Urban Water Use Efficiency Standards, Variances and Performance Measures

The 2018 Legislation (Senate Bill 606 and Assembly Bill 1668) establishes a new framework for long-term improvements in urban water use efficiency and drought planning as California adapts to climate change impacts.

The legislation requires that long-term urban water use efficiency standards be set so that urban retail water suppliers’ urban water use objectives (UWUO; defined below), together with other water uses excluded from the long-term standards, would exceed the statewide 2020 water conservation targets required pursuant to SB X7-7 (California Water Code (WC) §10609.2(d)). (Water uses excluded from the standards include commercial, industrial, and institutional (CII) indoor water use and CII outdoor landscape irrigation water use not connected to a dedicated irrigation meter. These water uses are subject to CII water use performance measures.)

Legislative Requirements

The 2018 Legislation requires DWR, in coordination with the State Water Board, to perform the necessary studies and investigations on the following:

  • The indoor residential water use and potential benefits and impacts associated with a changing standard and may jointly recommend to the Legislature an indoor residential water use standard that more appropriately reflects best practices (WC §10609.4(a))


The 2018 Legislation also requires DWR, in coordination with the State Water Board, conduct necessary studies and investigations and develop the following recommendations for adoption by the State Water Board:

  • Standard for outdoor residential water use (WC §10609.6).
  • Standard for CII outdoor irrigation of landscape areas with dedicated irrigation meters or equivalent technologies (WC §10609.8).
  • Appropriate variances for unique uses that have a significant effect on urban retail water supplier’s UWUO (WC §10609.14).
  • Guidelines and methodologies for calculating the UWUO (WC §10609.16).
  • Performance measures for CII water use (WC §10609.10).

The State Water Board, in coordination with DWR, is required to adopt long-term standards, appropriate variances, guidelines, and methodologies for calculating UWUO by June 30, 2022 (WC §10609.2). These standards, variances, and performance measures will become effective following the State Water Board’s adoption of the recommendations through a public rulemaking process.

DWR Reports to the Legislature

Per the 2018 Legislation, DWR has prepared and transmitted the following reports to the Legislature for further consideration:

DWR Recommendations to the State Water Board

On September 29, 2022, DWR provided recommendations developed in response to the 2018 Legislation to the State Water Board in a memorandum that also summarizes the background and robust public process to support the development of these recommendations.

Full reports detailing DWR methods, technical analyses, studies, public input, and recommendations were completed in September 2022, and transmitted to the State Water Board on October 28, 2022.

To streamline document development, DWR organized the various reports into an Urban Water Use Efficiency Recommendation Package (Recommendation Package) that allows mutual referencing and incorporates content by reference. All reports in this Recommendation Package are given a serial number (e.g., WUES-DWR-2021-xx). For each report, Appendix A includes the list of documents within the Recommendation Package that are incorporated by reference.  A complete list of the reports in the Recommendation Package is included in a PDF here for reference. Links to the reports in the Recommendation Package are posted below.

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Public Notices

The Drought Resilience Interagency & Partners (DRIP) Collaborative will hold an informational meeting for DRIP Collaborative member-volunteers for the recently formed workgroups based on the following focus areas; Drought-Relevant Data, Drought Preparedness for Domestic Wells, and Drought Definition and Narrative.


DWR has proposed amendments to California Plumbing Code (CPC) sections dealing with plumbing design standards for recycled water. A 45-day comment period ending July 1, 2024 is the public’s chance to review and provide feedback to DWR on these proposed changes. The CPC supports local building and planning departments, as well as potable and recycle ...