Seattle Public Utilities Ray Hoffman, Director

North Henderson


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).

February 4

Construction activities at the Seward Park site:

  • Over the next several weeks, the construction team will continue to work on excavating soil where the new, buried CSO storage tank will be constructed. Excavation work is expected to be complete in mid-February.
  • Construction of the new concrete storage tank will begin in early February. Concrete trucks and placement of reinforcing steel will create noise. In addition, some longer work days will be required to complete concrete finishing before the concrete hardens. We will provide notice before these longer days. Concrete work is expected to continue until late summer 2016.
  • The construction team expects to be on site on Saturday, February 6 and 13 between 9 a.m. and 5 p.m. to continue working on excavation and grinding concrete shoring walls. There will be no dump trucks operating at these times. A Seattle Public Utilities (SPU) representative will be on site.
  • The construction team also expects to be on site on Monday, February 15 (Presidents Day) between 9 a.m. and 5 p.m. Trucks will be hauling material to and from the site this day. An SPU representative will be on site during this time.

Construction activities at 57TH Avenue South near Martha Washington Park:

  • The new facility at the end of 57th Ave South is complete and in operation. During the next month, the team will complete work to improve the roadway runoff at the end of 57th Avenue South. Site maintenance activities will continue during this time.

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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