Wastewater to Irrigate More Vineyards

Sonoma and Napa agencies work to recycle treated water

by Paul Franson
drip irrigation
Photo courtesy UC Cooperative Extension, Sonoma County.
Healdsburg, Calif.—Vineyards around Healdsburg in northern Sonoma County will soon be irrigated with recycled water, the latest such project to put wastewater to practical use. Vineyards in other parts of Sonoma and Napa counties also receive recycled water, and plans are under way to expand that usage significantly.

The latest move came when the Healdsburg City Council approved a project to irrigate more than 300 acres of vineyards owned by Syar Industries with highly treated wastewater from the city’s new $32 million, state-of-the-art treatment plant west of town near the vineyards.

The reclaimed water could flow as early as next summer. Syar will get the water free for five years, if it uses a minimum 25 million gallons annually.

Reclaimed water has been used for years on winegrapes and other crops in parts of Sonoma County, but the city had to win approval of state water regulatory officials and address citizen concerns in order to allocate the water.

Recycled water in Sonoma Valley irrigates vineyards, pastures, golf courses and playgrounds; the regional wastewater system of county seat Santa Rosa provides more than 1 billion gallons of highly treated wastewater to irrigate more than 6,000 acres of farmland and vineyards.

Last year, north county residents and grapegrowers stopped the Sonoma County Water Agency's plan to use treated wastewater on farms and vineyards. Critics contended that using treated wastewater on thin, porous soils could contaminate groundwater and wells.

That project would have transported treated wastewater from Santa Rosa and Windsor using a system of 19 reservoirs and more than 100 miles to irrigate crops in Dry Creek, Alexander and Russian River valleys. The water agency postponed the projects due to lack of funds and customers.

Napa moves forward
Meanwhile, the Napa Sanitation District is taking steps to expand use of recycled water in Napa Valley. The district now supplies recycled water to vineyards at Eagle Vines and Chardonnay Golf Clubs, the vineyards at the Meritage Resort, and other properties in south Napa around the treatment plant: among them, a total of 688 acres of vineyards. The district produces an average of 2,050 acre-feet of recycled water at its Soscol water recycling facility each year.

One factor limiting the delivery of recycled water to new customers is the necessary pipeline delivery system, which is expensive to build because it must be completely separate from the potable water supply system.

The district is now constructing an oversized recycled water pipeline to Napa State Hospital for landscape irrigation and potential extension to the Milliken-Sarco-Tulocay area of Coombsville or east Napa, which is chronically short of water. That pipeline could potentially be paid for by prospective water users in the area, primarily vineyards and a golf course.

Federal economic stimulus dollars have accelerated this project.

Storage is a factor for recycled water, since demand is limited during the winter. Storage tanks or reservoirs would allow recycled water produced during the normally wet winter season to be stored until it is needed in the spring and summer. To provide this storage, some potential water users may have to provide on-site storage.

Carneros is short of water, too, but this would require a pipeline underneath the Napa River. The district has been looking at supplying vineyards in the water-short Los Carneros water district for 15 years. However, the cost would have to be paid by users such as the developers of the proposed St. Regis Resort at Stanly Lane.   
Likewise, a developer would like water for proposed vineyards on Soscol Ridge east of Soscol Road, but running pipes under the highway is very expensive.

With continuing water shortages expected in the future in much of California, recycled water is likely to become more popular for vineyards in the future.
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