Stormwater manuals

Our stormwater manuals provide stormwater permit implementation and management guidance. To determine which manual you need, contact your municipality or permit administrator.

Western Washington

2019 Stormwater Management Manual for Western Washington

Previous versions

2012 Stormwater Management Manual for Western Washington, as Amended in December 2014
2012 Stormwater Management Manual for Western Washington
2005 Stormwater Management Manual for Western Washington

2001 Stormwater Management Manual for Western Washington
1992 Stormwater Management Manual for the Puget Sound Basin

Eastern Washington

Stormwater Management Manual for Eastern Washington (2019)

Previous versions

Stormwater Management Manual for Eastern Washington (2004)
- Corrections and Clarifications to the Stormwater Management Manual for Eastern Washington (2004)

Order a hard copy or CD

Between versions: What changed and why?

Other manuals for management and design

Manual equivalency

In some cases, municipal stormwater permittees have the option of either adopting portions of the appropriate Stormwater Manual or portions of a regional manual determined to be equivalent to the Ecology manual.

Other resources

Use this guidance for developing your Underground Injection Control (UIC) Stormwater Management Program (SWMP)
We provide the Western Washington Hydrology Model (WWHM) to support designers to model BMPs.
Learn how the SWMMWW and Municipal Stormwater Permits cross-reference.
Read Ecology's 2013 Focus Sheet on Bioretention Soil Media
Looking for your general stormwater permit page?
For more information and resources, please see our stormwater guidance pages.

Contact information

Amanda Heye
Stormwater engineer
amanda.heye@ecy.wa.gov
360-407-6457

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