Ken Jenkins is the Chief Water Resource Sustainability Officer for Cal Water, an investor-owned utility that delivers water to millions of Californians in communities across the state. He’s leading efforts to improve water supply resilience in the face of worsening droughts and other climate change challenges.

Cal Water recently completed an in-depth climate change planning effort. What have you found, and what are the implications for building resilience and adaptation?

Cal Water has a broad geographic footprint, with 24 service areas in eight of the state’s ten hydrologic regions. We’ve long recognized climate impacts, but this new study took a deep dive into how, to what degree, and when impacts will occur in our service areas. We looked at a broad range of hazards that could worsen with climate change: drought, water quality degradation, extreme precipitation and flooding, sea level rise, extreme heat, subsidence, and wildfires.

We looked at the impacts of each hazard on four overarching functions of our work—assets/facilities, operations, supply, and demand, and over three distinct time horizons—early-, mid-, and late-century. We identified the consequences and likelihood of risks in each service area, and then developed an adaptation framework.

At a high level, we found things you might expect—droughts will become more frequent, longer, and more severe. We’ll see more intense weather patterns that will pose a risk to water quality. Floods in urban areas could cause service interruptions and damage to infrastructure. Yet there are striking differences across hydrologic regions and service areas in the pace, degree, and timeframe for these changes. We need to understand those differences to decide where to invest.

For instance, the length of drought is expected to increase, but that is most pronounced in the Tulare Lake and South Lahontan regions, where droughts are expected to be 50% longer by mid-century, and 80% longer by late century—as well as more frequent and intense. We had similar findings for the frequency and intensity of droughts.

We rated risks by likelihood and consequences. All of our service areas face at least six of the 14 risks we identified, which shows the broad impacts of climate change—we’re not facing one or two climate hazards but many at once. How do you best address them?

We knew water quality was big, but we were surprised to see it is the top risk—a result of more hot days without precipitation, increased wildfires, and extreme weather, like large storms after fire. This highlighted how important it is to understand and get ahead of the risks. With something like water quality, you can’t wait to address it until a problem occurs. If it’s occurring, you’re already behind.

How does this work connect with groundwater sustainability planning?

The short answer is that it’s all related: supply, demand, operations, and facilities. Long-term conservation has resulted in lower demand in the last 10–20 years. Our groundwater pumping is within sustainable levels at present, but we’re actively identifying opportunities for managed recharge to offset projected decreases in natural recharge. Good rules around basin accounting will help us move recharge forward.

What might this all mean for water affordability?

Affordability is one of three key pillars, along with conservation and reliable infrastructure, that allow us to serve the community. We identified a number of tools to help balance the cost of what needs to be done with the impact to affordability. Key to this is our assistance program for low-income customers, as well as rate design and system consolidation. Conservation also reduces demand, lowers operating costs, and reduces customer bills, and it continues to be a key part of our affordability planning.

We’re in the third year of a historic drought—how is that playing out across your service areas? What are some of the opportunities and challenges?

The drought is playing out differently across service areas. We’ve gotten ahead of most of the significant impacts through operational changes, firming up supply availability and increasing messaging and programs around the need for reductions early on. We face significant challenges as a supplier, but we have the ability to address them—it’s a matter of finding out what we need to do. We all need to reduce demand to help the overall system. It’s going to take cooperation between a lot of different entities and stakeholders. It’s an opportunity to come together as a water community.