Gov. Jerry Brown's declaration Friday of a drought emergency in California does not immediately trigger new restrictions on water use on the North Coast, where officials already have begun asking people to voluntarily cut back their use.

Brown, speaking in San Francisco Friday, said California is in perhaps its worst drought since record-keeping began a century ago.

His proclamation states that drought and water shortage are creating "conditions of extreme peril to the safety of persons and property" in the state. The governor asked Californians to reduce their water usage voluntarily by 20 percent.

"We are in an unprecedented and very serious situation," Brown said. "It's important to awaken all Californians to the serious matter of drought and the lack of rain."

State lawmakers had been urging Brown to issue the declaration, which allows California to request a broad emergency declaration from President Barack Obama. That could expedite some water transfers within the system linking the Central Valley and southern California, provide financial assistance and suspend some state and federal regulations.

The drought emergency follows a third straight dry year in California and an almost bone-dry January for most of the state. The Sierra Nevada snowpack measured just 17 percent of normal this week, threatening reservoir supplies across the state.

The North Coast is different from much of the state in that its water comes from moisture that sweeps across the Pacific Ocean in clouds and falls nearby on mountains in California's coast range.

For much of Sonoma and Mendocino counties, the moisture is collected in two reservoirs near Ukiah and Healdsburg and sent to Russian River pumps near Forestville. From there, water is sent south through underground pipelines, stored in massive tanks and then piped under city streets to 600,000 residents and businesses in Santa Rosa, Windsor, Rohnert Park, Cotati, Petaluma and Sonoma and water districts in Sonoma Valley and Marin County.

Lake Sonoma northwest of Healdsburg held 165,000 acre feet of water, or roughly 67 percent of its water-supply capacity, as of Friday. The reservoir would have to drop to 100,000 acre feet to trigger mandatory conservation, said Water Agency spokesman Brad Sherwood.

"Lake Sonoma is really our saving grace right now," Sherwood said. "Without that water supply, without a doubt we'd be facing Draconian mandatory water conservation regulations right now."

Drought conditions already are having a severe impact on the North Coast's agricultural industry.

West county rancher Joe Pozzi said many ranchers are running out of supplemental hay to feed their animals. He said normally this time of year, winter rains green up the pastures and provide that food.

"This is by far the worst I've seen in all my years," Pozzi said.

He said the next 30 days will be critical for ranchers, as without significant rain, they could burn through their remaining supplies of hay. Pozzi said in that event, ranchers could benefit from state or federal assistance.

"The best thing we could get is rain. But it doesn't look like that's going to happen," Pozzi said.

Ranchers and farmers already are eligible for low-interest loans to help cover losses related to forage crop loss, said Tony Linegar, Sonoma County's agricultural commissioner. The loans are administered by the Farm Services Agency of the United States Department of Agriculture.

Linegar said the loans were made available starting in August after the U.S. Drought Monitor listed Sonoma County as experiencing severe water shortage. Linegar said the county is now working to extend that designation, which would extend the loan period.

He said the county also is launching a survey next week to determine the extent of forage crop loss.

Linegar called it a "real dire situation," with farmers and ranchers having to pay to truck hay in from as far as Oregon and Washington.

He said some grape growers also may not be able to protect their crops from frost damage this year by pulling water from tributaries or rivers, as those waterways are dry or below acceptable levels.

Early bud break on the vines also is a concern, as it lengthens the amount of time fruit is exposed to frost.

"More growers are getting crop insurance this year because they see the writing on the wall," Linegar said.

Farther north, communities are bracing for a dire situation as Lake Mendocino threatens to drop below the pumping intake.

Without rainfall, the lake could disappear in 230 to 670 days, depending on water flows into and out of the lake, evaporation rates and amount of lake sedimentation, according to the U.S. Army Corps of Engineers.

The Water Agency and the nine municipal and regional water systems that buy its water launched their first-ever wintertime conservation campaign last week with the theme, "The Drought is On; Turn the Water Off."

David Guhin, utilities director for the city of Santa Rosa, said Brown's emergency declaration "gives validity to the dire situation the state is in."

"This is a serious issue and we need to rethink how we are using our water at this point. It's good to see the governor make this step," Guhin said.

Santa Rosa ended 2013 with just 8.71 inches of rain, according to Press Democrat records. The normal rainfall is 32.22 inches. According to Water Agency data, last year was the driest in 119 years of record keeping, well below the severe drought years of 1976 and 1932.

The city is voluntarily asking residents to use nozzles on hoses when watering, not use water to clean hard surfaces and to receive water at restaurants only on request. The first state of mandatory water use restrictions would include all of those restrictions, and limit irrigation to between the hours of 8 p.m. and 6 a.m.

The city of Willits has adopted the most serious water restrictions so far, mandating that households be limited to 150 gallons per day. The city's water reservoirs contain an estimated three month water supply.

(You can reach Staff Writer Derek Moore at 521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.)