Updating Stormwater Regulations - Project Documents

Project Documents

• Current 2016 Stormwater Code and Stormwater Manual

Final SPU Public Drainage System Requirements Director's Rule DWW-210 (effective July 1, 2021)

The new SPU Public Drainage System Requirements Director's Rule (SPU DWW-210) includes Storm Mainline Extension, Approved Point of Discharge, and Ensuring Sufficient Capacity Requirements as well as the Public Drainage System Design Requirements that were in SPU CAM 1180. This rule replaces SDCI's Small Project Point of Discharge protocol and will prohibit any new drainage discharges to the "formerly combined" public sanitary sewers and require mainline extensions for certain projects in the combined sewer and ditch and culvert areas.

• SPU Public Drainage System Requirements Director's Rule

Final 2021 Seattle Stormwater Code and Manual (effective July 1, 2021)

• Summary of Changes
  • Summary of Changes to the Stormwater Code
  • Summary of Changes to the Stormwater Manual
• Stormwater Code (Seattle Municipal Code)
  • 2021 Stormwater Code (Clean Version of full SW Code)
  • 2021 Stormwater Code Ordinance, Council Bill 120044
• 2021 Stormwater Manual (Joint Director's Rule SPU DWW-200/SDCI 10-2021)
  • Full Seattle Stormwater Manual - (Clean version including all Volumes and Appendices)
• The following are the individual Volumes and Appendices from the 2021 Seattle Stormwater Manual with Track-Changes:
  
  • Volume 1 - Project Minimum Requirements
  • Volume 2 - Construction Stormwater Control
  • Volume 3 - Project Stormwater Control
  • Volume 4 - Source Control
  • Volume 5 - Enforcement
  • Appendix A - Definitions
  • Appendix B - Additional Submittal Requirements
  • Appendix C - On-site Stormwater Management BMP Infeasibility Criteria
  • Appendix D - Subsurface Characterization and Infiltration Testing for Infiltration BMPs
  • Appendix E - Additional Design Requirements and Plant Lists
  • Appendix F - Hydrologic Analysis and Design
  • Appendix G - Stormwater Control Operations and Maintenance Requirements
  • Appendix H - Financial Infeasibility Documentation for Vegetated Roofs and Rainwater Harvesting
  • Appendix I - Landscape Management Plans and Integrated Pest Management Plan

May 3, 20201 - Final Draft of Code Changes Submitted to City Council

• Draft Stormwater Code Ordinance (Revised Sections Only)

See below for the most current draft of the Stormwater Manual and SPU Public Drainage System Director's Rule.

Draft Documents for Notice of Rulemaking - March 23 through April 9, 2021

• Summary of Changes
  • Summary of Changes to the Stormwater Code
  • Summary of Changes to the Stormwater Manual
• Stormwater Code (Seattle Municipal Code)
  • Draft Stormwater Code Ordinance (Revised Sections Only)
• Draft of new SPU Public Drainage System Director's Rule (SPU DWW-210): This new rule includes Storm Mainline Extension, Approved Point of Discharge, and ensuring sufficient capacity requirements as well as the Public Drainage System Design Requirements that were in SPU CAM 1180. This rule will replace SDCI's Small Project Point of Discharge protocol and will prohibit any new drainage discharges to the "formerly combined" public sanitary sewers and require mainline extensions for certain projects in the combined sewer and ditch and culvert areas.
  • Draft SPU Public Drainage System Director's Rule (Clean Version)
  • Draft SPU Public Drainage System Director's Rule (Version w/ redlined changes from last public review period)
• Draft 2021 Stormwater Manual (Joint Director's Rule SPU DWW-200/SDCI 10-2021)
  • Volume 1- Project Minimum Requirements
  • Volume 2- Construction Stormwater Control
  • Volume 3- Project Stormwater Control
  • Volume 4- Source Control
  • Volume 5- Enforcement (no change at this time)
  • Appendix A- Definitions
  • Appendix B- Additional Submittal Requirements
  • Appendix C- On-site Stormwater Management BMP Infeasibility Criteria
  • Appendix D- Subsurface Characterization and Infiltration Testing for Infiltration BMPs
  • Appendix E- Additional Design Requirements and Plant Lists
  • Appendix F- Hydrologic Analysis and Design
  • Appendix G- Stormwater Control Operations and Maintenance Requirements
  • Appendix H- Financial Infeasibility Documentation for Vegetated Roofs and Rainwater Harvesting
  • Appendix I- Landscape Management Plans and Integrated Pest Management Plan

If you wish to submit a comment, please complete the comment template and email it to SPUStormwaterCodeRev@seattle.gov or mail your comments to:

Sherell Ehlers
Seattle Public Utilities
700 Fifth Ave, Suite 4400
PO Box 34018
Seattle, WA 98124-4018

Email correspondence is preferred.

