Stormwater Management Program

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What’s happening?

Each year, the City is required to create a Stormwater Management Program (SWMP) Plan. The SWMP Plan lays out the actions we will take to protect our streams, rivers, lakes, wetlands, aquifers, and Puget Sound from stormwater runoff. It’s like a roadmap that helps us plan for the coming year and shows how we meet the requirements of our Municipal Stormwater Permit.

The Draft 2026 SWMP Plan includes:

  • Program planning
  • Community education and outreach
  • Public involvement
  • Stormwater system mapping
  • Finding and stopping illegal dumping, leaks and spills
  • Helping businesses
  • Inspecting privately owned stormwater systems
  • Managing runoff from existing development
  • Addressing runoff from development activities
  • Inspecting, operating and maintaining public infrastructure
  • Addressing watershed clean-up plans
  • Monitoring and documenting progress

Learn more about each under the "SWMP Plan Sections" tab below.

What is stormwater management?

As our city grows there are more hard surfaces like roadways, parking lots and roofs. Rainwater can’t soak into hard surfaces, so it becomes stormwater runoff. Stormwater management refers to the tools and programs that we have put in place to reduce this runoff from flowing into our streets and waterways while also improving water quality. By managing stormwater we help keep our community safe and water clean for people and wildlife.

Why is this important?

Stormwater pollution is one of the biggest threats to our streams, wetlands, lakes and Puget Sound! When stormwater travels over hard surfaces, it picks up chemicals, tire particles, nutrients, oil and other pollutants, and enters our municipal stormwater system. Sometimes treatment happens before stormwater enters local waterways, but often not.

Water pollution harms aquatic creatures like salmon and orca and their habitats, and impacts activities that we enjoy, like fishing, swimming, and shellfish harvesting.

What’s happening?

Each year, the City is required to create a Stormwater Management Program (SWMP) Plan. The SWMP Plan lays out the actions we will take to protect our streams, rivers, lakes, wetlands, aquifers, and Puget Sound from stormwater runoff. It’s like a roadmap that helps us plan for the coming year and shows how we meet the requirements of our Municipal Stormwater Permit.

The Draft 2026 SWMP Plan includes:

  • Program planning
  • Community education and outreach
  • Public involvement
  • Stormwater system mapping
  • Finding and stopping illegal dumping, leaks and spills
  • Helping businesses
  • Inspecting privately owned stormwater systems
  • Managing runoff from existing development
  • Addressing runoff from development activities
  • Inspecting, operating and maintaining public infrastructure
  • Addressing watershed clean-up plans
  • Monitoring and documenting progress

Learn more about each under the "SWMP Plan Sections" tab below.

What is stormwater management?

As our city grows there are more hard surfaces like roadways, parking lots and roofs. Rainwater can’t soak into hard surfaces, so it becomes stormwater runoff. Stormwater management refers to the tools and programs that we have put in place to reduce this runoff from flowing into our streets and waterways while also improving water quality. By managing stormwater we help keep our community safe and water clean for people and wildlife.

Why is this important?

Stormwater pollution is one of the biggest threats to our streams, wetlands, lakes and Puget Sound! When stormwater travels over hard surfaces, it picks up chemicals, tire particles, nutrients, oil and other pollutants, and enters our municipal stormwater system. Sometimes treatment happens before stormwater enters local waterways, but often not.

Water pollution harms aquatic creatures like salmon and orca and their habitats, and impacts activities that we enjoy, like fishing, swimming, and shellfish harvesting.

  • Implementing Water Clean-up Plans

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    Also called Total Maximum Daily Loads, water clean-up plans are created by the Department of Ecology for specific watersheds. TMDLs are used to address polluted waters by identifying the sources of pollution and determining how much each source needs to be reduced to meet water quality standards. The plans specify what the problem is and actions we must take to address the issue. Under the Permit, Olympia has TMDL requirements for three watersheds. This includes Henderson Inlet, Deschutes River and Budd Inlet.

    What we’re doing:

    • Henderson Inlet Watershed - Fecal Coliform Bacteria Water Quality Improvement Project
      • Through site plan review and permitting, development within the Woodard Creek basin requires phosphorus controls for stormwater treatment.
      • The Cities of Lacey and Olympia updated their coordinating sampling plan to reflect new permit requirements in 2024. The City of Olympia will continue to sample Taylor Wetlands outfall at least once during the 2025-2026 wet season.
    • Deschutes River Watershed
      • Per City code, limit the amount of impervious (hard) surfaces and promote the use of low-impact development (“LID”) approaches.
      • Apply the City’s Shoreline Master Program and Critical Area Ordinance which requires stream buffers for new development.
      • Promote tree planting and restoration activities through our Habitat Stewardship Program, prioritizing natural areas buffering wetlands and streams.
    • Budd Inlet Dissolved Oxygen
      • Conduct an enhanced street sweeping program, prioritizing roadways with high-use, curbed streets, canopy cover, and road sections with no stormwater treatment that drain to Budd Inlet.
      • Analyze nutrient output from our stormwater system to Budd Inlet. From the analysis identify high priority areas for stormwater management.
      • Screen high priority areas to discover why nutrients are reaching Puget Sound.
      • Consider TMDL in our watershed prioritization process (SMAP) and in our stormwater investment prioritization.

  • Monitoring and Documenting Progress

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    A key part of stormwater management is understanding how we can improve our programs and methods to protect downstream waters and our community. The Permit allows jurisdictions to do monitoring and assessment within their jurisdiction or contribute to a regional fund called Stormwater Action Monitoring (SAM). SAM projects are designed to produce regionally relevant findings. They include effectiveness studies, status and trends studies, and source identification studies. Studies are proposed and selected by the contributing members. The studies help us make informed decisions based on the best available science, local knowledge and experience. With the goal of continually making improvements to our stormwater programs and the health of our community, while demonstrating accountability for our actions.

    What we’re doing:

    • Olympia participates in SAM to meet Permit requirements. City staff are active in the decision-making process and participate in SAM sub-committees. Additionally, staff have sponsored, been technical advisors and proposed SAM regional studies. For information, visit the SAM website: https://ecology.wa.gov/regulations-permits/reporting-requirements/stormwater-monitoring/stormwater-action-monitoring
      • Olympia contributes $14,093.00 annually to Regional Status and Trends Monitoring.
      • Olympia contributes $20,857.00 annually to Effectiveness and Source Identification Studies.
    • Through our outreach programs Olympia conducts water quality sampling and aquatic macroinvertebrate (stream bug) sampling in several creeks to evaluate stream health. While not required under the permit, these activities complement and inform other stormwater management activities.
    • Olympia will continue to track and maintain records of Monitoring and Assessment activities and summarize these activities in the Annual Compliance Report.
Page last updated: 05 Jan 2026, 11:05 AM