Crews begin excavating 120-foot shaft for water quality project

If you live or work near 24th Ave NW and Shilshole, you can expect an uptick in truck traffic as crews are excavating the 120-foot-deep vertical shaft for the water quality project along the Ship Canal.

According to Seattle Public Utilities, the shaft excavation will take about two months. They say there will be more trucks traveling in and out of the area as soil is hauled off site. SPU says the trucks will travel along Shilshole to 46th, up to Market St, then north along 15th Ave NW to Holman Road and then north on I-5.

The multi-year project will eventually connect Ballard’s existing sewer system to the new storage tunnel that will run parallel to the Ship Canal between Ballard and Wallingford.

As part of the project, new conveyance pipes will be built along 24th Ave NW, 28th Ave NW, and NW 56th St. SPU says the work will involve removing and restoring the traffic circle at 28th and 56th: they ask that any nearby residents that maintain the landscaping in the traffic circle contact the project team and weigh in on how the circle should be restored (email

The soil stabilization work in East Ballard next to Fred Meyer will also continue: SPU says you can expect the following through late December:

  • NW 45th St closed to traffic; vehicles must detour onto NW 46th St.
  • 11th Ave NW open with periodic one-lane closures. During a closure, two-way traffic will be maintained via one lane controlled by flaggers.
  • Burke-Gilman Trail users remain detoured to the north side of NW 45th St; flaggers to help direct traffic. Please follow all detour guidance on site. Bicyclists must cross train tracks at 90-degree angles.
  • Noise and vibrations typical of a construction site.

Regular work hours for both Ballard sites will be Monday through Friday, 7am to 5pm. Night and weekend work may occur to maintain progress.

For information on traffic impacts through 2022, visit the SPU Ship Canal Water Quality Project website.

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