 2014 crop could produce less wine than in average years.
The lack of rain combined with unseasonably balmy weather could cause an early bud break, she said. That could expose the vine at a delicate stage to greater risk of frost, which is harder to protect against when water supplies are limited.