California's agriculture sector is struggling as the state heads through a fourth year of drought. Water tables are shrinking and state water project allocations are at near record lows.
The Central Coast's two largest crops are strawberries and wine grapes. Vineyards do have the ability to go into survival mode during dry spells, but managing that period is a tricky and a scientific game.
It's springtime in San Luis Obispo's Edna Valley where vineyards are, by far, the dominant crop. During our visit, the vines at Wolff vineyards were in the mid-flowering stage.
"We have chardonnay, we have riesling, pinot noir, syrah, petite syrah and teroldego," said Jean-Pierre Wolff, the man behind this family-run vineyard and winery. "I tell people I sell fruit by the ton and I sell fruit by the two pound in a bottle of wine in a fermented form. I consider my tasting room, my fruit stand."
When Wolff acquired the vineyard 17 years ago, drought was not a main concern, but he says he realized the value of water so he decided to take an unconventional approach for his vines.
"The whole concept behind the dry farming is using the winter rain as a storage in the ground and then you pull the water from the that winter month's accumulated water during the summer months and then you replenish for next year," said Wolff.
The vintner has eased into this method, starting with his chardonnay vines—vines that have been on the property since it was originally established 40 years ago.
"I did not turn off the spigot overnight but gradually weaned them out of water to a point where I was able to strictly rely on annual rainfall," Wolff said.
Wolff's vines are near the coast and that helps keep moisture in the vines during the summer months. But, those growers who aren't located in such favorable climates find dry farming to be more of a challenge or just not feasible at all.
Steve Lohr is the Chairman and CEO at JLohrVineyards, which grows the bulk of its wine grapes in the eastern Paso Robles wine growing area.
"You only get about 12 to 14 inches of rain per year and the soils are gravely and sandy so there's not as much water holding capacity," said Lohr.
Instead of using dry farming, Lohr waters his plants a little bit more during the spring, a time when the heat isn't taking the water out of the soil.
"That water goes down deeper, those roots chase that water down, so rather than water weekly as we did years ago, we can go through the months of June and July and not water at all," Lohr said.
Lohr also uses a tool known as pressure bombs—small bags placed around the leaves in the morning that help measure how much water the vines need, if any.
The Central Coast is also home to a certification standard that helps consumers know which wineries are working to reduce their water footprint. The wines are SIP (Sustainability in Practice) Certified.
Kris Beal helped develop the standard. She says the requirements for a vineyard to be certified by the program are reviewed annually making sure that the standards are relevant and address current issues.
"From the beginning, the standards have required multiple practices in terms of water conservation, these have all been in place before the drought," Beal said.
The vineyards have to provide the program with multiple pieces of information in terms of their irrigation decisions, based on soil, climate and plant needs.
"Really, it's the irrigation scheduling, that collecting that information helps to inform those decisions so that you're matching the applied water to what the plant needs," Beal said. In addition, she says the program requires maintenance oversight of the irrigation system to assure that there aren't any failures or leaks.