Stormwater Management Plan

Under the federal Clean Water Act (CWA) and Oregon Revised Statute 468B.050, the Oregon Department of Environmental Quality (DEQ) has issued the City of Wilsonville a renewed National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Phase I Permit, effective October 1, 2021.  

The city’s Stormwater Management Program Document (SWMP) serves as a proxy for the NPDES MS4 permit, describing activities related to the implementation of permit requirements. The SWMP contains best management practices (BMPs), which outline the specific tasks that the city will conduct to prevent and reduce stormwater pollution to the maximum extent practicable (MEP) to protect water quality and satisfy the requirements of the NPDES MS4 Permit and the CWA. 

This city’s latest SWMP was developed based on a review and evaluation of the existing stormwater management program. The SWMP document considers available technologies and practices; review of SWMP measurable goals and tracking measures; and evaluation of city resources available to implement programs.