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MS4 Permit Library
The MS4 Permit requires the posting of guiding documents:
- The current MS4 Permit is posted here.
- The 2026 Stormwater Management Program (SWMP) PUBLIC REVIEW DRAFT is posted here.
Best Management Program documents include:
- Annual Reporting
- Construction Site Runoff Control
- Hydromodification Assessments
- Illicit Discharge Detection and Elimination
- Industrial and Commercial Facilities' Regulation
- Pollution Prevention and Good Housekeeping for Municipal Operations
- Post-Construction Site Runoff
- Public Education and Outreach
- Public Involvement and Participation
- Stormwater Management Program Document (SWMP)
- Stormwater Retrofit Strategies
- Total Maximim Daily Load (TMDL) Implementation Planning and Reporting
- Water Quality Monitoring and Reporting
Library documents by year:
Erosion Prevention and Planning and Design Manual.pdf2026 Stormwater Management Program (SWMP) PUBLIC REVIEW DRAFT2025 Clackamas County Biomonitoring Assessment2025 MS4 Permit Annual Report2023 Hydromodification and Retrofit Strategy Update2023 Illicit Discharge Detection and Elimination Standard Operating Procedure2023 Industrial/Commercial Stormwater Inspection Program2022 Erosion Control Draft Checklist2022 Surfacewater Draft Checklist2022 Clackamas County Comprehensive Stormwater Monitoring Plan2022 OLWS SWMP UPDATED for FY242022 Public Outreach, Education and Involvement Framework2022 Vegetated Stormwater Facility Inspection SOP2021 Zone Cleaning Map2020 Erosion Prevention Manual2015 Hydromodification Report2015 Stormwater Retrofit Strategy2014 Living with the American Beaver2013 Macroinvertebrate Assessment2013 Stormwater Implementation Guide1991 Stormwater Facilities Handbook