Draft Documents for Public Review #3 - January 11 through February 19, 2021

• Summary of Changes
  • Summary of Changes to the Stormwater Code
  • Summary of Changes to the Stormwater Manual
    • Errata for Stormwater Manual Posted (updated pre-sized factors and other changes not included in Stormwater Manual below)
• Draft 2021 Stormwater Code
  • Seattle Municipal Code (Chapters 22.800 - 22.808)
• Related Code and Director's Rules
  • New Draft SPU Public Drainage System Director's Rule (This new rule includes Storm Mainline Extension and Approved Point of Discharge rules as well as the Public Drainage System Design Requirements that are currently in SPU CAM 1180. This rule will replace SDCI's Small Project Point of Discharge protocol and will prohibit any new drainage discharges to the "formerly combined" public sanitary sewers.) New Draft Grading Code Revisions (SMC Subtitle IB Chapter 22.170)
  • New Draft Grading Code Revisions (SMC Subtitle IB Chapter 22.170)
  • New Draft Land Use Code Revisions
• Draft 2021 Stormwater Manual (Joint SPU/SDCI Director's Rule)
  • Volume 1- Project Minimum Requirements
  • Volume 2- Construction Stormwater Control
  • Volume 3- Project Stormwater Control
  • Volume 4- Source Control
  • Volume 5- Enforcement (no change at this time)
  • Appendix A- Definitions (no change at this time)
  • Appendix B- Additional Submittal Requirements
  • Appendix C- On-site Stormwater Management BMP Infeasibility Criteria
  • Appendix D- Subsurface Characterization and Infiltration Testing for Infiltration BMPs
  • Appendix E- Additional Design Requirements and Plant Lists
  • Appendix F- Hydrologic Analysis and Design
  • Appendix G- Stormwater Control Operations and Maintenance Requirements
  • Appendix H- Financial Infeasibility Documentation for Vegetated Roofs and Rainwater Harvesting
  • Appendix I- Landscape Management Plans and Integrated Pest Management Plan

If you wish to submit a comment, please complete the comment template and email it to SPUStormwaterCodeRev@seattle.gov or mail your comments to:

Sherell Ehlers
Seattle Public Utilities
700 Fifth Ave, Suite 4400
PO Box 34018
Seattle, WA 98124-4018

Email correspondence is preferred.

Note: The actual Stormwater Code and Manual changes are still to be determined. However, our regulations must be equivalent to Ecology's NPDES 2019 Stormwater Permit (Ecology Permit).

SEPA Determination of Non-Significance December 10-24, 2020

We have conducted a State Environmental Protection Act (SEPA) environmental review of the City of Seattle's proposed 2021 Stormwater Code and Rule Update. The lead agency, Seattle Public Utilities (SPU), has issued a Determination of Non-Significance (DNS). This proposal involves the adoption of ordinances amending the City of Seattle's Stormwater Code and associated Directors' Rule. 

• SEPA Environmental Checklist for the City of Seattle 2021 Stormwater Code and Rule Update
• Determination of Non-Significance (DNS)

You can see all of the documents related to the SEPA review and DNS listed under the headings below.

Draft Documents for Public Review #2 - November 2 - November 20, 2020

• Summary of Changes
  • Summary of Changes to the Stormwater Code
  • Summary of Changes to the Stormwater Manual (Volume 1 and Appendices B and I only)
• Draft Stormwater Code
  • Seattle Municipal Code(Chapters 22.800 - 22.808)
• Draft Stormwater Manual (Joint SPU/SDCI Director's Rule)
  • Volume 1 - Project Minimum Requirements
  • Appendix B - Additional Submittal Requirements
  • Appendix I - Landscape Management Plan and Integrated Pest Management

Draft Documents for Public Review #1 - April 1 through May 16 20, 2020

These documents were posted for the review period of April 1 through May 16 2020.

• Summary of Changes
  • Summary of Changes to the Stormwater Code
  • Summary of Changes to the Stormwater Manual
• Draft Stormwater Code
  • Seattle Municipal Code(Chapters 22.800 - 22.808)
• Draft Stormwater Manual (Joint SPU/SDCI Director's Rule)
  • Volume 1 - Project Minimum Requirements
  • Volume 2 - Construction Stormwater Control
  • Volume 3 - Project Stormwater Control
  • Volume 4 - Source Control
  • Volume 5 - Enforcement (no change at this time)
  • Appendix A - Definitions (no change at this time)
  • Appendix B +- Chemical Treatment (to be retired)
  • Appendix C - On-site Stormwater Management BMP Infeasibility Criteria
  • Appendix D - Subsurface Characterization and Infiltration Testing for Infiltration BMPs
  • Appendix E - Additional Design Requirements and Plant Lists
  • Appendix F - Hydrologic Analysis and Design
  • Appendix G - Stormwater Control Operations and Maintenance Requirements
  • Appendix H - Financial Infeasibility Documentation for Vegetated Roofs and Rainwater Harvesting
  • Appendix I - Integrated Pest Management Plan
• Draft Stormwater Manual Figures
  • Manual Figure Redlines