After more than five years of unrelenting drought, a series of winter storms has drenched Northern California in recent weeks. That's welcome news for the wine industry, as heavy rain and snow put a dent in the state's water deficit. But no one's cheering too loudly yet. Large parts of the state remain in a drought.
"We are off to an incredible start, basically 15 inches of rain since September and another 3 [inches] expected this week," said Eric Jensen of Booker in Paso Robles, one of the wine regions hit hardest by the drought. "While it hasn't taken us off the severe drought list yet, I am giddy like a kid at Christmas that we have obtained these totals. And we're only halfway through January."
According to U.S. Drought Monitor, a partnership between the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration, as of Jan. 12, more than 40 percent of California, including Napa, Sonoma and Mendocino counties, no longer faces drought conditions.
Conditions have also improved on the central coast and southern California. But regions such as Paso Robles and Santa Barbara remain in severe drought. "From a general perspective, things are greatly improved," said Dr. Michael Anderson, California state climatologist with the Department of Water Resources. But he acknowledges that the report only offers a broad picture of the drought, missing the nuanced water issues in individual regions.
Northern California received the brunt of the storms. Days of heavy rain arrived during the second week of January, replenishing parched reservoirs and basins. Some reservoirs filled so fast that they had to be drained. The storms have also blanketed the Sierra Nevada mountains with snow, pushing statewide snowpack totals to 163 percent of normal levels for this date.
In Sonoma and Napa, rivers and creeks overflowed their banks, flooding low-lying vineyards. But vintners aren't concerned about damage to their vines since the plants are dormant during the winter. "If [the vineyard] is going to be under water, this is the time of year for it to happen," said Steve Dutton of Dutton Ranch in the Russian River Valley.
"This was easily the hardest rain I've seen since the New Year's Eve flood of 2005," said Jeff Ames, owner and winemaker at Rudius in Napa Valley. He estimates his vineyard on Howell Mountain has received 33 inches of rain in the past 30 days. The saturated soils should help replenish groundwater and relieve stress on the vines, which have produced smaller crops in recent years.
But years of drought have taught growers the importance of conserving water even during the wet years. "It's always on my mind and I'm constantly trying to tell people to get away from watering just to water," said Jensen.
Many wineries have implemented techniques such as burying their irrigation lines to save water. Dutton is using neutron-probe moisture meters to measure the quantity of water in the soil to determine how much irrigation they need. Like many vintners he also uses deficit irrigation to give the vines as little water as possible in hopes that they will produce smaller berries and better wine.
It could take years to replenish the state's depleted groundwater supply. Stored in cracks and spaces in the soil and rock, groundwater is a primary source of water during drought years. But as the drought dragged on, vintners had to dig deeper wells and access underground aquifers, which is raising environmental concerns in some communities.
In the semi-arid Central Valley south of Fresno, farmers traditionally rely on snowmelt and wells to support their crops, including grapevines. But Don Cameron, general manager at Terranova Ranch, is trying an old method to capture water during plentiful times in an attempt to recharge groundwater levels.
In 2011, Cameron tapped floodwater from the Kings River, submerging 1,000 acres of vines in up to 18 inches of water. He then allowed it to seep into the soil over the course of five months. The process didn't affect his vines during bloom or fruitset. Cameron says his plan is to capture and retain floodwater, instead of letting it flow into the ocean, for use during the dry years. The technique is gaining traction with his grower neighbors in the Central Valley and other areas.
California's water status may be looking up, but there are still several months left in the rainy season. Vintners know all too well that Mother Nature can turn off the rain at any time. "I don't think anyone is going to open the spigot, turn on the well pump and let it rip," said Ames. "Once you have it, you really have to protect [the water]."