Waterway Protection

Photo of girls on a ferry

Additional Information

Why bother? Rain collects pollution.

While raw sewage in our waterways poses health risks for people, polluted stormwater runoff also has a big impact on water quality. Rain lands on streets, yards, and other places, where it collects pollution such as:

  • pet waste
  • oil and heavy metals from vehicles
  • fertilizers and pesticides from yards

Those pollutants run off with the rain into the local waterway.

Seattle Public Utilities (SPU) completed a long-range plan and comprehensive strategy to protect Seattle's waterways. The plan:

  • Identifies areas of Seattle where projects are needed to reduce combined sewage overflows (CSOs)
  • Evaluates solutions for reducing CSOs in these areas
  • Identifies three additional areas where projects to reduce polluted stormwater runoff will improve water quality:
  • Recommends a schedule for designing and constructing projects (2015-2030)
  • Estimates program costs and rate impacts on City customer bills
  • Considers public and stakeholder input


Read the Plan


The Consent Decree

The plan describes how SPU will meet the requirements of the consent decree agreed to with federal regulators. This will enable the City of Seattle to comply with the Clean Water Act and state regulations, protect our waterways, and sustain our quality of life.

Complete consent decree

Glossary of terms (pdf)