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 July 15, 2016.
  • North Henderson Basin North Henderson project area.

What & Why?

What's happening now?

Construction will be underway on the Seward Park site between early 2015 and mid 2017. The park remains open, but parking will be affected. View parking map (pdf).

October 26

Construction activities at the Seward Park site:

Work continues on the inside of the completed tank – including installation of piping, electrical lines and mechanical equipment necessary for operation of the tank.

On Saturday, November 5, the contractor will be on-site after 9 a.m. to remove a construction trailer. Also, on Friday, November 11 – Veterans Day – work is expected to take place on-site between 9 a.m. and 6 p.m.

Site grading and utilities work is ongoing and is expected to create noise near the south end of the site during working hours. Shoreline enhancement work will continue throughout October and is estimated to be complete by the end of November 2016.

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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