East Montlake Pump Station & Force Main Improvements

Project Description

The Montlake 20 basin is a combined sewer basin on the east side of Union Bay. In this area, stormwater and sewage in the basin are collected and flow to Pump Station 13, which is located in East Montlake Park.

During heavy rain events, high volumes of stormwater can overwhelm the pump station causing an overflow into Union Bay, which can be harmful to humans and the environment.

Seattle Public Utilities (SPU) is upgrading the pumping capacity of Pump Station 13 to lessen the occurrence of combined sewer overflows (CSOs).

This work will also upgrade the pump station and connecting pipes, which will minimize the risk of system failure. This involves working on the force main that runs in the right-of-way along the north side of E Shelby St.


Pump Station 13 is located in East Montlake Park. East Montlake Park is bounded on the north by the Montlake Cut, on the east by Union Bay, on the south by Washington State Route 520, and on the west by E Park Drive E.

What's Happening Now?

Design is complete and the project team is preparing for construction, which is scheduled to begin as early as March 2020.
Because of the location, the project team is actively working to minimize potential construction impacts to residents, commuters, wildlife, and habitat to the extent possible.

SPU will share additional information once we have a contractor onboard. In the meantime, please review the Project Fact Sheet for more information.

Community Benefits

As part of the Plan to Protect Seattle’s Waterways, SPU will make improvements to Pump Station 13 and the force main along E. Shelby St.
This project will result in:

  • Improvements to sewer infrastructure to reduce the risk of failure.
  • Better water quality through the reduction of combined sewer overflows (CSOs) into Union Bay.
  • Improved working conditions for SPU pump station maintenance crews.
  • Replacement of concrete walkway to meet ADA standards as well as improved landscaping and lighting near the pump station in East Montlake Park.Improved maintenance vehicle access area in East Montlake Park.

Anticipated Impacts

Much of the work will occur in or next to the pump station in East Montlake Park. Crews will also perform non-excavation repairs to the section of pipe that goes under E. Montlake to avoid traffic disruptions to the arterial. The section connected to the pump station (marked in red) may require excavation for replacement, but SPU is exploring the option of non-excavation repairs.

Residents can expect construction traffic, noise, dust, and vibrations. In addition, there will be slowed vehicle traffic, temporary lane closures, and parking restrictions in or near the work area.

Community Engagement

If you're interested in learning more and finding out about upcoming community engagement events, please sign up to receive project email updates.


If you are interested in receiving updates about the project schedule, please sign up for the project listserv.
Mid to Late 2018

  • Project team worked on design and permitting
  • Community outreach about the project

Early to Mid-2019

  • Continue working on project design

Late 2019

  • Finalize design and start preparing for construction
  • Provide project update to the community

Early 2020

  • Pre-construction community notification and outreach
  • Construction work is scheduled to begin as soon as March 2020
  • Construction is expected to take 6 to 10 months
  • Continuing updating the community, as needed, during construction

Late 2020

  • Construction completion and final site restoration

*Tentative schedule as of November 2019 assuming that there are no project delays due to the permitting process, weather, or other factors.