Combined Sewer Overflow Reports & Requirements

Seattle must meet state and federal regulatory requirements in order to comply with the Clean Water Act. The program is regulated via a National Pollutant Discharge Elimination System (NPDES) permit.

One requirement in the current permit is to provide realtime online reporting of overflows in Seattle.

Annual Reports

All reports in PDF format.

2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012

Consent Decree

In July 2013, Seattle entered into a Consent Decree (PDF) with the Environmental Protection Agency, Department of Justice, and the Washington State Department of Ecology to reduce sewer overflows (SSOs) and combined sewer overflows (CSOs). While Seattle had been reducing CSOs since the 1960s, our landmark Consent Decree required additional commitments. Our 2015 Plan to Protect Seattle’s Waterways was completed as a Consent Decree Requirement and included both a Long Term Control Plan for controlling CSOs and an Integrated Plan to also addressed stormwater pollution:

On May 22, 2025, a modification of our 2013 Consent Decree went into effect.

Learn more about our next steps in the Drainage and Sewer Plans section of our website.

Learn more about SPU’s ongoing Achievements in Reducing Combined Sewer Overflows.

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000
SPUCustomerService@seattle.gov

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Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.