Assumptions and Estimates for California Water Plan Update 2018

The California Water Plan (Water Plan) is the State government’s strategic plan for sustainably managing and developing water resources statewide for current and future generations. The Water Plan development process provides a planning framework for elected officials, agencies, tribes, water and resource managers, businesses, academia, stakeholders, and the public to collaborate on findings and recommendations and make informed decisions regarding California’s water future. The goal for each update of the Water Plan is to receive broad input and support from Californians, meet California Water Code (Water Code) requirements, guide State investments, and advance integrated water management and regional sustainability. 

This draft report and the related data posted online comprise the Draft Assumptions and Estimates Report (Draft A&E Report) for California Water Plan Update 2018 (Update 2018). The Draft A&E Report presents key assumptions and estimates, data and data sources, and companion plans that will be considered for the preparation of Update 2018. The report increases the transparency of the Water Plan process by disclosing the data, tools, methods, and references used to prepare Update 2018. This report meets Water Code requirements, which stipulate that the California Department of Water Resources (DWR) must publish the Water Plan’s assumptions and estimates one year prior to the plan’s publication, as well as provide an opportunity for public review and comment. Water code requirements for the Draft A&E Report are presented below. 

The Draft A&E Report also describes the approach DWR is taking to improve the analytical tools and data being used to develop Update 2018. DWR will continue to update Draft A&E Report content online during the remainder of the Update 2018 development process. A draft glossary for Update 2018 is included as part of this report, and the final version of that glossary will be published as a component of Update 2018. The final data and data sources will be included in the Update 2018 reference and technical information.