Guidance on 2020 SWMM Requirements for Projects in the Public Right-of-way

This guidance can help applicants and designers understand how the City's Stormwater Management Manual requirements apply to construction projects in the public right-of-way.

The City's Stormwater Management Manual (SWMM) requires stormwater management if a project:

  • Changes an existing stormwater discharge location; or
  • Adds or redevelops more than 500 square feet of impervious area. Note, existing or proposed trees in the right-of-way can reduce the amount of area requiring stormwater management.
    Note, projects reviewed through a PBOT Minor Improvements Permit will not be reviewed for SWMM conformance.

Find more information about how to determine when a right-of-way project triggers the SWMM.

If stormwater management is required for public improvements, there are four potential options to meet SWMM requirements:

  1. Discharge to existing facilities.
  2. Construct new stormwater facilities.
  3. Apply tree credits.
  4. Pay an Offsite Stormwater Management Fee through Special Circumstances.

Find more information about how to meet SWMM requirements for projects in the right-of-way.

This guidance provides a simplified explanation of SWMM requirements and additional diagrams to assist applicants with understanding how to implement the SWMM. However, always consult the SWMM for complete requirements.


Systems Development

Environmental Services
phone number503-823-7761Questions about sewer connections, stormwater management, and drainage reserves at the land use or building permit stage.