King County Stormwater Management Program Plan

Our Stormwater Management Program (SWMP) Plan lists our proposed actions to comply with the Phase I Municipal Stormwater National Pollutant Discharge Elimination System (NPDES) Permit (Phase I Permit) issued by the Washington State Department of Ecology.

The SWMP is also attached to our Annual Report, which provides information for our previous year's work related to the Phase I Permit.

Please let us know your feedback to help shape the SWMP Plan. Comments submitted after March 31 will be considered for next year's program plan.

Download current document here:

2022 Stormwater Management Program Plan (207 MB)
2021 Stormwater Management Program Plan (1.3 MB)
2020 Stormwater Management Program Plan (1.0 MB)
2019 Stormwater Management Program Plan (14.7 MB)
2018 Stormwater Management Program Plan (14.7 MB)
2017 Stormwater Management Program Plan (12.2 MB)
2016 Stormwater Management Program Plan (11.3 MB)
2015 Stormwater Management Program Plan (14.6 MB)
2014 Stormwater Management Program Plan (7.5 MB)
2013 Stormwater Management Program Plan (22.1 MB)