Eastern Washington Phase II Municipal Stormwater Permit
We develop and administer Clean Water Act National Pollutant Discharge Elimination System (NPDES) municipal stormwater permits in Washington. The Eastern Washington Phase II permit requires local governments to manage and control stormwater runoff so that it does not pollute downstream waters.
The Eastern Washington Phase II Municipal Stormwater Permit covers 19 cities and portions of six counties. Find a list of cities and counties covered by this permit.
The current permit is effective Aug. 1, 2019, and expires July 31, 2024.
Overview of permit timelines
Permit timelines for new, continuing, and secondary permittees will be available in the coming weeks. These timelines will provide an overview of major deadlines for implementing permit requirements.
Annual reports for the calendar year are due by March 31 the following year.
Municipal stormwater permit guidance
For guidance about applying, changing, or implementing and complying with your municipal stormwater permit see municipal stormwater guidance. Stormwater manuals provide stormwater permit implementation and management guidance.
For more general stormwater permit guidance, see the stormwater guidance page.
Frequently asked questions
Have a question? Check out our frequently asked questions page