Sonoma County flirts with drought as reservoirs recede in water-poor winter

Closer to home, Cal Fire Division Chief Ben Nicholls said he’s worried by a forecast for dry offshore winds, blowing from east to west and gusting from 20 to 45 mph on Sunday through Tuesday, compounded by sunny days in the low 70s Sunday and Monday.

The warm, dry spell will create “elevated fire conditions,” he said, calling it added evidence that California’s wildfire season “is truly year-round.”

While global warming, among other factors, is cited for California’s increasingly frequent and fearsome wildfires, meteorologists point to La Niña — a phenomenon characterized by unusually cold water temperatures in the tropical Pacific Ocean — as the force behind the arid winter.

“It’s what we would expect from a moderate La Niña system,” said Max Gawryla, a meteorologist with AccuWeather, a private company that provides forecasts for The Press Democrat’s weather page.

Storm fronts from the Gulf of Alaska are being shunted to the north by a ridge of high pressure shielding the Bay Area and diverting the rain to the Pacific Northwest and the Rocky Mountains, he said.

“Let’s call it the Great Bay Area Wall,” said Brian Garcia of the National Weather Service office in Monterey, noting that rain is falling aplenty from Humboldt County northward.

Sonoma County’s coastal mountains also form a barrier that is “eating up the rain,” reducing precipitation from about 50% of average to 30%, he said.

The shortfall is affecting agriculture, including the county’s two largest commodities — wine and milk — and even curbing wastewater flow to Santa Rosa’s treatment plant.

Joe Pozzi, a Valley Ford cattle and sheep rancher, said farm ponds are falling and natural springs, like the ones he relies on for water, are drying up. The biggest problem, however, is stunted growth of grass in livestock pastures.

Without rain, ranchers are forced to deplete their stocks of dry hay, buy more feed or — as a last resort — downsize their herd.

“We’re not there yet,” said Pozzi, who’s been ranching since 1984.

“No matter how much dry hay you put out, the animals don’t do as well as they would on grass,” he said.

“It’s starting to get a little scary,” said Doug Beretta, who runs the Santa Rosa-area dairy founded by his grandfather in 1948.

If the dry spell continues, Beretta said he might have to start buying hay, and worries about whether the supply from California, Oregon and Nevada will be sufficient in a county with 56 licensed cow dairies.

There are 47 certified organic dairies, including Beretta’s, that face an added concern over federal regulations mandating that every animal over six months old must spend at least 120 days in pastures receiving 30% of their feed.

Dairies that can’t meet the standard might have to shrink their herd or apply for a variance from the rule.

Some dairies are trucking in water to sustain their cows, which can drink a third of their body weight — 40 to 50 gallons of water — a day.

Beretta also is one of the 63 farm operators who obtain recycled wastewater from Santa Rosa’s treatment plant on Llano Road. That water can legally be consumed by animals not producing milk.

But the rain-stingy season has also reduced water flowing into the treatment plant and the amount of recycled water stored in ponds at the facility, said Jennifer Burke, director of Santa Rosa Water.

There are usually 600 million gallons in storage this time of year, but there are now only 400 million gallons and the gap is likely to grow as storage capacity under normal weather conditions increases into spring, she said.

Without sufficient rainfall there may be “very little recycled water available” this year for agricultural users, Burke said.

Santa Rosa pipes 4.6 billion gallons of treated wastewater to geothermal power plants at The Geysers and stores the rest.

Grapevines are dormant during winter, immune to the dry conditions for now, said John Bidia, director of vineyards operations at Korbel Winery.

But the lack of rain is failing to replenish soil moisture and could impact the grape growing season, he said.

When the vines start waking up in March they may need water for frost protection, said Bidia, who is in his 41st year with Korbel.

Two of Korbel’s seven vineyards store water in ponds; one is about 30% full and the other essentially empty with the water level below the outlet pipe.

Sonoma County’s dairy industry dates back to the 19th century and milk was the top commodity until it was surpassed by grapes in 1987.

The county’s 2018 crop report, the latest one published, valued agriculture at $1.1 billion with wine grapes at nearly $778 million and milk at $141 million.

It’s unclear whether the county is entering a drought, since there are two weeks remaining in January, which averages 7.05 inches of rain, along with February (6.63 inches) and March (4.98 inches).

“That’s the question everybody is asking,” said Davis, the water agency head.

The U.S. Drought Monitor placed more than 95% of California in one of four stages of drought last week. Nearly all of Sonoma County was in severe drought, while Napa and Lake counties were a level higher in extreme drought and Mendocino County was about evenly divided between the two levels.

A year ago, none of the state was in a drought condition.

Ultimately, it is up to the Gov. Gavin Newsom and the Department of Water Resources to declare a drought, Davis said.

But there could be a break in the dry spell the weekend of Jan. 23 and 24, when AccuWeather, which does long-range forecasting, said the North Bay could get a half-inch to an inch of rain, followed by another 2 to 3 inches in the last week of the month.

“That would be huge. This could change overnight,” Pozzi said.

“We could make up a lot,” Beretta said

La Niña should fade in spring, offering the prospect of relief, meteorologist Garcia said.

But as much as the region needs rain, it could prove harmful if a downpour triggered debris flows over the region’s massive wildfire burn scars, he said.

“What we need is Goldilocks rain: not too little, not too much,” Garcia said.

There is also the possibility of a “March miracle” delivering enough precipitation to terminate a drought in one prolonged storm, but also bringing the threat of flooding.

In early March 2016, near what would be the end of California’s worst drought on record, a heavy storm, known as an atmospheric river, pumped both Lake Sonoma and Lake Mendocino up to more than 100% of capacity, leaving both the fullest they had been at that time of the year since 2012. It also stopped in time to avert flooding.

March miracles can be the stuff of dreams, said Brad Sherwood, a Sonoma Water spokesman. “They happen once in a while and when they do we dance with joy.”

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.