NPDES MS4 Phase I Permit - Clackamas Group

Oregon City's Stormwater Discharge Permit was reissued on September 15, 2021 and took effect on October 1, 2021. Oregon City is one of 12 co-permittees that comprise the Clackamas County Group. View the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Phase I Permit - Clackamas Group (PDF).

Oregon City's Stormwater Management Plan (SWMP) was updated and submitted to DEQ for review on November 30, 2022. View the 2022 SWMP NPDES Phase I Stormwater Management Program Document (PDF).

The Stormwater Management Plan (SWMP) implementation requires numerous:

• Codes
• Ordinances
• Policies
• Procedures
• Guidance manuals
• Checklists
• Forms
• Mapping
• Other related documents

Throughout the City's current SWMP, the relevant documents are noted within each program category or best management plan (BMP). The referenced documents have been compiled into the SWMP Document Library.

Department of Environmental Quality

The OR Department of Environmental Quality (DEQ) regulates stormwater runoff from the City of Oregon City through the NPDES MS4 Discharge Permit, issued to Clackamas County and its co-permittees:

• City of Oregon City
• City of Lake Oswego
• City of Gladstone
• City of West Linn
• City of Milwaukie
• City of Wilsonville
• City of Happy Valley
• City of Johnson City
• City of Rivergrove
• Oak Lodge Water Service District
• Clackamas County
• Water Environment Services

Additionally, DEQ has set Total Maximum Daily Loads (TMDL) for water bodies located in the Willamette River Basin. Currently there are 3 parameters of concern: temperature, bacteria, and mercury. A TMDL Implementation Plan is required to address these parameters. Oregon City's SWMP serves as the implementation plan for bacteria and mercury, and our TMDL Implementation Plan addresses temperature.

Each co-permittee is required to submit an annual report to DEQ summarizing accomplishments and implementation of the individual SWMP. TMDL Implementation Plan activities are reported in an annual TMDL Progress Report.

Please visit the NPDES Annual Reports page to view these Reports.