What is the Stormwater Management Plan?
The Stormwater Management Plan (SWMP) is the City’s comprehensive plan to prevent harmful pollution from entering Portland’s rivers and streams. The plan is a requirement of the City’s Municipal Separate Storm Sewer System Permit, also known as an MS4 permit or National Pollutant Discharge Elimination System (NPDES) permit. Environmental Services leads the administration of and compliance with the City’s MS4 permit, including the SWMP and Monitoring Plan, but multiple City bureaus are responsible for implementing the requirements.
The City of Portland and Port of Portland both operate storm sewer systems within Portland’s urban services boundary. The two jurisdictions, or co-permittees, hold a joint MS4 permit issued by the Oregon Department of Environmental Quality (DEQ) in accordance with federal Clean Water Act regulations.
Why is the Stomwater Management Plan important?
When it rains, stormwater washes over roofs, streets, and other hard surfaces. Stormwater can carry oil, pesticides, metals, chemicals, dirt, and other pollutants into storm sewers, which discharge into our local rivers and streams. Roughly 20% of the area in Portland’s urban services boundary discharges stormwater through the City’s MS4.
To prevent this harmful pollution, the SWMP describes how the City will reduce the discharge of pollutants from its storm sewer system and addresses these program areas:
- Public Education and Outreach
- Public Involvement and Participation
- Illicit Discharge Detection and Elimination
- Construction Site Runoff
- Post-Construction Site Runoff for New and Re-Development
- Pollution Prevention and Good Housekeeping for Municipal Operations
- Industrial and Commercial Facilities
Why is the Stormwater Management Plan changing?
The updated SWMP reflects new knowledge and insights about environmental management practices, emerging pollution risks, and pollution prevention strategies. It presents detailed stormwater program measures with up-to-date goals and milestones and a way to adapt to shifting community priorities and water quality developments quickly.
What is the Monitoring Plan?
The Monitoring Plan describes the City’s monitoring objectives, strategy, and procedures for collecting and analyzing stormwater and surface water samples. The Monitoring Plan is also a requirement of the City’s MS4 permit.
Why is the Monitoring Plan changing?
Due to new MS4 permit requirements, the City updated the previous Monitoring plan. The new Monitoring Plan strategy includes both new and existing monitoring locations, sampling frequencies, updated pollutant parameters, analytical methods, quality control procedures, staffing resources, and a summary of field operating procedures.
Comment period is closed
The City accepted public comments on the draft Stormwater Management Plan and Monitoring Plan from Sep. 1 through Sep. 30, 2022. The comment period closed on Sep. 30 at 5:00 p.m.