Archived Project Updates
March 2021
Stormwater permit request for Wallingford Conveyance project
We have requested a Construction Stormwater General Permit for the Wallingford Conveyance project, which will install a 213-ft long, 36-in diameter pipeline along Stone Way and a 412-ft long, 42-in diameter pipeline along N 35th St to convey polluted stormwater and sewage from the Wallingford neighborhood into the storage tunnel. Stormwater from construction sites can carry debris and chemicals to close-by waterways and this permit will specify mitigation requirements to be implemented at our construction site to help reduce water pollution. Department of Ecology will monitor the performance of our mitigation measures through inspections and water quality assessments.
The 30-day public comment period for Department of Ecology began on February 23, 2021.
Thank you for submitting Tunnel Boring Machine (TBM) naming ideas!
Due to the overwhelming response (we received over 1,200 submissions!), we are pushing back the voting start a few days to allow for more time to be thoughtful in our selection process. Ship Canal team members will select their favorite submissions and put them to a public vote! Stay tuned for more information.
Be sure to check back in or sign up for our project email list for updates!
February 2021
Pieces of the Tunnel Boring Machine have started to arrive in Ballard
It's here! Our tunnel boring machine arrived from Germany and is making its way to Ballard from the Port of Tacoma. Because the machine is so big, it is arriving in pieces via several oversized deliveries and will be assembled at our Ballard site over the next few months. The photos below show crews unloading a section of the lower shield last week, and then what the machine will look like fully constructed.


January 2021
Construction progress in 2020
Construction is underway at all five project sites. As of December 2020, the secant pile wall in Queen Anne is complete, Fremont’s is nearing completion, and we are breaking ground on this activity in Wallingford. Soil stabilization in East Ballard continues, and we just reached a huge project milestone in Ballard - completing the concrete pour for the 14-ft thick, 87-ft wide shaft floor. We are thankful for your patience and support as we continue this essential work to reduce combined sewer overflows in our waterways by 2025.
Visit our Flickr page to see photos of recent construction activities.

December 2020
The Tunnel Boring Machine is headed to Seattle and will arrive in early 2021!
Our Tunnel Boring Machine has left Germany on a ship and is on its way to Seattle! Over the next few months this machine will make its way to the shores of the Puget Sound where it will be prepped to start boring a 2.7-mile tunnel from Ballard to Wallingford. Watch this video to learn more about the machine as it begins its journey west!

Seattle artist taking T-shirt donations through Dec 31
In Spring 2021 we will be installing a new round of temporary art installations along our construction sites. Interested in participating? Seattle artist Janelle Abbott is taking t-shirt donations now through Dec. 31 to create her piece in Wallingford. Learn about how you can donate t-shirts for the installation.
November 2020
Secant pile wall construction begins in Queen Anne
Starting November 9, 2020, crews began construction on the secant pile wall at the Queen Anne site. This work is expected to be complete in late-December. A secant pile wall is used to support underground excavations. It is made up of overlapping vertical concrete piles, which together hold back surrounding soil to allow for excavation and underground construction. To create a pile, a hole is bored into the ground using a drilling machine and is filled with concrete. During this phase of construction, you should anticipate:
- More heavy equipment on site like the drilling machine, crane, rebar cages and trucks traveling and out of the site.
- Noise and vibration from the drilling machine. You may be able to feel the vibration which is expected. We are monitoring vibration levels on site to ensure they are within allowable levels.
- The West Ewing Mini Park parking lot to be closed. This closure is anticipated to last through mid-2023.
- A localized Ship Canal Trail detour through summer 2022. You can view the detour here.

October 2020
Vertical shaft excavation started in Ballard
In early October, crews began excavation of the 120-ft deep, 87-ft wide vertical shaft at the Ballard site (see photo from the week of Oct. 5). This work is expected to be complete in mid-November. Once excavation is complete, the contractor will construct the interior walls with reinforced concrete, including the 14-ft thick base slab. The shaft will be the launch site for the tunnel boring machine in 2021.
This shaft will ultimately be part of the future Ballard pump station. The pump station will be used to drain water from the storage tunnel and send the water to the West Point treatment plant. It will also be used to provide maintenance access to the storage tunnel.

