Recycled Water Now an Option for Napa Vineyards

Pipelines bringing water to areas of southern Napa County

by Andrew Adams
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Purple pipes like these are now carrying recycled water that can be used for irrigation throughout the Carneros AVA in southern Napa County.

Napa, Calif.—El Niño may have brought much needed relief from years of drought this winter, but growers in southern Napa County are toasting a new source of water that’s a little more reliable than oceanic currents.

Earlier this month, the Napa Sanitation District celebrated the completion of nearly $50 million worth of projects to provide more recycled water for vineyard and landscaping irrigation. Napa’s Soscol Water Recycling Facility is located on the bank of the Napa River just south of the city. From Nov. 1 to April 30, treated wastewater is discharged into the river, and during the rest of the year it’s stored in treatment ponds or used for irrigation.

The expanded network of pipes will enable the district to deliver more recycled water to more properties in the Coombsville and Carneros appellations. The Coombsville pipe was finished in 2015, and the Carneros project was just recently completed.

Jimmy Kawalek, president of the Coombsville Vintners and Growers, said the “vast majority” of the group’s members have not connected to the the Milliken-Sarco-Tulocay pipe, which brings recycled water to the area. He said most members report it’s too expensive to connect their property, or they’re not in the service area. 

In Carneros, water had been an issue long before the region earned its reputation for producing quality Pinot Noir and Chardonnay grapes.

John Stewart is the president of the Los Carneros Water District and owns a 20-acre property that was part of what had once been a much larger ranch owned by his family. He said the idea of bringing recycled water to Carneros first arose in the 1960s and gained more attention during the drought years of the late 1970s but never went anywhere. “For whatever reason, the project never really gained traction,” he said.

Stewart is a retired civil engineer and was the Napa Sanitation District manager in the 1990s. After he retired in 2004, he became the president of the Los Carneros Water District and helped set in motion the process of getting a recycled water pipeline built.

The first step was an assessment for a feasibility study that informed the district who was interested in such a project. That led to a design assessment on 150 parcels in 2009 and early 2010.

Around the same time, the developers of a resort and winery project announced plans to dig a pipe beneath the Napa River to supply their property with recycled water. (Napa’s wastewater treatment plant is on the far side of the river from Carneros.)

Stewart said the district worked with the hotel developer and the sanitation district to get the size of the pipe under the river enlarged to accommodate water deliveries throughout the Carneros region. “If we designed it and funded it, they would build it and take over,” he said. “It was just a wonderful outcome. I was so happy about it.”

Once construction on the pipe from the treatment plant to Carneros was complete, work began in March 2015 on the 9 miles of pipe that would serve the property owners who voted to receive water. Stewart said the project received the support of 107 property owners covering 4,127 acres. Construction on the pipe finished in March.

Stewart said parcel sizes range from 1 acre to 360 acres, and he believed two to three properties may already have tied in to the system with nearly 30 applications awaiting review by the sanitation district.

Once a property owner has received approval from the district, they need to pay to build a connection to the main pipeline. Stewart estimated that cost to be between $5,000 and $10,000. Each property owner is allotted one-quarter acre foot of recycled water per acre per year and must submit an annual irrigation plan to the sanitation district. The entire system is designed to deliver 1,300 acre feet per year.

The project cost $16 million, with construction amounting to $10.5 million. About 45% of the total cost was covered by grants. Stewart said the district was able to get a low-interest loan from the state water board and because of the grants and few extra costs during construction the per-acre assessment for property owners may be around $120. “We’ve done really well for a bunch of volunteers,” he said.

The recycled water should help growers ensure a consistent crop each year, is a sustainable supply, results in less diversion of surface water, reduces the demand on groundwater and helps prevent saltwater intrusion from the nearby San Pablo Bay. “When my neighbor uses recycled water for irrigation rather than his well, it’s better for my well,” Stewart said.

The recycled water can be stored in reservoirs as long as those are separate from the local watershed. State water regulators do not allow recycled water to be stored in “on-stream” reservoirs. Property owners with ponds that are tied to creeks or wetlands can’t top those off with recycled water or use them to store recycled water.

Dyan Whyte, assistant executive director for the San Francisco Bay Regional Water Quality Control Board, said recycled water is perfectly suitable for irrigation but can still pose a risk for aquatic life because it is treated with chlorine. If recycled water is flushed out of a reservoir into a creek or a river, it could kill fish. Whyte added that the Napa River watershed is home to salmonids that are particularly sensitive to chlorinated water.

She said the Sonoma County Water Agency is organizing a pilot program to study the issue, which hopefully will lead to a more “straight forward” process for property owners to augment surface water storage with recycled water.

Jennifer Thomson manages her family’s vineyards on Los Carneros Avenue and Monticello Road. Thomson is the fourth generation of her family to farm in Carneros and said they have been lobbying for recycled water for decades.

“When casting my vote several years ago in support of the project at a public hearing I stated that although the parcel I was voting on behalf of had substantial and adequate irrigation water already serving it, I would vote yes in support of the community and project only if I could turn on a spigot in my lifetime,” she told Wines & Vines in an email. “Three previous generations of the Thomson family had supported this project with little to no traction and support from legislators, and it is truly amazing to see such a long-standing and talked about project come to fruition in just a little under three years—and in my lifetime.”

While it is not quite as simple as turning on a spigot, Thomson will be able to take advantage of the water in her lifetime. She said she needs to get a permit and water-use agreement approved as well as build the physical connection to the main pipe. Thomson said her reservoirs are full enough, so she’ll wait on building the tie-in to the pipe.

Despite the added costs to get the water, knowing she has a stable source of supply of water is invaluable.

Using recycled wastewater for irrigation may require growers to pay more attention to nitrogen and salt levels in the soil, but Thomson said almost any water source requires some type of adjustment. “I would prefer to adjust recycled water for my agricultural applications—which in my opinion is actually nearing potable water standards—than have no water,” she said.

Since the pipe was completed, Stewart said he’s heard from a few property owners who didn’t vote for the water assessment but are now interested in receiving recycled water. He said the district wants to see how the system works for a few years before expanding it with another assessment. “We want to run this thing for a year or two to see if the wheels come off in the corners, and we’ll see if there’s room for more people,” he said.

Expanding the system would likely entail building a pump station, and any property owners wanting join the system would have to shoulder those construction costs. 


Posted on 05.11.2016 - 08:33:48 PST
Recycled water is a great idea. I am curious if vineyards that are certified as organic or biodynamic can take advantage of the recycled water and still maintain certification. I think certification should stay in place, but if I'm not mistaken, certification currently does not allow for the use of recycled water. Can someone answer this question?
Steven Kolpan

Posted on 05.11.2016 - 11:35:34 PST
Would be even better (and far less expensive) if wineries could recycle and re-use the existing water from their operations like barrel wash. That purple pipe network is pricey.
Joshua Miller

Posted on 05.11.2016 - 14:00:14 PST
Good question Steven, I forwarded it along to the folks at the California Certified Organic Farmers who tell me that any water that meets "state, federal and local requirements for irrigation is allowed in organic systems."
Andrew Adams