DRY SPELL

Water covers most of the earth’s surface, and the notion that we could “use up” all of the blue planet’s H20 once seemed preposterous. For most of us, fresh water’s importance and limited supply didn’t really sink in until climate change highlighted extreme weather phenomena and this essential-to-life resource went into a state of permanent crisis.

The world’s thirst for fresh water is on course to outstrip the earth’s supply by the end of this decade, by an astounding 40 percent, according to a landmark report by the Global Commission on the Economics of Water published before the United Nations Water Conference in March 2023. Much of that demand comes from farmers. Food production alone has increased by more than 100 percent in 30 years, and agriculture accounts for about 70 percent of the world’s freshwater withdrawals, according to the UN. Meanwhile, climate change has made the deficit even more profound, and is putting more pressure on regions, in the forms of unusual extreme storms, heavy rains and intense droughts.

But what does that mean for wine? While estimates vary considerably (872 gallons of water for every gallon of wine produced is commonly cited), a great deal of water is utilized in the growing and production of wine, from the field to the cellar, where equipment, storage vessels and floors must be cleaned on a daily basis. Vintners who are eager to reduce their water usage are considering a number of solutions. While the water required in the cellar is definitely a factor producers are assessing when trying to reduce their consumption, water used for irrigation is generally a much bigger contributor to the increasing water shortfall vintners are facing across the world.

Wine regions almost everywhere tap freshwater – at least occasionally. While it is commonly believed that European wine regions forbid irrigation across the board, there are many regions where irrigation is either allowed all the time, or in certain cases, such as when vines are young or there has been a severe drought. In recent years, restrictions have been lifted in Bordeaux, Provence and Languedoc – regions where irrigation is anathema to their traditional approach to viticulture.

Meanwhile, irrigation has made winemaking possible in places like Southern Australia (portions of which get six inches of rain a year) and the Central Valley in California (which gets an average of five inches in the most southerly portion). While broad restrictions on irrigation have not yet been put in place, there are rumblings in drought-ravaged places like California, of impending limits. In the meantime, vintners are doing what they can do to reduce and optimize their use of water in the vineyards and beyond.

GOING DRY

Grape-growers considering either reducing or eliminating irrigation are understandably concerned about how less water will impact yield and overall wine quality. But reducing irrigation levels during droughts results in better wines, without affecting their crop yields, as long as they stay within certain parameters, a 2021 study from University of California, Davis, published in the Frontiers of Plant Science, has found. 

“We applied three different irrigation regimes at a Napa Valley vineyard growing Cabernet Sauvignon,” one of the study’s authors, Dr Cliff Yu, assistant professor of viticulture at California State University, Fresno, explains. The study covered the rainier vintage of 2019 and the bone-dry vintage of 2020.

“We focused on evapotranspiration, which measures water lost to the atmosphere from the vineyard,” Dr Yu says. “Then used irrigation to replace 25 percent, 50 percent and 100 percent of what had been lost by evapotranspiration. We found that wine quality and berry composition actually improved with just 50 percent replacement, with no yield loss. When we replaced 25 percent we had a yield loss.”

Sean Davis, vintner and co-founder of Marshall Davis Wines in Yamhill-Carlton, Oregon, says that Dr Yu’s findings reflect his personal experience. “We stopped watering our vineyard in 2016,” Davis says. “We find that dry-farmed grapes are better. Not only is the quality of the wine better, but they’re healthier and more resilient overall because the roots of the vines are forced to go deeper to find water.”

Deep Roots Coalition (DRC) was founded in 2000 in Oregon with the goal of eliminating irrigation from vineyards completely. “Irrigation is not a sustainable method of farming, and it also prevents the true expression of winemakers’ terroir,” says Cameron Winery president and DRC co-founder John Paul. “And irrigation really only began in the 1970s. Growers have been making wine without irrigation for thousands of years.”

When asked about the many regions that might not be able to cultivate grapes without irrigation, he points to Santorini in Greece, which gets about 10 inches of rain annually and has managed to produce incredible wine for more than 2,000 years. “We work to educate growers about how to dry farm,” Paul says. “You can’t just eliminate all irrigation immediately. You have to do it over time, and sometimes years. But it can be done. We are also focused on educating consumers. We hold a tasting every year, and that’s where we found we really got traction, because members of the trade and media tasted how much better dry farmed wines are.”

Brian O’Donnell at Belle Pente Vineyard & Winery in the Willamette Valley was a founding member of DRC, and concurs that it is really the “only form for sustainable viticulture.” When he planted his vineyard, knowing that he would want to dry farm, he initially put 12 Pinot Noir with different rootstocks in the ground across 1.5 acres. “From what we saw and through talking to others, we landed on 3,309 and 10,114,” O’Donnell says. “They work well with dry farming because they get down deep into the soil.”

The Emeritus Vineyards in California’s
Russian River Valley converted the 111-acre Hallberg Ranch and 31-acre Pinot Hill in 2011 and 2013, respectively. The process has not always been smooth. “When we initially started transitioning to dry farming, our yields went down by 30 percent,” vineyard manager Kirk Lokka says. “But after three years, the vines bounced back and we were producing 3 tons per acre again by 2011, at which point the transition was complete.”

