Drought is a recurring feature of California’s climate.
In 2018, the California Legislature enacted into law new requirements for urban water suppliers to increase drought resilience and to improve communication of water shortage response actions. Each urban water supplier is required to prepare an Annual Water Supply and Demand Assessment (Annual Assessment) and submit an Annual Water Shortage Assessment Report (Annual Shortage Report) to DWR on or before July 1, 2022, and every year thereafter.
Annual Shortage Reports must be submitted to DWR as follows:
Suppliers are responsible for providing a reliable supply of water for their customers, evaluating their water supply status on a regular basis and, in the case of anticipated water shortages, preparing mitigation actions.
The results of these evaluations are included in the following suppliers’ plans and reports:
The requirements for Annual Assessments and the resulting Annual Shortage Reports are found in Section 10632 of California Water Code (CWC). Every Supplier that either provides over 3,000 acre-feet of water annually or serves more than 3,000 urban connections is required to perform an Annual Assessment and submit an Annual Shortage Report to DWR every year beginning July 1, 2022. A supplier that relies on imported water from the State Water Project or the Bureau of Reclamation shall submit its annual water supply and demand assessment within 14 days of receiving its final allocations, or by July 1 of each year, whichever is later.
The Annual Shortage Report includes information on anticipated shortage, triggered shortage response actions, compliance and enforcement actions, and communication actions as described in each Supplier’s WSCP.
Suppliers’ assessments and reports are important for drought response as these exercises help proactively prepare for anticipated water shortages in the coming year. The tools a supplier selects to mitigate shortages are called Response Actions and are ideally locally appropriate and effective. The Response Actions can focus on increasing supply in the near term or reducing demand temporarily, making operational changes, implementing water use prohibitions, imposing emergency rates, rationing, and other methods.
Annual Water Supply and Demand Assessments Summary Report
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 reports to the State Water Board are due on or before September 30th every year, starting in the year 2022. Each of DWR summary reports will include information on anticipated water shortages at the supplier level, as well as regional and statewide analysis of water conditions. The reports 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)).