Online tool assesses drought risk for residents on private wells, public water systems

Community Water Center launches web tool to help residents identify if their home will have access to clean water when the next drought comes

By Reggie Ellis

VISALIA – California is doing more to preserve its groundwater levels than ever before, but a new, interactive tool by a local water advocacy group suggests it may not be enough. 

Last Wednesday, Visalia-based Community Water Center (CWC), an organization that strives to educate, organize and solve water problems in disadvantaged communities, argueD that California will experience longer, more severe droughts due to climate change. This will cause drinking water supplies for vulnerable communities to run dry or become contaminated, directly threatening California’s ability to secure safe and affordable drinking water for all of its residents.

“It’s not a matter of ‘if’ another drought hits, it’s a matter of ‘when’ it hits,” said Susana De Anda, executive director and co-founder of Community Water Center, a non-profit based in Visalia aimed at ensuring safe, clean, and affordable drinking water for all Californians. “That’s why we created the drinking water tool. So that communities and decision-makers can better prepare to protect drinking water during these changing times.”

The drinking water tool, which can be found at, is a web-based application that can help residents learn:

  • Where their water comes from based on your address
  • Whether a future drought could impact their drinking water supply
  • About the groundwater quality and supply in their area
  • How to advocate for safe, clean and affordable drinking water
  • How to compare information about their water with their local Groundwater Sustainability Plan.

For example, if you live in Woodville, Calif., you are connected to a community water system known as the Woodville Public Utility District, your water use will be monitored by the Lower Tule River Irrigation District under the new rules regulating groundwater from the Groundwater Sustainability Act approved in 2014, all of your water is supplied from pumping groundwater. 

The contaminant levels of each water system are based on a nine-year average from the years 2005-2013. Keeping Woodville as the example, the water contamination tested below the state’s maximum containment level (mcl) for arsenic, nitrates and 1,2,3-Trichloropropane, a man-made chemical typically found at industrial or hazardous waste sites. There is currently no mcl for hexavalten chromium, a cancer-causing byproduct of industrial metal working. 

More importantly, the tool attempts to assess the drought risk of private wells for residents who are not part of a municipal or community water system. Regionally, the San Joaquin Valley has the largest total population reliant on private wells, those independent of a community water system, with an estimated 527,570 people getting their water in these domestic well areas (DWA). However, as a fraction of the population in each region, that represents 13.3% of the Valley’s population, much less than the Eastern Sierra and Northern CA where populations relying on domestic wells represent more than one-third (37.8%) and more than a quarter of residents (28.4%), respectively.

During the last drought, the average water level depth of private wells in the Central Valley dropped from 100 feet to 140 feet. If the Valley were to experience another, similar drought well water depths would be expected to drop to 170 feet. In Woodville, this would mean that eight wells would be in danger of running dry. If the drought is half as long as the 2012-2016 drought, private well would only drop by about 10 feet, meaning Woodville could expect that all of its wells would continue accessing water at their current depths.

Based on an analysis developed for this tool, 1.6 million Californians live in areas served by private domestic wells. Many of these residents live in the Central Valley and would be affected by future droughts. The Drinking Water Tool estimates that a future drought could impact 4,500 domestic wells in the Central Valley, potentially costing the state about $115 million. This presents a serious public health crisis and undermines California’s efforts to secure the Human Right to Water for all Californians.

The findings highlight why it’s critical to enact California Department of Water Resources’ drought recommendations and why CWC will introduce legislation this month, along with other stakeholders, to require drought planning for small water suppliers and communities reliant on private wells.

“Access to safe drinking water is a basic human right,” De Anda said. “We don’t want a repeat of the last drought, which left vulnerable communities in the San Joaquin Valley devastated without access to clean drinking water. We must make sure California is ready to protect access to drinking water when the next drought hits.”

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