Washington Department of Transportation Municipal Stormwater Permit

This permit applies to the Washington State Department of Transportation (WSDOT). It requires WSDOT to manage polluted stormwater runoff from its properties to keep pollution out of nearby streams, rivers, and other waterways.

The permit covers state highways and transportation facilities, as well as rest stops, park and ride lots, ferry terminals, and maintenance facilities located in urban parts of Washington.

The current permit has been in effect since April 5, 2019, and will continue until a new permit is issued.

Why does WSDOT need to control stormwater?

WSDOT manages more than 7,000 miles of highway across Washington. When you add rest stops, ferry terminal parking lots, and park and ride lots, that's over 40,000 acres of pavement. Unlike natural ground, pavement does not let water soak in. Instead of being naturally filtered before reaching streams or groundwater, stormwater runs off these surfaces and can carry pollution into nearby waterways.

Current permit and related documents

2019 WSDOT Municipal Stormwater General Permit, effective April 5, 2019
Fact sheet for the draft 2019 general permit with Response to Comments
Application for Coverage (Notice of Intent)
WSDOT Highway Runoff Manual
Implementing agreement between Ecology and Transportation regarding application of the Highway Runoff Manual (2024)

Permit reissuance

The draft permit is now available for review and public comment. We invite comments on the draft general permit beginning at 9 a.m. on July 1 through 11:59 p.m. on Aug. 21, 2026. A formal announcement was published in the Washington State Register.

After the public comment period closes, we will review all comments and make appropriate revisions. We will publish an official Response to Comments as an appendix to the fact sheet and make a final decision on permit issuance, we expect a decision by the end of 2026.

Public involvement

We will accept comments on the draft permit from 9 a.m. July 1 through 11:59 p.m. Aug. 21, 2026. If your feedback is about a specific part of the current permit language, please note the section and page number in your comments.

Ways to comment

Provide comments online (preferred)
Submit by U.S. mail:
Foroozan Labib
Washington State Department of Ecology Water Quality Program
P.O. Box 47696
Olympia, WA 98504-7696
Provide testimony at our public hearing.

Public meeting and hearing

We will host an online public meeting, using Zoom, in August. We will share a presentation about the permit reissuance process and our proposed changes in the draft permit. A question-and-answer session will follow, then a formal public hearing. The hearing provides opportunity for the public to give formal spoken testimony on the proposed draft permit. The public hearing begins immediately following the meeting and concludes when public testimony is complete. Spoken testimony will receive the same consideration as written comments.

Online Public Meeting & Hearing
Aug. 5, 2026 – 1:30 p.m.
Register in advance for this meeting.
After registering, you will receive a confirmation email containing information about joining the meeting.

Anticipated timeline

July 1 through Aug. 21, 2026: Formal public comment period on the draft permit
Aug. 5, 2026: Online public meeting and hearing
Fall 2026: Develop final permit language and write the Response to Comments
End of 2026: Decision on reissuance

Permit compliance

Visit WSDOT's Managing stormwater from state highways webpage for information on:

Which areas the permit covers
WSDOT's stormwater management program
Annual reports
Monitoring reports
Total Maximum Daily Load (TMDL) implementation reports

Previous permit documents

WSDOT Municipal Stormwater General Permit (effective April 5, 2014 — April 4, 2019)
Errata
Fact sheet for the draft 2014 general permit

Contact information

Foroozan Labib
WSDOT Permit Lead
foroozan.labib@ecy.wa.gov
564-669-4292