Seattle Public Utilities Mami Hara, General Manager/CEO

North Henderson

  • North Henderson Project Site Mid July Aerial photo of North Henderson Combined Sewer Overflow Reduction project site January 2017.
  • North Henderson Basin North Henderson project area.

What & Why?

What's happening now?

March 21

Construction activities at the Seward Park site:

The Henderson North Combined Sewer Overflow Reduction Project will reach substantial completion this week, which means the contractor has completed the majority of contract work and the facility can be placed into operation. Over the next several weeks, the contractor will complete the final, smaller work items that remain, such as painting the parking lot, installing benches, completing the irrigation system, etc. Seattle Public Utilities and Seattle Parks and Recreation will also complete final inspections of the work in the next few weeks. The contractor’s work is expected to be fully complete by mid-April, with the possible exception of the final tennis court surfacing which requires warmer and drier weather. The contractor may have to return to complete this work if the weather does not cooperate by mid-April.

Project goals and benefits

This project will reduce the frequency of sewage overflows into Lake Washington to no more than one per year per outfall (on average). SPU plans to complete two new underground storage facilities in North Henderson to store excess combined sewage and stormwater during major rain. The underground storage facilities are in the following locations:


Ask Us

Alan Lord, PE, Project Manager
(206) 233-1565

Please specify the project site with your comments:

  • Seward Park (Basin 44) or
  • 57th Ave. S. right-of-way (Basin 45)

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