Climate Vulnerability and Adaptation Study for California: Legal Analysis of Barriers to Adaptation for California’s Water Sector

This project focused on the legal and institutional framework associated with California’s water rights allocation system, and identifies changes to that framework that would facilitate adaptation to climate change. Since such changes may be difficult to accomplish, the project focused largely, but not exclusively, on changes that may be politically feasible now or in the future. There is already conflict in California over water allocation, and climate change will exacerbate that conflict by increasing demand and decreasing supply. Adaptation will be needed both to address already unavoidable impacts from historical emissions, and to address impacts from future emissions. To identify changes that would facilitate adaptation this study looked at recent legislation, policy proposals, and white papers addressing water reform; and off‐the‐record interviews were conducted with individuals familiar with California water law. Having an accurate record of who is diverting water in California, and in what quantity, is the single most important step towards preparing for climate change, and the recommendations reflect that. For groundwater, the changes identified would (1) expand groundwater monitoring and reporting requirements, (2) expand groundwater planning requirements, and (3) require the State Board to improve groundwater management and to prevent the waste or unreasonable use of groundwater. For surface water, the changes we identify would (1) require the State Board to provide information about efficient agricultural water management practices, and streamline State Board procedures for enforcement actions for the waste and unreasonable use of water, (2) increase the enforcement of and penalties for failing to file a Statement of Water Diversion and Use and for illegal diversions, (3) require all beneficiaries of the water rights system to bear the cost of activities related to the administration of those rights, and (4) expand reporting requirements to require diverters to state what they believe their water rights to be