The City of Tacoma Stormwater Management Manual describes the Minimum Requirements and technical standards for stormwater management in the City of Tacoma.
The City of Tacoma regularly updates its Stormwater Management Manual (previously called the Surface Water Management Manual) to comply with the most recent National Pollutant Discharge Elimination System (NPDES) permit, to clarify information and to incorporate updated policies.
Draft 2026 Stormwater Management Manual (SWMM)
The Washington State Department of Ecology issued a new National Pollutant Discharge Elimination System (NPDES) Phase I Municipal Stormwater Permit (Permit) that became effective August 1, 2024.
As part of Permit Compliance, the City of Tacoma is updating the July 2021 City of Tacoma Stormwater Management Manual (SWMM).
The City is accepting comments on the draft 2026 SWMM through May 16, 2025.
To submit comments on the draft SWMM, fill out the Comment Spreadsheet Template and email it to swmupdates@cityoftacoma.org.
The following documents are available for review and comment:
The City is hosting two webinars to present the proposed changes. Registration is required. Note: Both webinars cover the same content – it is not necessary to attend both.
Webinar 1: April 25, 2025 from 12:00 - 1:00p.m. Click here to register.
Webinar 2: May 6, 2025 from 12:00 - 1:00p.m. Click here to register.
After registering you will receive a confirmation email containing information about joining the webinar.
If you have any questions email swmupdates@cityoftacoma.org.
2021 Stormwater Management Manual (SWMM)
The July 2021 Stormwater Management Manual is applicable to the following projects:
- All complete applications submitted one or after July 1, 2021.
- All complete applications submitted prior to November 24, 2015 that have not started construction by July 1, 2021. **Even if a construction permit has been approved and issued.**
- All complete applications submitted prior to July 1, 2021 that have not started construction by July 1, 2026.
Stormwater Management Manual WebBook
Training Materials
Full Day Recorded Training
Full Day Powerpoint Only
Full Day Stormwater Site Plan Example
Full Day Soils Report Example
Half Day Recorded Training
Half Day Powerpoint Only
Half Day Stormwater Site Plan Example
Half Day Operation and Maintenance Manual Example
SWMM Policy Documents
The following policy documents shall be used in conjunction with the SWMM:
Tip Sheets
The City of Tacoma developed several Tip Sheets to provide additional assistance on many topics.
Payment In-Lieu of Construction Program
Tip Sheet for Payment In-Lieu of Construction Program - Gravel Pit
Tip Sheet for Payment In-Lieu of Construction Program - Thea Foss Watershed
City of Tacoma Regional Stormwater Facility Plan (June 2016)
City of Tacoma Regional Stormwater Facility Plan - Attachment 1: Flett Creek Watershed (August 2017)
Addendum to Attachment 1: Flett Creek Watershed (June 2022)
Greater than 90% capacity has been used in the Gravel Pit facility. Potential participation in the program is very limited. There are no immediate plans to add capacity to continue the Payment In-Lieu of Construction Program for Flow Control. Once capacity has been fully used, the program for flow control will cease until future projects can be funded and constructed. Once the project ceases, all projects will be required to install site specific flow control facilities in order to meet MR#7 (if required). Potential projects cannot reserve limited capacity. Contact Mieke Hoppin (mhoppin@cityoftacoma.org) to check on available capacity for your project.
City of Tacoma Regional Stormwater Facility Plan – Attachment 2: Thea Foss Watershed (Sept 2022)
The City of Tacoma is currently in the design phase for a project that will alter the drainage basin for the Thea Foss Basin. This may affect which new development projects can participate in the program. Before completing an application for inclusion in the Thea Foss Program for a new development project contact Mieke Hoppin (mhoppin@cityoftacoma.org) to ensure that the project can utilize the program.
Application For Payment In-Lieu of Construction Program – Gravel Pit
Application for Payment In-Lieu of Construction Program – Foss Facilities (March 2025)
Voluntary Agreement and Covenant – Gravel Pit (March 2025)
Voluntary Agreement and Covenant – Foss Facilities (April 2025)
Previous SWMM Versions
For projects vested beginning August 1, 2016 to June 30, 2021.
For projects vested beginning January 7, 2016 to June 30, 2016.
2016 SWMM Related Documents
2016 Public Training Presentation
For projects vested beginning February 1, 2012 to January 6, 2016.
2012 SWMM Related Documents
Errata:
Errata to Volume 3 and Glossary (August 27, 2013)
Errata to Volume 3-Chapter 1 (April 4, 2012)
Errata to Volume 3-Chapter 10 and Volume 5-Chapter 3 (April 29, 2012)
Errata to Volume 3-Chapter 5 and Chapter 9 (October 30, 2012
Policy Updates for 2012 SWMM
Stormwater Facility Maintenance Standards (June 2015)
Infrastructure Protection Requirement (July 30, 2014)
Minimum Requirement #5 Roof Downspout Control Selection (August 13, 2013)
Infiltration Trench Sizing (August 13, 2013)
New Impervious Surface Definition (August 7, 2013)
Bituminous Surface Treatment Definition (June 19, 2013)
Training:
2012 Training Workshop Presentation
For projects vested beginning September 22, 2008 and ending January 31, 2012.
Policy Updates for 2008 SWMM
Revision to Detention Practices for the Leach Creek Watershed (January 28, 2009)
Proprietary Device Policy - (Rescind 2021)
Revision to Detention Practices for Flett Creek Watershed (May 13, 2008)
For projects vested prior to September 22, 2008.