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. 

Current permit documents

Supporting documents

Overview of permit timelines

View permit timelines for new and continuing permittees. These timelines 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

Permit History

To access previous permits and learn about past permit cycle processes, such as appeals, public comments, and draft reviews, see municipal stormwater history.

Keep in touch with us

To receive email updates about this permit, join the Eastern Washington Phase II Municipal Stormwater Permit listserv.