By Mike Hsu, UCANR

Study: Climate impacts widespread across California, fueling worries over water supply

As water system managers across California devise strategies to help secure their water supply, they often face a major obstacle to implementing those measures: a lack of interest or will to act among community members.

“One of the things that the literature has found is that even if water system managers and local decisionmakers are really worried about climate change and water security, a lot of the adaptation strategies that they have in their toolbox actually require support from residents,” said Kristin Dobbin, a UC Cooperative Extension specialist focused on water justice planning and policy.

Because popular support is essential for realizing many water-related adaptations – from changing the rate structure to approving bonds for new infrastructure – Dobbin and her colleagues recently published a paper looking deeper at residents’ experiences of, and concern about, climate impacts to household water supply.

Through a drinking water-focused portion of a long-term panel survey administered by California State University, Sacramento, scholars in the Household Water Insecurity Experiences research network had the opportunity to query Californians on how they are experiencing the climate crisis at their taps. Specifically, the researchers sought to analyze respondents’ perceptions of future climate risks to water security.

“As a group that studies drinking water access in California, we’re often looking at the system level and community level,” said Dobbin, based at the UC Berkeley Department of Environmental Science, Policy and Management. “So it was exciting to dive into the household level and understand what’s happening at a more individual level.”

Climate impacts seen ‘up and down the state’

The statewide survey, conducted in spring 2021, elicited 704 responses from the panelists, representing every census region in the state and nearly every county. More than one-third (34%) of respondents said that their water supply had been affected by an extreme weather event in the past five years. Given the timing of the survey, drought was unsurprisingly the most frequently mentioned impact. Importantly, these climate impacts were felt across California.

“There is an inclination to assume that drought and other impacts are a geographically bounded issue, but what we really see is that is not the case,” Dobbin said. “These impacts are happening up and down the state, all the way to the Oregon border.”

Overall, 85% of respondents reported that they were concerned about the long-term reliability of their water supply. Crucially, the study also indicated that residents were making the connection between climate impacts and risks to their future water security.

“The more impacts they reported, the more concerned they were about future supply and reliability,” said study co-author Amanda Fencl, a senior climate scientist with the Union of Concerned Scientists.

Droughts and heat waves, in particular, seem to increase residents’ concerns over water supply the most. Dobbin suggests that framing the need for water-security adaptation strategies around those specific weather events could be particularly useful in marshaling community support.

Knowing the level of concern within the community – and understanding the best way to convey the urgency of climate adaptation measures – could be a boon for local managers seeking to gain public backing for more expensive water projects. Such projects might include self-sufficiency measures that reduce reliance on imported water from other parts of the state.

“That could bolster some water managers to have more confidence in using climate change and extreme events as a way to motivate ratepayers to get on board with these bigger investment decisions,” Fencl said.

Study highlights avenues for more research

While flooding barely registered as a climate impact in the 2021 survey results, Dobbin said that the responses would likely be very different today, after atmospheric rivers inundated the state this past winter. Floodwaters can damage water treatment plants – and storms can knock out power to private wells and larger water system treatment and distribution facilities.

In fact, from the 2021 survey, power outages due to utilities’ wildfire prevention policies were the climate impact most frequently mentioned in the “other” category, highlighting for researchers the need to consider and plan for the interconnectedness of water and power systems.

“People forget about the interplay between a reliable electric grid and the ability to run water in your house and the ability for water systems to pump and treat water,” Fencl explained. “When we think about disaster response and disaster preparedness, we need to be a bit more holistic.”

The researchers also pointed to significant differences in experiences of climate impacts across gender and racial demographics, with Latino, Asian American Pacific Islander and LGBTQ+ respondents reporting higher rates of impacts. Given the relatively small sample sizes, however, Fencl said there needs to be larger – and more inclusive – surveys to get a clearer picture of those disproportionate impacts.

Even still, Dobbin added that their study serves as a reminder for scholars, water managers and policymakers to re-center community members, in all their diversity, as key players in the push for more effective and sustainable climate adaptation strategies.

“One of the takeaways from the paper is that we can’t forget about the role of the public in this conversation – and we can’t bypass the public,” Dobbin said. “The bottom line is that most of the adaptations that we have available to us require some level of residential involvement.”

In addition to Dobbin and Fencl, authors of the study, published in the journal Climatic Change, include Gregory Pierce, UCLA Luskin Center for Innovation; Melissa Beresford, San Jose State University; Silvia Gonzalez, UCLA Latino Policy and Politics Institute; and Wendy Jepson, Texas A&M University.