One State Agency’s Journey Toward Climate Resilience
Guest blog written by Andrew Schwarz and Romain Maendly, California Department of Water Resources
California is well known for its Mediterranean climate, swinging from cool, wet winters to hot, dry summers. While those conditions are great for skiing and outdoor wedding planning, they also drive extreme variability from year to year. Droughts and floods are a part of California’s hydrology in a way that is unmatched anywhere else in the United States. We have a saying here, “there’s no such thing as an average year” (it’s true, we have 5 defined water year types: wet, above normal, below normal, dry, and critical).
The California Department of Water Resources (CDWR) has been helping manage this variability for nearly 70 years. Today, CDWR owns and operates the largest State-owned water system in the world (the State Water Project) that delivers water to 27 million Californians and 750,000 acres of farmland. 1 in 12 Americans get some portion of their water from the SWP! CDWR also manages flood risk and groundwater throughout the State, distributes millions in grant funding, and updates the California Water Plan every 5 years. Managing these resources in the face of accelerating climate change has been and continues to be a major focus.
CDWR formally launched its climate change program in 2009—with its first staff dedicated to mitigating and adapting to climate change. In 2012, CDWR adopted the first phase of its Climate Action Plan to reduce greenhouse gas (GHG) emissions—the GHG reduction goals have been updated a few times since then, but CDWR, including operation of the State Water Project, is on track to be carbon neutral by 2035. In 2020, the second phase of its Climate Action Plan was adopted, establishing a department-wide policy requiring the analysis of climate change impacts for strategic planning documents, investment decisions, risk assessments, and infrastructure development. Phase 3 of the Climate Action Plan is a continuously evolving process that includes vulnerability assessment and adaptation planning for CDWR’s assets and activities. Later this year, CDWR will release the first State Water Project Climate Adaptation Plan, which will evaluate how key investments in the system can help secure safe, affordable water in the future. In 2023, the Journal of American Water Works Association featured an article about CDWR’s climate action plan that details how it was developed and some of the lessons learned through the process (A Climate Action Plan for the California Department of Water Resources).
One of the unique aspects of CDWR’s approach to climate action, especially among state agencies, is its embrace of the uncertainty around climate impacts on water resources and the investments that must be made to manage potential future conditions. CDWR has incorporated key elements of Decision Making Under Deep Uncertainty into its key planning functions[SA1] . System stress testing across a wide range of potential future conditions (often up to +5 degrees Celsius, +25% to – 25% average precipitation change, and Clausius Clapeyron scaling of up to 14%) are standard practice. CDWR recently worked with Dr. Scott Steinschneider to develop a weather generator customized to California’s weather regimes [SA2] that will further advance CDWR’s capabilities to evaluate novel hydrologic sequences for future planning, including longer more extreme droughts and more extreme floods.
Building on these efforts, later this year, CDWR will release its San Joaquin watershed studies. These studies look at projected climate change impacts and how strategies like Flood-Managed Aquifer Recharge and Forecast Informed Reservoir Operations can help reduce flood risk, improve water supply, replenish groundwater supplies, and support ecosystems in the San Joaquin Valley.
The tools we use to plan for climate change are important, but how we organize and implement climate adaptation will be just as important. Update 2023 to the California Water Plan [SA3] highlights three major themes: Addressing Climate Urgency, Strengthening Watershed Resilience, and Achieving Equity—highlighting a watershed-level approach to climate resilience that helps address inequities in water distribution and access. Via the CDWR’s pilot Watershed Resilience Program, local agencies will receive grants to support hand-in-hand work with CDWR to assess climate-related vulnerabilities and risks at a watershed scale and develop tailored adaptation strategies and solutions for climate resilience using cutting-edge climate science. The recipients will work through local watershed networks committed to inclusive engagement and participation.
While we are very proud of the work that CDWR has done, we haven’t done it alone. In nearly every case, we’ve worked with the academic community, local and regional water managers, and community groups that help teach us, guide us, and clarify what is needed. Our partnerships and collaborations are an integral part of how we co-produce science for management.
One exciting new project CDWR is engaging in is the COEQWAL California Water Management Project. Funded by a grant through the University of California Climate Action Initiative, the COllaboratory for EQuity in Water ALlocation (COEQWAL) is a two-year project that brings communities with diverse water needs together with collaborative research to explore new possibilities for water management in California. CDWR’s State Water Project Climate Action Manager and Lead Scientist are serving on the steering committee. The project is using CDWR’s flagship operations model, CalSim3, for most of its analysis. It’s a promising effort that we hope can lend important resources and expertise to explore potential paradigm-shifting possibilities for California water management with climate change.
Overall, CDWR’s efforts are aimed at addressing climate change challenges that will require built and natural infrastructure planning, investment, and innovation at federal, state, regional, and local levels. No single tool or strategy will work everywhere or for everyone. The suite of products CDWR has developed and will continue to develop, help provide at-scale analytical tools and adaptation strategies to meet current and future challenges for every level of government.