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Combined sewer overflow status

This site is a joint effort by King County and the City of Seattle.

For questions about the King County Protecting Our Waters Program, please contact John Phillips.

For questions about the City of Seattle Sewage Overflow Prevention Program, please contact

What's happening in your waterway? Current CSO information to inform your choices

King County and City of Seattle CSOs -- public notification, posting

King County has partnered with the City of Seattle, Seattle-King County Health Department, and the Department of Ecology to develop a combined sewer overflow (CSO) public notification program consisting of:

  • King County and City of Seattle CSO LocationsReal-time CSO status in the Seattle area (a pilot to bring King County and Seattle CSO information together in one website)
  • Web site (maintained by Public Health) to answer health concerns about CSOs
  • Warning signs near CSO outfalls
  • CSO information line (206-205-1151)