Proposed Code Amendments for Stormwater Code Are Now Available

We are updating our Stormwater Code. You can review our draft Stormwater Code Ordinance and our 2017 Proposed Stormwater Code Changes.

The proposed amendments to the Stormwater Code (Subtitle VIII of Title 22 Seattle Municipal Code) include several changes, including:

  • Modifying on-site list requirements
  • Making technical corrections
  • Clarifying submittal requirements for projects


Seattle Public Utilities (SPU) prepared an addendum to assess how these revisions affect the analyses included in the February 2015 Environmental Checklist. SPU has reviewed the findings and concluded the proposed revisions are related to the implementation and application of the updated Stormwater Code and Rule. The proposed revisions do not alter the analyses of impacts contained in the February 2015 Environmental Checklist and will not result in any significant environmental impacts.

The SEPA addendum is available for viewing at the following locations:

  • Seattle Public Utilities, General Manager/CEO’s Office Main Reception Area, Seattle Municipal Tower, Suite 4900, 700 Fifth Avenue, Seattle, Washington
  • Seattle Central Library, Public Review Documents, Level 5 Reference
  • Online at


How to Comment

Comments regarding this determination of non-significance or potential environmental impacts may be submitted through November 17, 2017. Comments may be sent to:

City of Seattle, SPU
Attn: Betty Meyer, SEPA Responsible Official
P.O. Box 34018
Seattle, WA 98124-4018

Questions or comments regarding the proposed amendments can be directed to:

Sherell Ehlers, SPU Stormwater Policy Advisor
(206) 386-4576

We anticipate making final recommendations to the Mayor by the end of the year.  Proposed legislation for City Council consideration would likely follow early next year.

Updated Stormwater Best Management Practices Address PCBs

We’ve updated Best Management Practices (BMPs) in the City of Seattle Stormwater Manual to more specifically address polychlorinated biphenyls, commonly known as PCBs, and other toxics. The updated BMPs are C1.25, C1.30, and C-1.50.  We are making this change to reflect new information that has become available on PCBs in building materials.

BMPs are tools and methods that must be used to control pollutants from construction or other ground disturbing activities so that they do not pollute stormwater.  Properly installed and maintained BMPs are the most effective tool for protecting rivers, lakes, and Puget Sound from pollution.  BMPs are required by the City of Seattle Stormwater Code and are included in permits issued by SDCI.  BMPs are inspected during permit inspections, and failure to properly implement BMPs may require corrections or a stop work order.

PCBs can be found in products such as caulk, paint, sealant, and other building materials that were used from 1940 to 1980. Some materials manufactured after 1980, such as yellow pigments in paints, have been found to contain PCBs that are inadvertently created as a byproduct of the manufacturing process.  PCBs are a hazardous material, and best management practices must be used so that PCBs do not become airborne or mix with stormwater.

Disposal of materials with PCBs is regulated by state and federal agencies.  Information on PCBs along with state and federal requirements can be found at
. For more information, contact:

Ecology Northwest Regional Office, Bellevue
(425) 649-7000

EPA Region 10, Seattle
(206) 553-6693

Join SDCI for free Stormwater Code Training Sessions

We’re offering two free training sessions to help applicants with the 2016 Stormwater Code. The focus of our training is assist you with:

  • The List Approach Calculator
  • Drainage Standard Plans
  • Infiltration Testing and Infiltration BMP’s

Please bring your questions! We’lll focus the training based on what you want to learn.

Register for one of the free trainings:

  • RSVP for Thursday, September 22 8:30-9:30 a.m.
  • RSVP for Thursday, October 13 8:30-9:30 a.m.

Trainings will take place in the Seattle Municipal Tower. 700 Fifth Avenue, Suite 4080.

Stormwater Training Flyer

Are you ready for the 2016 Stormwater Code?

The 2016 Stormwater Code became effective on January 1, 2016. The City of Seattle is offering a series of free training sessions to assist builders and designers with implementing the 2016 Stormwater Code. Be sure to register soon because classes are filling up quickly!

The training sessions will cover:

  • What’s new?
  • What’s changed?
  • The Stormwater manual
  • Infiltration Requirements
  • On-Site Stormwater Management and the Calculator
  • Question and answer session


Email to register for one of the following FREE training sessions (space is limited):

  • Wednesday, January 6
    8:00 – 9:30 a.m.
  • Thursday, January 7
    2:30 – 4:00 p.m.
  • Wednesday, January 20
    8:00 – 9:30 a.m.
  • Thursday, January 21
    2:30 – 4:00 p.m.

The 2016 Stormwater Code, the Stormwater Manual, and the associated submittal documents are now available on the Stormwater Code Page. Our new rules will replace the current Stormwater Code and Directors’ Rules, which are administered jointly by us and Seattle Public Utilities (SPU).

Which Version Applies to My Project?

If your project application is submitted on, or after, January 1, 2016, you must comply with the 2016 Stormwater Code and Manual.

If we accepted your project plans and documentation for permit review prior to January 1, 2016, you may use the 2009 Stormwater Code and Manual.

For more information about the 2016 Stormwater code, visit our website or email

2016 Stormwater Code and Manual Update Public Meeting and Public Hearing

Want to let us know what you think about the 2016 Stormwater Manual? Then don’t miss our public meeting on September 30, from 4:30 to 6:00 p.m., in Seattle Municipal Tower (700 5th Ave.), room 2240. The final draft of the 2016 Stormwater Manual will be available on our website before the meeting. The Stormwater Manual is a Director’s Rule that interprets the Stormwater Code requirements. Director’s Rules are binding rules adopted according to the administration section in the Seattle Municipal Code.

Want to comment on the 2016 Stormwater Code Update? Then don’t miss the City Council’s public hearing on September 11, at 2:00 p.m. in Seattle City Hall Council Chambers. The draft documents of the 2016 Stormwater Code and other code changes regarding the applicability of code revisions to development projects are available for your review on our website. Stormwater Code is legislation that will be passed by Council and must be approved by the Mayor.

You can also provide written comments on the draft 2016 Stormwater Code update by sending them to or to:

Sherell Ehlers
Seattle Public Utilities
700 Fifth Ave, Suite 4900
PO Box 34018
Seattle, WA  98124-4018

Our official public comment period on the draft 2016 Stormwater Code ended on June 30, 2015. However, we will continue to take written comments until we send final recommendations to the Mayor for transmittal to the City Council. Email correspondence is preferred.

If you’re suggesting a code change, include as much of the following information as you can:

  • Number and title of the code section (for example:  22.805.070.D.a)
  • Specific code language you’re suggesting
  • Explanation of why the code should be changed