Managing stormwater from state highways

Learn about how we manage stormwater runoff from paved surfaces like highways, rest areas, park-and-ride lots, ferry terminals and maintenance facilities in urban areas throughout the state.

In spring 2019, the Washington State Department of Ecology issued us a Municipal Stormwater Permit that regulates stormwater runoff from these paved surfaces. We want to hear from you!

We invite you to provide feedback on the 2021 Stormwater Management Program Plan (SWMPP) (PDF 523KB). The 2021 SWMPP describes how we will implement the 2019 permit’s requirements.

Send feedback to the Stormwater Permit Program

We will consider all comments received by October 1, 2022, before finalizing the 2022 plan.

Visit the Water resources and erosion control webpage for more information on stormwater policies, procedures and reports.

Traffic fatality crashes on Washington public roadways

increased 56% in March 2021 compared to March 2020.

11,906 incidents responded to

by WSDOT’s incident Response teams during the third quarter of 2021, nearly 6% more than same quarter in 2020.

WSF ridership was nearly 5.7 million in the first quarter of fiscal year 2022,

which was 1.6 million (38.3%) higher than the corresponding quarter in FY2021