Drainage & Wastewater Reports

Seattle Public Utilities (SPU) compiles documents with key information about, and/or analysis of, drainage and sewer system performance including steps we are taking to address combined sewer overflows. These reports inform future investments in and decisions about Seattle’s drainage and sewer infrastructure. Note: The term “wastewater system” is used for the sewer system in these documents.

  • Shape Our Water: This page includes documents about the performance of our drainage and wastewater systems including information about system capacity, water quality, creek and shoreline health, and system pressures and shocks.

  • Combined Sewer Overflow Reports and Requirements: In compliance with our Clean Water Act permit requirements, we provide annual reports about SPU actions to improve the wastewater collection system and reduce combined sewer overflows.