Puget Sound Olympia

Municipal Stormwater

Stormwater Action Monitoring

To improve stormwater management, reduce pollution, improve water quality, and reduce flooding by measuring stormwater impacts on the environment and evaluating the effectiveness of stormwater management actions. SAM was designed to meet MS4 permittee stormwater monitoring needs, as well as provide the structure, transparency, and accountability for other stakeholders to join.

Stormwater Action Monitoring (SAM), formerly the Regional Stormwater Monitoring Program (RSMP), is:

  • Collaborative.
  • Regional.
  • Funded
    • By permittees in Western Washington: 91 cities, towns, counties; 2 ports; WSDOT
    • In-kind from Ecology, WSDA, USGS, Redmond, Penn Cove Shellfish, Cedar Grove, hundreds of mussel monitoring volunteers

Learn more about how SAM works and why our work is important.

Stormwater Work Group (SWG), an independent stakeholder committee, oversees implementation of SAM and Ecology is the program manager. SWG outlined an overall strategy for a Stormwater Assessment and Monitoring Program for Puget Sound (SWAMPPS) with detailed technical appendices , and specific Recommendations for Municipal Stormwater Permit Monitoring.

SAM Findings Symposium, June 1,2017

Symposium presentations

This symposium was the first showcase of all the SAM studies to date. A status update or interim findings were given on the active projects for permittees to gain awareness of the wide range of monitoring studies underway at SAM.

Keep in touch

Sign up for the Stormwater Action Monitoring listserv for newsletters, updates, and events.

For a bimonthly update, join the Stormwater Work Group Reporter list. For more detail, sign up for Stormwater Work Group agendas and meeting notes.

Status and Trends in Receiving Waters

Goals: to measure whether things are getting better or worse and identify patterns in healthy and impaired Puget Lowland streams and Puget Sound urban shoreline areas.

Effectiveness Monitoring of Stormwater Management Program Activities

Goals: to provide widely applicable information about what works and what doesn’t work in certain situations, and how to improve stormwater management.

Source Identification Information Repository (SIDIR)

Goals: to provide information about source identification and elimination methods and identify opportunities for regional solutions to common illicit discharges and pollution problems.

Administration of Pooled Funds

Goals: to provide credible and transparent accountability for expenditures of permittee funds to implement SAM.



Stormwater Action Monitoring logo

NEW 10/9/2017Source Control Effectiveness Study Final Report

NEW 10/9/2017SAM Newsletter #3

SAM Newsletter #2

SAM Newsletter #1

Reducing Toxicity in Salmon with Bioretention Fact Sheet

Nearshore Bacteria Data Compilation Fact Sheet


SAM 2015/16 Mussel Monitoring Survey - Final Report


Illicit Discharge Detection and Elimination (IDDE) Regional Data Evaluation for Western Washington


2016 Annual Report


Bioretention toxicity reduction study finds the 60/40 bioretention soil mix prevents toxicity to adult and embryonic Coho salmon (LID Receiving Water tab)