The Santa Clara Valley Water District, and the County’s Many Other Water Agencies, Explained

How does the water you drink and use for washing and every other function get to you in Santa Clara County?

PUBLISHED SEP 13, 2021 12:00 A.M.
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Water in Santa Clara County is delivered by Valley Water, and numerous other water agencies.

Water in Santa Clara County is delivered by Valley Water, and numerous other water agencies.   Tom Sulcer / Wikimedia Commons   C.C. 1.0 Public Domain Dedication

Santa Clara County, like the rest of California, has a water problem. All 58 California counties have been declared disaster areas by the United States Department of Agriculture thanks to the seemingly endless drought throughout the state, and the National Integrated Drought Information System puts the number of Californians affected by drought at 37.3 million—close to the entire population.

With the sixth largest population in the state, Santa Clara County’s annual consumption of 306.4 million gallons of water is also the sixth most of any county. But in June of 2021, the county’s predominant water agency asked the 1.9 million residents who live there to dial down their water use by 15 percent from what it was two years earlier. 

County residents and businesses couldn’t get it done. Water consumption in the county dropped by only 6 percent. So what did the water district do about it? 


Even in the middle of a historic drought, water districts have no legal authority to impose rules that limit water. Their job is to get water to their constituents, which involves a variety of programs. As the Santa Clara Valley Water District, more commonly known as Valley Water, says on its website, “ensuring a reliable water supply for nearly 2 million people requires a multi-faceted approach.”

Valley Water: The Dominant Water District in Santa Clara County

Valley Water is the largest, but not the only water agency in the county. According to a report by the Santa Clara County Local Agency Formation Commission (LAFCO), the county is served by seven special water districts, and nine cities, which also deliver water to their residents. In addition, 11 private companies provide various water services in Santa Clara County, including San Jose Water Company, South Bay Water Recycling, and the Sunnyvale Water Pollution Control Plant.

Cities buy their water from the Santa Clara Valley Water District or from the San Francisco Public Utilities Commission (SFPUD). The city of Santa Clara Water Utility, for example, purchases water from both agencies, and runs it through 335 miles of pipe to the city’s residents. The city also stores 28.8 million gallons in seven tanks, and controls 26 wells.

The largest district in the county is also the oldest. Founded in 1929 as the Santa Clara Valley Water Conservation District, the district was formed by business leaders and farmers who fixed some serious issues with the county’s water supply. First, there wasn’t enough of it. Even in the early years of the 20th century, the region’s groundwater supplies were overdrawn.

This problem was compounded by another fact that needed to be addressed with some urgency. Namely, the valley was sinking. The phenomenon, known as “land subsidence,” occurs when groundwater and minerals are depleted from the ground below the surface. The new water agency created six recharge reservoirs to replenish the missing groundwater, and through that step and by bringing in water from sources outside the county, the sinking—13 feet between 1915 and 1969—was halted by 1970.

Valley Water is governed by a board of directors with one representing each of its  seven electoral districts. Each director serves a four-year term, with a limit of three terms each. Geographically, Valley Water’s boundary is the same as the Santa Clara County line. LAFCO estimates that the district serves 1,781,642 residents, which leaves roughly 200,000 for the county’s other six, much smaller water districts. 

None of the other districts, however, supply water wholesale. Valley Water is the only wholesale supplier in the county, selling water to cities and other districts that then act as retail sellers, directly supplying to, and billing, consumers. 

Santa Clara Valley Water District also serves a unique role as the county’s designated groundwater management agency. The district regulates all wells in the county, and provides free water quality testing for the water drawn from those wells. 

Smaller Water Districts Serve as Retailers 

The SFPUC also acts as a wholesaler in Santa Clara County, and is the sole supplier to the Purissima Hills Water District, which serves about 6,400 residential customers and 10 institutional customers over 13.4 square miles covering about two-thirds of Los Altos Hills and some unincorporated areas south of the town. The SFPUC, in turn, gets most of its water from reservoirs in the Sierra Nevada, primarily Hetch Hetchy. The Purissima Hills Water District, founded in 1955 and named for an area west of Los Altos where there were about 350 homes at the time, does not use groundwater at all.

Nor does it use recycled water, which according to the LAFCO report comprises about four percent of the county’s water supply. Instead, it stores the water it purchases from the SFPUC in 11 tanks with a total capacity of 10 million gallons. The district is governed by five directors, each elected to a four-year term.

The Aldercroft Heights County Water District, founded in 1958, is another water retailer, serving an unincorporated area in the Santa Cruz Mountains. The district serves 349 customers, according to LAFCO, over an area of just 0.18 square miles on the western edge of the county above Los Gatos.

The San Martin County Water District, formed relatively recently in 1988, serves 450 customers with drinkable—or as they say in the water business, “potable”—groundwater and is also the provider of water for use in fighting fires. Another small district, the Pacheco Pass Water District, overlaps with San Benito County. The district has been around since 1931, and its primary function is to “capture, store and release local water” to recharge groundwater levels within its boundaries.

‘Resource Conservation’ Districts Also Play a Role in Water Supply

The other two water districts in Santa Clara County are set up for purposes of water conservation. The Loma Prieta and Guadalupe-Coyote Resource Conservation Districts were started in 1942 and 1944 respectively, for the purposes of “soil conservation.” In 1971, all of the state's soil conservation districts received new mandates to focus on conservation of “resources,” including water. 

The districts “control runoff, prevent and control soil erosion, protect water quality, develop and distribute water, improve land capabilities, and facilitate coordinated resource management efforts for watershed restoration and enhancement,” according to LAFCO.

Even with the complex water delivery system in Santa Clara County and extensive responsibilities of Valley Water and other water agencies, there is still little they can do to force people to save water. Only cities can make those rules for their residents.

The problem is, each city implements different rules for how often residents can wash their cars at home, water their lawns, and perform other non-essential water-consuming activities.

“We do understand it can be a little bit confusing,” Valley Water executive Aaron Baker told the Mercury News. “We are encouraging the cities to implement their water shortage contingency plans as they are, but to unify the messaging.”

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