Surface Water Management

Snohomish County's Surface Water Management (SWM) Division provides a variety of programs and services for reducing road and property flooding and preserving and improving the health of Snohomish County's water resources and natural systems. We focus on four areas of service:

  • Clean water in rivers, streams and lakes;
  • Habitat for fish and aquatic wildlife;
  • River flooding and erosion;
  • Stormwater drainage systems.

We work in partnership with the residents of Snohomish County. You can find us responding to water-quality problems and complaints, monitoring river levels during flood season, maintaining drainage systems, managing habitat improvement projects and more.

SWM's Mission, Values, and Priorities
Summary List of SWM Services

SWM Highlights

Proposed Surface Water Management Consolidation Ordinance


Snohomish County Surface Water Management (SWM) currently operates as three separate utilities—South County, Snohomish, and the Stillaguamish River Clean Water District—even though people pay the same rates and expect the same services countywide. This creates a wasteful administrative bureaucracy that is obsolete and inefficient, wasting resources and taxpayer dollars. SWM is proposing, through ordinance 17-020, to consolidate the three areas into a single district.

The reforms in Ordinance 17-020 will cut administrative costs, improve accountability, and provide better service to the public. This will eliminate hundreds of thousands of dollars of administrative overhead, allowing more money to be invested directly in public services. The proposal will also improve transparency and accountability by requiring new annual reporting to Council and the public. A successful small grants program, previously only found in the Stillaguamish River Clean Water District, will be expanded into a countywide program open to all ratepayers. This proposal does not include a rate increase.

A public hearing will be held Wednesday May 17, 2017 at 10:30 AM. Additional information about this proposal can be found in the links below.

Port Susan


The Port Susan Marine Stewardship Area is a haven for wildlife and a mecca for people to escape back into nature located on the Salish Sea in Snohomish County of Washington State.

2017 Stormwater Management Program Plan Available for Review


The 2017 National Pollutant Discharge Elimination System (NPDES) Stormwater Management Program (SWMP) Plan is available for review. This plan describes programs the County will implement in 2017 to comply with the NPDES municipal stormwater permit, which is a part of the federal Clean Water Act. Find out more about the NPDES permit, what the County does to meet its requirements, and how you can comment on these programs by visiting our NPDES page.

Lake Serene Project

Learn latest details about the Lake Serene Project.

SWM 2017 Annual Construction Plan - ACP

2017 ACP - Council Approved

SWM 2017-2022 Six-Year Capital Improvement Program (CIP)


2017-2022 CIP - Council Approved