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Long-Term Control Plan

The Plan to Protect Seattle's Waterways

In 2012, 154 million gallons of untreated sewage and stormwater flowed into our lakes, creeks, and Puget Sound. Seattle Public Utilities is preparing a long-range plan that will create a comprehensive strategy to protect Seattle’s waterways reduce these Combined Sewer Overflows (CSOs).The plan:

  • Identifies areas of Seattle where CSO reduction projects are required
  • Evaluates solutions for reducing CSOs in affected areas
  • Selects a preferred alternative for each affected area
  • Recommends a schedule for designing and constructing projects (2016-2025)


Timeline of Plan Development (pdf)

Note: The Plan has changed based on community input and further technical analysis since the production of the Community Guide and video linked here. While some of the information has changed, these materials still provide a good general overview. Look for an updated Community Guide in June 2014.

Community Guide to the Plan - Spring 2013 (pdf)

Video overview of the Plan - Spring 2013

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)