Drainage Manual

Current Manual (January 2016, November 2017 for Volume I)

The documents listed below compose the entire Snohomish County Drainage Manual. The drainage manual is used in concert with Snohomish County code and Snohomish County engineering design and development standards (EDDS).
  • Volume I - Minimum Technical Requirements
  • Volume II - Construction Stormwater Pollution prevention best management practices (BMPs)
  • Volume III - Hydrologic Analysis and Flow Control BMPs
  • Volume IV - Source Control BMPs
  • Volume V - Runoff Control BMPs