Meet the artists for our construction sites
Our first round of temporary art is now installed in four neighborhoods. Check out the new videos from our artists, sharing their background and inspiration for their installations, on the art tab.

September 2020
Getting ready for secant piles in Fremont and Queen Anne
In September, we’re planning to start shaft construction in Fremont and Queen Anne. Shaft construction will start with installing “secant pile” walls. A secant pile wall is a type of construction used to support underground excavations. It is made up of overlapping vertical concrete piles, which together hold back surrounding soil to allow for excavation and underground construction. To create a pile, a hole is bored into the ground using a drilling machine and is filled with concrete. During this phase of construction, you should anticipate:
- More heavy equipment on site like the drilling machine, crane and rebar cages.
- Noise and vibration from the drilling machine. If you live or work within a few blocks of a site, you may be able to feel the vibration in your building. This is expected. We are monitoring vibration levels on site to ensure they are within allowable levels.
- Trucks in and out of the site to haul away excavated material and deliver concrete.
24th Ave NW pier to stay open for now
Ballard’s 24th Ave NW pier will remain open until further notice because our tunneling contractor does not currently need it for construction activities.
More art at our construction sites
Our first round of temporary art is now installed in four neighborhoods. Check out the new art tab on our website to learn more.

We’re on Flickr!
Seattle Public Utilities is now on Flickr! Check out albums uploaded this week highlighting temporary art and recent construction activities.
August 2020
Queen Anne trail detour update
We heard some community concerns about our previously proposed trail detour, so we worked with our contractor to move it. As early as mid-August, the trail will be moved just south of the existing trail, through the adjacent parking lot near Seattle Pacific University and West Ewing Mini Park.
The detour will be about 200 feet long and will be on a fully paved, 8-ft wide asphalt path that allows for two-way bike traffic. Trail users will be expected to yield to traffic on 3rd Ave W (same as now). This detour will remain in place until mid- to late 2022.
Keep a look out for signs on the trail. We will continue to update you on detour timing and any changes to detours via our project email list.
Bringing art to our construction sites
Did you know that there are both temporary and permanent artworks as part of the Ship Canal Water Quality Project?
There are two temporary artworks currently on display, including new art by Kalee Nelson and Crystal Christopherson that was installed on our Wallingford screen wall in late July. Elevating awareness of Missing Murdered Indigenous Women is the key goal of this temporary installation that includes a large-scale mural featuring traditional formline design of orcas.
Two more temporary artworks will be installed later this summer. Learn more about these pieces and the others that will be installed on our new Art page!

Construction underway in all neighborhoods!
As you scroll down this page, you’ll note that construction is going on in all five neighborhoods. For more detailed information, take a look at the fact sheets in our Project Library. We also encourage you to sign-up to our project email for any updates or changes to these schedules.
July 2020
Heads up trail detours coming!
The weather has been perfect for enjoying the trail and we want to make sure your trip goes as smoothly as possible. Here are some things you should know about upcoming trail detours.

East Ballard detour: As early as July 6, the Burke-Gilman Trail will be detoured from the south side of NW 45th St to the north side of NW 45th St between 11th Ave NW and 9th Ave NW, next to Fred Meyer. Two-way traffic will be maintained and flaggers will be on-site during the daytime. You will be directed to cross at a 90-degree angle to safely traverse the railroad tracks. This detour will remain in place until early 2023.
Queen Anne detour: As early as July 20, the Ship Canal Trail will be detoured onto 3rd Ave W, W Nickerson St and W Cremona St. This detour will remain in place until mid-2022.
Keep a look out for signs on the trail. As work progresses we will continue to update you on detour timing and any changes to detours will be shared via our project email list. Also, feel free to give us a call with any comments or suggestions on how to get the word out.
Construction starting in East Ballard and Fremont
In May and June, work will begin in the following locations:
- East Ballard: Work will take place on NW 45th St between 11th Ave NW and 9th Ave NW, and on 11th Ave NW just south of NW 45th St (near Fred Meyer)
- Fremont: Work will take place near the intersection of Leary Way NW, NW 36th St and 2nd Ave NW
Work at both sites will involve above- and below-ground construction to build new pipes and vertical shafts to connect the current combined sewer system overflow pipes to the new storage tunnel. During the first few months of work, crews will set up fencing, remove trees, curbs and existing asphalt, and stabilize soils to prepare for underground construction.
June 2020
Slurry wall construction begins in Ballard!
The slurry wall is a reinforced-concrete circular structure that will allow for safe excavation of the vertical shaft, which will ultimately bring stormwater and sewage flows into the new storage tunnel. The vertical shaft will also be the starting point for the tunnel boring machine that will begin its journey next year.
This work includes putting rebar steel cages inside 210-ft deep trenches and filling them with concrete. You can expect a large uptick in equipment and trucks going in and out of the work site to support this construction.

