Urban Water Loss

Drought and other water shortage issues highlight the need to manage water loss in water distribution systems. Water loss can result from seepage, leaks, and pipe failures due to aging infrastructure and/or errors in data, and water theft. Water utilities can increase water supplies and recover revenue by identifying the scale and cost of these losses.


Wholesale Water Suppliers


Senate Bill (SB) 606 adopted in 2018 required DWR to submit to the Legislature a final report with recommendations on the feasibility of developing and enacting water loss reporting requirements for urban wholesale water suppliers. This report was submitted in May 2020. An urban wholesale water supplier provides more than 3,000 acre feet of water annually at wholesale for potable municipal purposes. According to the report, California is home to 49 urban wholesale water retailers. In developing this report, DWR coordinated with the State Water Resources Control Board (Board) and solicited public input through three interested party meetings/webinars, interviewed multiple urban wholesale water suppliers and discussed issues with many industry and academic water loss and water meter experts.

Urban Retail Water Suppliers


SB 555 (Wolk) adopted in 2015 during the drought, required urban retail water suppliers to submit water loss audits to the state by October 1, each year. The reporting deadline was subsequently modified by AB 1414 (Friedman, Statute of 2019), which required fiscal year reporters to submit their report by January 1 of each year starting January 1, 2021. AB 1414 changes the reporting deadline for all urban water suppliers (whether reporting on a calendar year basis or fiscal year basis), to submit on or before January 1 of each year starting January 1, 2024. Submitted water loss audits shall be system-specific and in the case of an urban retail water supplier with two or more separate public potable water systems, the urban retail water supplier shall submit a separate report for each potable water system (CCR § 638.5).


Urban retail water suppliers are those that either serve more than 3,000 connections or that produce more than 3,000 acre feet of water each year. Through requirements set forth in the CWC, DWR was required to establish regulations for conducting and validating water loss audits, technical qualifications for persons performing water loss audit validation, and reporting requirements for submitting validated water loss audits to DWR. Once audits are validated by validators certified by AWWA, the urban retail water supplier is required to submit it them to DWR.


Water audit reporting for Calendar Year 2021 or Fiscal Year 2021/2022 earlier:

You can still use the WUEdata portal to submit the AWWA Free Water Audit Software (FWAS) v5.0 and required DWR pdf format certification documents. Water Systems may choose to submit or resubmit v5.0 or v6.0 documents for previous years. 

Water audit reporting for Calendar Year 2022 or Fiscal Year 2022/2023 (due January 1, 2024) and subsequent years:

You must submit FWAS v6.0 and associated Excel certification templates (templates available here). Only v6.0 format will be accepted for reporting on future years. 


Water Loss Audit Reporting Program


DWR encourages water agencies to detect and resolve leaks when economically feasible. The Water Loss Audit Reporting Program provides guidance on how water agencies can identify and eliminate water loss in water distribution systems. The audit uses local water agency data over a defined period to identity water losses. Once an agency has determined the water losses and performed a benefit-cost analysis to verify economic feasibility of addressing losses, a leak detection program may be established. The leak detection program, which is implemented in the field, requires knowledge of the distribution system layout and proficiency in using sonic equipment to identify areas with leaks. The American Water Works Association manual M36: Water Audits and Loss Control Programs Guidebook provides information on what steps are required to establish and perform a leak detection program, as well as more information on retailer water audits.


Leak Detection


DWR Regional Offices can provide water agencies with leak detection equipment for a short-term loan. DWR representatives can provide assistance to local water agencies seeking to conduct a water audit and leak detection surveys for their water distribution systems.


To be placed on a list of parties interested in water system losses, sign up for water loss communication at this link: https://tinyurl.com/WaterLossCommunication


For more information on public process records, or for webinars on water loss and leak detection topics, please contact DWR WUE Water Loss Program at WaterLoss@water.ca.gov.


The California-Nevada (CA-NV AWWA) Section of the American Water Works Association (Section) is a leading organization in California to combat water loss in California. The Section led the California Water Loss Control Collaborative which included utility personnel, industry organizations, non-profits as well as state entities, culminating in the validation of the majority of water loss audits submitted in 2016. In addition to that effort, the Section is establishing the Water Audit Validator (WAV) Certification Program.

Interested in becoming a California Water Audit Validator? View a full schedule of upcoming Water Audit Validation Certificate Courses provided by the CA-NV AWWA.



sheared hydrant, water loss, showerDWR’s Water Loss Audit Reporting Program proactively promotes practices to minimize water loss from water distribution failures. Courtesy of Natalie Pavlovski/DWR                                                                                      












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