Drainage Manual - Past Edition
Snohomish County Drainage Manual Effective from September 21, 1998 to July 1, 2006
- 1992 Department of Ecology Stormwater Manual - Volume I (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume II (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume III (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume IV (PDF)
- September 21, 1998 Snohomish County addendum (PDF) to 1992 Ecology Stormwater Manual
Snohomish County Drainage Manual Effective from July 1, 2006 to August 18, 2008
- 1992 Department of Ecology Stormwater Manual - Volume I (PDF)
- 2005 Department of Ecology Stormwater Manual - Volume II (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume III (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume IV (PDF)
- September 21, 1998 Snohomish County addendum (PDF) to 1992 Ecology Stormwater Manual
Snohomish County Drainage Manual Effective from August 18, 2008 to October 19, 2009
- 1992 Department of Ecology Stormwater Manual - Volume I (PDF)
- 2005 Department of Ecology Stormwater Manual - Volume II (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume III (PDF)
- 2008 Snohomish County Drainage Volume IV (PDF)
- September 21, 1998 Snohomish County addendum (PDF) to 1992 Ecology Stormwater Manual
Snohomish County Drainage Manual Effective from October 19, 2009 to September 30, 2010
- 1992 Department of Ecology Stormwater Manual - Volume I (PDF)
- 2005 Department of Ecology Stormwater Manual - Volume II (PDF)
- 1992 Department of Ecology Stormwater Manual - Volume III (PDF)
- October 5, 2009 Snohomish County Addendum to Volume III (PDF)
- 2008 Snohomish County Drainage Volume IV (PDF)
- September 21, 1998 Snohomish County addendum (PDF) to 1992 Ecology Stormwater Manual
Snohomish County Drainage Manual Effective from October 1, 2010 to January 22, 2016
- Volume I (PDF) - Minimum Technical Requirements
- Volume II (PDF) - Construction Stormwater Pollution prevention best management practices (BMPs)
- Volume III (PDF) - Hydrologic Analysis and Flow Control BMPs
- Volume IV (PDF) - Source Control BMPs
- Volume V (PDF) - Runoff Control BMPs
Snohomish County Drainage Manual Effective January 23, 2016 to June 30, 2021
- Volume I (PDF) - Minimum Technical Requirements
- Volume II (PDF) - Construction Stormwater Pollution prevention best management practices (BMPs)
- Volume III (PDF) - Hydrologic Analysis and Flow Control BMPs
- Volume IV (PDF) - Source Control BMPs
- Volume V (PDF) - Runoff Control BMPs