“The effect on quality cannot be overstated,” Emeritus president Mari Jones says. “The berries and clusters are smaller, and that results in deeply concentrated wines. Complexity of flavors and aromas continues to increase year after year as the roots continue to grow deeper into the soil.”

HALF THE BATTLE

Not everyone is ready to completely swear off irrigation, and there are a range of creative solutions being put in place to drastically reduce growers’ reliance on groundwater. “Dry farming is a great slogan, but it’s really tough to do in California. In Oregon and Europe, where there’s more rain, it’s easier,” says
Randall Grahm, co-founder of the Central Coast of California’s The Language of Yes with Maze Row founder Joe C. Gallo. “But I’ve still been able to implement several strategies to reduce our reliance on irrigation. Drip irrigation does create a dependency for plants, because it’s like growing grapes in a flowerpot. They won’t grow deep roots that way, and with a limited root system they are less resilient to temperature fluctuations.”

Every year, he reduces irrigation in The Language of Yes Rancho Réal Vineyard in the Santa Maria Valley and his own Popelouchum vineyard, near San Juan Bautista. To reduce reliance on water without cutting it completely, while also encouraging deeper root penetration, Grahm moved the drip line from above the plants to between them, within the rows. “This system cuts the water usage by about 50 percent, and creates a moderately stressful environment for the plants, which creates better plants,” he says.

At Saint Clair Family Estate in Marlborough, New Zealand, with 230 acres under vine, general manager and winegrower Jarrah Prior is also focusing on “optimizing and reducing” water use, instead of eliminating it completely. “We recently set up side-by-side trials of subsurface vs. above ground irrigation,” Prior says. “With subsurface irrigation, it looks like you can reduce water consumption by about 30 percent.” He also ensures that vineyards are set up to thrive, by planting drought-tolerant rootstocks like 3309 and S04, and carefully mixing and matching terroirs and varieties.

“It is clear that Sauvignon Blanc does not respond well to water-stress, so we focus on low-lying, fertile soils that require very little irrigation,” Prior notes. “But Pinot Noir responds well to medium stress, so we plant Pinot within the Southern Valleys of Marlborough, with drier, clay-based soils.” And instead of providing vines with a slow, steady drip of water, Prior says they focus on “long and deep irrigation cycles, which encourage our vines to drive their roots deeper into the soils.”

At Natus Vini in Alentejo, Portugal, founder Hamilton Reis farms vineyards with a combination of dry and limited irrigation. “Our Natus Vineyard was just planted in 2018, and the last few years have been really dry, so watering has been crucial,” he says. “But we water in a very specific way, with the goal of eventually dry farming completely.”

Like the team at Saint Clair, Reis says his crew waters less frequently, but when they do, it’s intense. “Because we go long periods without irrigating, the top soil dries out, and the roots go deeper,” he explains. “This allows us to build up resilience slowly without harming yield.”

Reis has set up rainwater capture systems, which is then directed to a holding pond for future use. But he is most focused on farming adjustments, saying: “We plant cover crops that help us infiltrate water into the soils, and we focus a lot on canopy management. A big canopy will use more water, and will not necessarily produce more or better grapes.”

EXTRA MILE

Some wineries, like Oregon’s Abbott Claim in Yamhill-Carlton, which already dry farms, go a step further by aiming to optimize the water used in the cellar to clean tanks and barrels and sanitize equipment. When plans for the winery’s construction were created, the management team worked with architect Larry Ferar to reflect their sustainable and organic vineyard practices in the building itself.

The solar-powered winery opened in 2020, with a plan in place to recycle used water via worms. Abbott Claim hired BioFiltro to bring its patented winery wastewater cleaning system to the winery. Essentially, the company sets up a shipping container repurposed as a worm hotel on the estate grounds, runs the winery’s wastewater into it, and then uses the soft-bodied small land animals to clean that water.

“The winery’s production wastewater, generally too low in pH and too high in BOD [biological oxygen demand] and ammonia to be reasonably discharged in nature as is, is oxidized, pH-corrected and filtered by earthworms,” says Alban Debeaulieu, wine-maker at Abbott Claim. The water gets filtered through a layer of wood shavings, and the worms “clean” it by gobbling up the leftover sugars, skins and other production byproducts.

That water, which is then technically cleaner than required by Oregon law, gets pumped into a holding pond, and is then used in their organic spray program, Debeaulieu explains. “Every two or three years, we harvest the earthworms’ castings, which we integrate into our compost and spread in the vineyard to support vine growth.” Using the worms’ digestive effluvia as nutrient-rich fertilizer closes the loop and ensures there is no waste.

Clearly, there is a lot to think about, and many opportunities for action if vintners want to reduce their water footprint in the vineyard in the cellar. If climate change continues to wreak havoc on weather patterns across the world, or if governments respond to current drought concerns with rules that limit water usage, they may not have a choice.

“I don’t know if completely dry farming will ever take hold, but the ongoing problem of water depletion is real,” Grahm says. “We have become accustomed to no limits on water usage, but there will be a reckoning. Either we will run dry or there will be severe limits.”