Updating Stormwater Regulations - What & Why

What’s Happening Now?

Our proposed 2021 Stormwater Code and Manual update is scheduled to be effective in July 2021. Our new rules will replace the current Stormwater code and Directors' Rules, which are administered jointly by SDCI and Seattle Public Utilities (SPU). For more information, visit our background page.

The first draft documents of the 2021 Stormwater Code and Manual, supporting documentation, and other related project code changes were shared in April 2020 for public comment. They are still available for your review on the Project Documents pagebut have not been updated yet. SPU and SDCI are busy responding to Ecology comments, public comments, and internal comments.

Revised draft documents will be posted during the two upcoming public review periods as follows:

  • November 2 through November 20, 2020: The revised draft Stormwater Code, Volume 1 of the Manual, and Appendix B (Additional Submittal Requirements) will be posted for public review.
  • January 11 through February 19, 2021: The full revised draft of the Stormwater Manual (all Volumes and Appendices) will be posted for public review.

As part of this process, we will be holding public meetings during three separate timeframes:

  • Spring of 2020 (Completed)Prior to submittal of the Draft Stormwater Code and Manual to Ecology(Two2 online public meetings were held on: April 26 and May 6, 2020. If you missed them, watch our recording of the April 26 meeting and take a look at the PowerPoint!
  • November 12, 2020 (Completed): This meeting focused on changes to the Stormwater Code, Volume 1 of the Stormwater Manual, Appendix B (Additional Submittal Requirements) and Appendix I (Landscape Management Plan and Integrated Pest Management). If you missed this meeting, watch the recording and take a look at the PowerPoint. Please note: the graphs of the Peak Flow Control Standard changes on pages 37 and 38 were incorrect in the meeting presentation and are corrected in the files posted here.
  • January 28, 2021: This meeting will focus on changes to the full revised draft of the Stormwater Manual (all volumes and appendices) since the spring 2020 public review period.
  • Spring 2021: City Council Public Meeting

Project Benefits

Our stormwater code protects people, property, and the environment by controlling how rain that beomes stormwater runsoff flows off of streets, buildings, and parking lots. Stormwater runoff can cause flooding, landslides, and erosion that can damage our homes, businesses, and property. Stormwater runoff carries oil and grease, fertilizers, pesticides and other toxic chemicals to our creeks, lakes, bays, rivers, and other waterways.

The End Result

Our regulations will be equivalent to Ecology's 2019 Stormwater Manual and address concerns and topics identified by internal and external stakeholders.