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.
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.