Water is a precious, limited resource. It is also a shared resource. Drinking water for our growing population in the Pacific Northwest competes with other users that include agriculture, industry, recreation, and maintaining an adequate stream flow for fish. In 2003, the Washington State Legislature passed the Municipal Water Law (MWL), which requires municipal water suppliers to have a Water Use Efficiency (WUE) program. If you are not sure if your system is a municipal water supplier, contact your regional planner.
By working with public water systems to implement water use efficiency programs, we strive to ensure a safe and reliable supply of drinking water to meet current and future needs.
Water systems can help prevent potential health and sanitation risks to their customers by effectively planning and implementing WUE measures. This means fewer emergencies when water supplies are scarce, especially during summer months when it rains less, and user demands are high.
The WUE requirements emphasize the importance of measuring water use and evaluation the effectiveness of your WUE program. There are three fundamental elements:
- Planning requirements.
- Distribution leakage standard (10 percent).
- Goal setting and WUE reporting.
You will find WUE requirements in Chapter 246-290 WAC and in the May 2025 revised fourth Edition Water Use Efficiency Guidebook 331-375 (PDF).
Use the WUE Worksheet 331-767 (Word) to help you gather the necessary data to fill out the report. You can also find helpful resources on our WUE Annual Report Help webpage.
We focus our efforts on providing technical assistance and guidance to help systems develop an affective WUE program that meets the rule requirements. Violators may face formal enforcement, including red operating permits, if their water system fails to demonstrate that they have met the WUE requirements.
Fin more information on our WUE Rule Background Information webpage.
For More Information
Use the links below to find more information.
- Rule Background Information
- Leakage and Water Loss Control
- Annual Report Help
- Goal Setting Public Forum Information
- Guidance for Small Water Systems
- Water Meters
- Publications and Resources
If you have any questions, email WUE@doh.wa.gov.