Why isn’t rainwater capture more popular in Sonoma County’s wine industry?

When Steven Lee’s well nearly ran dry in 2020, the senior scientist at the Sonoma Ecology Center faced a conundrum: He could either dig a new well at his Glen Ellen home — the fourth on the property since the 1970s — or he could tap into a new resource: the rain.

Lee, whose job involves monitoring the Sonoma Creek watershed, knew digging a new well would negatively impact the already-depleted groundwater. Also, the new well would have to be dug extra deep, where the water could be contaminated by dangerous levels of arsenic and boron.

“Deep wells can be incredibly expensive to install, and they don’t give you assurance you’ll have adequate water,” Lee said. “Local property owners and vineyards with deep wells often have to treat the water before they can even use it.”

So, Lee chose the rain.

Today, a 70,000-gallon rainwater catchment system satiates his property’s small family farm, including the livestock, garden, fruit orchard and landscaping.

During a storm, the rain is collected as runoff from the roof, then fed by gravity into several 5,000-gallon tanks throughout the property. One inch of rain on a 1,000-square-foot roof yields about 600 gallons of water. In an average year with 30 inches of rain, that’s 18,000 gallons of water.

This year, Lee’s rainwater tanks are already full.

Water into wine

In November, Lee helped install a 20,000-gallon rainwater harvesting system at Flowery Elementary School in Sonoma. The hope is that it will demonstrate the feasibility of installing the system at other local schools.

“School properties are a great place to capture rainwater because they typically have large roofs,” Lee said. “If a school plans ahead, it could collect enough rainwater during a typical rain year to water its athletic fields all summer.”

For Sonoma County’s wine industry, which continues to seek innovative ways to grapple with the state’s crippling drought, rainwater capture could be a meaningful step towards reducing its water consumption, too.

Wineries and most vineyards use immense amounts of water, not just for thirsty vines, but also for frost protection, barrel washing, tank and equipment cleaning, cooling systems and other uses.

Lee said a winery with ample roof space, ponds or other catchment vessels like open-top tanks would be a prime candidate for harvesting rain.

“A large winery or warehouse could collect a couple hundred thousand gallons of water each year that would otherwise be pumped out of the ground,” he said. “The rain captured off the roof could be fed into a pond then used for irrigation in the vineyard. I think it’s great idea for wineries.”

Yet despite the years-long drought, few wineries take advantage of rainwater capture. For some, the infrastructure is too expensive. For others, it’s due to storage space constraints. For many, however, its a lack of resources and incentives directed at the wine industry.

Lost resources

In Sonoma County, where the ebb and flow of drought is a familiar aspect of residency, rainwater capture is a fledgling practice among most residents and even fewer commercial businesses, including wineries and vineyards.

In 2012, Gov. Jerry Brown approved the Rainwater Capture Act, authorizing residential, commercial and government landowners to collect, store and reuse rainwater for landscape irrigation, outdoor water features, industrial processing and other uses. In 2017, Sonoma County approved rainwater for potable use, including drinking and cooking — given certain safety protocols are met.

For residents interested in rainwater catchment, an abundance of resources and incentives exist from local organizations like the Sonoma Ecology Center, Gold Ridge and Sonoma resource conservation districts, Daily Acts, American Rainwater Catchment Systems Association, Sonoma Water and the Sonoma-Marin Saving Water Partnership.

For wineries, vineyards and other agricultural businesses, however, resources are scant.

“There aren’t any specific resources for the wine industry that I can think of, since grant funding depends so much on location and benefiting natural resources versus industry,” said Jessica Pollitz, an engineer with the Sonoma Resource Conservation District. “In most cases, rainwater collection is an expensive capital expenditure that needs an equally valuable benefit.”

At the Gold Ridge Resource Conservation District, a nonprofit focused on environmental stewardship in Sonoma County, Deputy Director Noelle Johnson said her organization has helped build rainwater catchment systems for a handful of agricultural properties, including a dairy.

They haven’t worked with any wineries or vineyards, however.

“They generally require way too much water for tanks, and pond construction is a rare feat,” she said. “They’re difficult to permit, very expensive, and most wineries don’t seem to have the space for them.

“We’ve had some wineries express an interest in building roof rainwater systems using tanks, but given it would supply some minute fraction of their water needs, it would really feel more like ‘greenwashing’ than true resource conservation, so we’ve never pursued the idea.”

