Note: Important Dates
The 2020 SWMM may still be used until June 1, 2025, three months after the 2025 SWMM effective date. At that time, the requirements of the 2025 SWMM will apply.
2020 Stormwater Management Manual
Please note:
- Land use reviews will be conducted under the manual in place at the time of submittal of a complete application.
- Building permits will be reviewed based on the permit “in date.”
- Public Works Projects will be reviewed based on the date the Concept Development Submittal is accepted for review.
- Capital Improvement Projects and Interagency Projects will be reviewed based on 60% plan submittal date.
What is the Stormwater Management Manual?
The SWMM provides policy and design requirements that govern stormwater management. All development, redevelopment, and improvement projects within Portland on private and public property and in the public right-of-way must meet SWMM requirements. The Bureau of Environmental Services regularly revises the SWMM to meet current regulatory requirements and to provide current technical standards. Portland City Code 17.38 authorizes the SWMM.
2025 Stormwater Management Manual
The complete manual is available for download:
Review a summary of changes:
Design Details and CAD Support Files
Design details and CAD support are provided for the construction of stormwater management facilities as specified by the 2025 SWMM. For ecoroof and filter strip details, consult the 100 series.
Design Details and CAD Support Files
Forms
Vegetation and Soils
Stormwater Facility Blended Soil Vendor and Hauling List
Presumptive Approach Calculator
The Presumptive Approach Calculator (PAC) allows design professionals to enter catchment area characteristics and facility details for planters, basins, and green streets. The PAC analyzes the information and determines whether a design meets the water quality, infiltration, and/or flow control requirements of the selected hierarchy level. The PAC creates a report of project information and PAC analysis in PDF format.
2025 Presumptive Approach Calculator
Manufactured Stormwater Treatment Technologies
Environmental Services maintains a list of approved Manufactured Stormwater Treatment Technologies (MSTTs). These MSTTs have been reviewed and approved to meet the water quality treatment standards of the current SWMM when properly maintained. Projects proposing to use an MSTT must select devices from the list in Chapter 6 of the 2025 SWMM and meet Environmental Services' conditions of use, including the sizing requirements.
Approved Technologies – Conditions of Approval
Training
Environmental Services will provide online training for the 2025 SWMM. Please use the Zoom links to register for the trainings. After the trainings, a recording of each training will also be made available and posted here.
General Training:This training will provide an overview and summary of changes to the SWMM in the 2025 edition. It is designed for people who are already familiar with the material.
- Wednesday, March 12, from 12 to 1:30 pm - Zoom Registration Link
- Tuesday, April 1, from 3 to 4:30 pm - Zoom Registration Link
Presumptive Approach Calculator (PAC) Training: This training will cover changes to the PAC to implement the new 2025 SWMM requirements.
- Dates coming soon