Annual Water Supply and Demand Assessment

DWR has written the Annual Water Supply and Demand Assessment Guidance to help suppliers prepare their Annual Assessment and submit an Annual Water Shortage Assessment Report to DWR that is consistent with CWC requirements. The Guidance provides recommendations and suggested actions but its use is optional; suppliers may use an alternative method to perform an Annual Assessment that meets the requirements of the CWC.

DWR is responsible for developing and maintaining the electronic submittal tool, WUEdata Portal.

DWR is responsible for reviewing the submitted Annual Shortage Reports and preparing an annual summary report to the State Water Resources Control Board (State Water Board) with the results (CWC §10644 (c)(1)(B)). The DWR summary report is due on or before September 30, 2022, and every year after. The DWR report will include water shortage information at the supplier level, as well as regional and statewide analysis of water conditions. The report will also include information on Response Actions taken by Suppliers because of their Annual Assessments.

The supplier’s role is to conduct their Annual Assessment and submit an Annual Shortage Report to DWR so that it is consistent with CWC requirements. These exercises support the suppliers’ short-term resource planning to ensure that adequate water supplies are available to meet existing and near-term water needs. 

The supplier’s submitted Annual Shortage Report is developed based on the assumption that the upcoming year is going to be dry (as required by the legislation). However, implementation of any Response Actions will need to take into consideration actual water supply and demand conditions throughout the current year.

After submittal of the Annual Shortage Report, suppliers will need to perform ongoing reassessments of their water supply and demand conditions throughout the year. Suppliers will activate their Response Actions that are appropriate to their actual shortage conditions. Though a supplier’s WSCP includes predetermined procedures and actions in response to a shortage, CWC doesn’t prevent the supplier from undertaking reasonable alternative actions if needed even without formally amending the WSCP (CWC Section 10632.2). CWC calls for periodic reviews of WSCPs and adoption of any resulting amendments (CWC Section 10640(b)).