WSDOT Municipal Stormwater Permit

This permit specifically covers the Washington State Department of Transportation (WSDOT). Through this permit, we require the agency to manage and control polluted stormwater runoff to protect downstream waters from pollution.

Besides covering state highways and transportation-related facilities, this permit also covers stormwater discharges from rest areas, park and ride lots, ferry terminals, and maintenance facilities within urban areas of Washington.

The current permit went into effect April 5, 2014 and expires April 5, 2019.

Why does WSDOT need to control stormwater?

Statewide, WSDOT oversees more than 7,000 miles of highway. When rest areas, ferry terminal holding lots, and park and ride lots are included, they manage over 40,000 acres of paved surfaces. Paved surfaces do not allow water to penetrate into the ground where it can be naturally filtered and treated before entering streams or underground water supplies. This lack of infiltration results in excess stormwater running off state highway facilities each year.

Current permit and related documents

Permit reissuance

The current permit expires on April 5, 2019. We plan to reissue an updated general permit in the spring of 2019.

We are pleased to announce that the draft WSDOT Municipal Stormwater general permit is available for public comment. We invite comments on the draft permit documents beginning Dec. 5, 2018 until 11:59 p.m. on Jan. 18, 2019. We will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.

Draft WSDOT Municipal Stormwater General Permit
Fact Sheet
Application for Coverage (Notice of Intent)
Draft Highway Runoff Manual
Public Notice of Draft

What's changing

We are updating the current permit language to improve consistency with the Phase I and Phase II Municipal Stormwater permits. We are also proposing the organizational change of removing the WSDOT Stormwater Management Program Plan (SWMP) from the permit. The SWMP would instead be a stand-alone document, required by the permit, that WSDOT will update annually through a public process.

How to provide comments

We will accept comments from Dec. 5, 2018 until 11:59 p.m. on Jan. 18, 2019.

You may submit comments:

Online (preferred):   Submit your comments through our online comments form.

By mail:                     Foroozan Labib
                                   Washington State Department of Ecology
                                   PO Box 47696
                                   Olympia, WA 98504-7696

In person:                  You may provide comments during our public hearing.

Workshop and hearing

We will host a workshop immediately followed by a public hearing at the following date and location:

Jan. 11, 2019 – Lacey, WA, 1:30 p.m.

During the workshop, we will explain the proposed changes to the permit and answer questions. The hearing will begin after the public workshop and will end when public testimony is complete. During the hearing, you may give oral testimony and written comments on the proposed changes. Written comments will receive the same consideration as oral testimony.

The workshop and hearing may also be attended as a webinar where individuals may view the presentation and provide testimony via computer. Register to attend via webinar.


Formal draft release for public comment: Dec. 5, 2018
Issue final permit: Spring 2019
Permit effective: Spring 2019

WSDOT permit compliance

See the WSDOT water resources and erosion control page for information on permit-related activities such as:

  • Stormwater research
  • Annual reports
  • Monitoring reports
  • Total Maximum Daily Load (TMDL) implementation reports

Previous permit documents

Permit (effective March 7, 2012)
Permit Statement of Basis