May 2020
It's a bird! It's a plane! It's a ...crane!
If you’re passing by our Ballard site, take a look up and check out the 250-ton crane towering over the work zone! The crane arrived from the mid-west in early April and crews have been busy assembling this massive piece of equipment.
The crane’s first assignment is to assist with slurry wall construction, one of the earliest phases for vertical shaft construction. It will be an 87-ft diameter, 210-ft deep, 4-ft thick reinforced concrete circular structure which will keep walls from collapsing during shaft excavation. You may experience additional noise and vibrations associated with this work.
Eventually, when the shaft is complete, we'll launch our tunnel boring machine through it!
Video of the Crane at the Ballard site

April 2020
Ballard’s 24th Ave NW Pier is open to the public!
We are pleased to share that the 24th Ave NW Pier has been temporarily re-opened to the public!
It will close again in late August to support construction activities, so we hope you get a chance to enjoy it while the sun is out this summer. Next year, crews will use the pier to carry tunnel spoils away by barge, which will reduce the number of truck trips needed and help mitigate traffic impacts.

February 2020
Construction in Ballard will begin as early as February 20
Starting the week of February 20, crews wil begin installing a 12’ high sound wall, stormwater controls, and dewatering equipment at the Ballard site. For more information, please see a copy of the construction flyer that went out to more than 2,100 businesses and residents near the work site.
Thank you!
Thank you to all who attended our Ballard drop-in session on Dec. 11, 2019, to learn more about construction in 2020. If you were not able to attend, we have uploaded a PDF version of the meeting boards for you to read at your leisure.
We appreciate the nearly 500 people who took time to fill out our survey on Ballard's 24th Ave NW street end designs. The survey is now closed. Stay tuned for next steps!
December 2019
Take our survey on Ballard's 24th Ave NW street end designs through Jan. 10 2020
Thank you to all who attended our Ballard drop-in session on Dec. 11, 2019, to learn more about construction in 2020. If you were not able to attend, we have uploaded a PDF version of the meeting boards for you to read at your leisure.
We would also love to hear your thoughts on the designs for the 24th Ave NW street end in Ballard. Please complete this survey available through Jan. 10, to provide feedback. We appreciate you taking the time to help us learn more about what you want to see once construction is complete!
View archived survey page.
November 2019
November Public art update
Over the summer, our Wallingford artist, RYAN! Feddersen, asked community members what water means to them. Their responses inspired her to create temporary artwork along the Ship Canal alignment that is activated by rain. Next time you’re walking along the tunnel alignment, take a look at the sidewalk and learn about why your neighbors value water. The installations are expected to last between four and six months.


October 2019
Early work at our Ballard site is underway!
Crews are preparing our Ballard site for tunneling. Here are the activities they’re working on:
- Replacing the 24th Ave NW Pier to prepare for removing tunnel spoils by barge
- Replacing the outfall pipe under the pier
- Relocating utilities
- Removing contaminated soils from the shaft site
Public art
Local artist Vaughn Bell is leading several artists to install permanent artwork along the storage tunnel alignment across all five neighborhoods. Artists will use a wide variety of mediums, materials and techniques to make our underground infrastructure and regional water quality improvements more visible.
Some goals of the Ship Canal public art include:
- Increasing public awareness of the function of water quality projects and infrastructure
- Making an invisible system more visible
- Connecting people to the flow of water in their city, their home and local ecology
- Creating meaningful, inspiring and thought-provoking art experiences in the public realm
Artwork will include both permanent and temporary installations.