A model for change

For Jackson Family Wines, who launched a 10-year sustainability and climate action plan called Rooted for Good in 2021, water conservation is integrated into production.

Since 2008, the Santa Rosa-based company has reduced its water intensity (the amount of water used to produce wine) by 54% at its 40-plus wineries. Part of that is thanks to rainwater, which they collect and reuse multiple times.

At the company’s La Crema Estate winery in Windsor, rainwater is captured from the roof of the tank cellar, then funneled into 10 open-top wine tanks, which would otherwise sit empty in winter through early summer. The water is transferred to closed-top tanks for storage, then filtered and used in the facility’s cooling tower throughout the year.

“The cooling tower is responsible for about 20% of the winery’s overall water usage,” said Jim Sturgeon, La Crema’s general manager. “Rather than pull that water out of the aquifer, we use rainwater that can be recycled up to seven times. It’s definitely the best intended use of the water.”

This year, the winery has captured 50,000 gallons of rainwater so far, with the capacity to store a total of 200,000 gallons. Sturgeon said La Crema is fortunate to have the tank capacity and storage space for the extra water.

“Water is a huge resource for us, so rainwater capture and water recycling are a big part of our conservation efforts,” said Sturgeon, who helped create Jackson Family Wines’ water efficiency goals as part of Rooted for Good. “It’s a part of the company’s culture to have a sustainability focus in everything we do.”

Water independence

While some wineries don’t have the storage capacity for 200,000 gallons rainwater, they are still finding ways to use the vital resource.

At Medlock Ames winery in Alexander Valley, five ponds on the Bell Mountain property rely solely on rainwater, which is used for irrigation, fire suppression and the support of animal habitats.

“While we have ponds and wells, we recognize water isn’t an infinite resource,” said Julie Rothberg, president of Medlock Ames. “One of the best ways to avoid unnecessary water use is to keep as much moisture in the ground as possible. Creating healthy soils that can absorb and retain moisture over the span of a vineyard has massive water-saving potential.”

Ames Morison, the co-founder of Medlock Ames who has made the winery’s sustainability goals his full-time job, said the industry needs to learn to make better use of the water they do have access to.

“The rainwater in our reservoirs falls under the jurisdiction of the State Water Resources Control Board,” he explained. “Landowners can get permits to use that water, but those permits can be suspended in drought years, like they were in 2021 and 2022.”

As part of Medlock Ames’ five-year sustainability plan, the winery hopes to reduce its water dependency by 40%. For them, that means delving into regenerative farming and its promise of retaining soil moisture by increasing organic matter.

“Every 1% increase in soil matter allows the ground to hold an additional 17,000 to 25,000 gallons of water per acre,” Morison said. “Our aim is to ramp up our soil organic matter to the point where we no longer need to irrigate.”

The power of recycling

Given the high water requirements of the average winery or vineyard, some argue rainwater capture doesn’t provide enough water to be worth the time, space or investment.

At the UC Davis Teaching and Research Winery, researchers are trying to change that. Ron Runnebaum, associate professor at UC Davis in the Department of Enology and Viticulture and the Department of Chemical Engineering, is about to launch a research project on rainwater recycling.

Using a method called “clean-in-place,” the process could allow rainwater to be recycled up to 10 times, even if cleaning compounds have been added.

“It takes approximately 5 gallons of water to make 1 gallon of wine, depending on a winery’s cleaning efficiency and the size of its tanks,” Runnebaum said. “Water is such a scare, costly resource. We’re hoping to demonstrate rainwater capture and reuse can give wineries more control over their total water usage.”

Looking forward

While harvested rainwater isn’t intended to be used by residents or businesses as a primary water source, it can help bridge the gap between the wet and dry seasons — especially during a drought.

For Steven Lee of Sonoma Ecology Center, who is about to launch a new rainwater-capture project at Altimira Middle School in Sonoma, the county’s water resources remain front of mind.

Looking forward, he hopes to see more focus on recharging the groundwater in our local aquifers, which would benefit the entire community.

“In the meantime, I think schools, wineries and vineyards are the perfect place for rainwater capture,” he said. “Wineries that have the dollars and the space just need the help and motivation to make it happen.”

You can reach Staff Writer Sarah Doyle at 707-521-5478 or sarah.doyle@pressdemocrat.com.