Investing in the Health of the Sound and the Future of Our Region

Welcome to the Ship Canal Water Quality Project website! We’re happy you’re here.

Currently, the Seattle Public Utilities is planning to continue with construction in your area. We are working closely with our Public Health – Seattle & King County partners, our construction management teams, and private contractors to ensure that everyone supporting this project is cautious and safe. If there are changes to the construction schedule or planned work, we will notify you once public information is available.

The City of Seattle and King County are taking steps to protect the health of our community by making recommendations that are meant to slow the spread of novel coronavirus and reduce the number of people infected. Please learn more about COVID-19 at www.kingcounty.gov/covid. Thank you.

We will continue to share updates about construction progress on this website, as they become available.

An aerial map of the Ship Canal Water Quality Project site. The base map shows the projected storage tunnel location, which runs along Shilshole Avenue Northwest in Ballard to North 35th Street in Wallingford. Project areas are shown as purple boxes, sites include Ballard (located near the intersection of 24th Avenue Northwest and Northwest Market Street), East Ballard (located near the intersection of Northwest 45th Street and 9th Avenue Northwest), Fremont (located near the intersection of North 36th Street and 3rd Avenue Northwest), Queen Anne (located near the intersection of Queen Anne Avenue North and West Nickerson Street) and Wallingford (located near the intersection of Interlake Avenue and North 35th Street).
Project Area (Click or tap image to enlarge)

Click on the project areas to learn more

About the project

Seattle Public Utilities and King County Wastewater Treatment Division are building an underground storage tunnel to significantly reduce the amount of polluted stormwater (from rain) and sewage that flows into the Lake Washington Ship Canal, Salmon Bay, and Lake Union from our sewer system.

An aerial map of the Ship Canal Water Quality Project site. The base map shows the projected tunnel site as a dark blue line that runs from the eastern end of Fremont towards Ballard. A dotted line indicates the location of the existing pipe transfer, which runs from the end of the tunnel in Ballard to the West Point Treatment Plant, which is denoted as a black square. The areas served by the Ship Canal Water Quality project are highlighted in green and include: Crown Hill, Ballard, Fremont, Wallingford, Queen Anne, Capitol Hill and Downtown.
Map of storage tunnel alignment and the combined-sewer areas that will send flows to the new tunnel. (Click or tap image to enlarge)

Tunnel

Since the 1800s, 150 tunnels spanning over 70 miles have been constructed in Seattle for sewers, utility corridors, and transportation needs. The Ship Canal Water Quality Project includes a 2.7-mile, 18-ft and 10-in internal-diameter tunnel that will extend from Ballard to Wallingford. Tunneling operations will start in Ballard. The Ballard vertical access shaft will begin construction in 2020 and tunneling is planned to begin in 2021.

Ballard

Construction in Ballard is in full swing!

Work in Ballard began in late February 2020. For more details about this work, please see a copy of the construction flyer that went out to more than 2,100 businesses and residents near the work site.

For the first few months, crews will be:

  • Installing a 12-ft high sound wall
  • Installing stormwater controls
  • Installing dewatering equipment
  • Constructing a slurry wall
  • Preparing the site to support heavy machinery. This may include compacting soils, paving asphalt access roads, tree removal, and laying gravel
  • Installing artwork along the Shilshole Ave NW wall

Heavy equipment will move onto the site in April with the early stages of shaft construction starting in May.

aerial map of area between 24th avenue North West and Shilshole Avenue Northwest. Tunnel barging operations are southwest of the 24th avenue pier in Salmon Bay. Dotted lines along 24th Avenue Northwest and Northwest 56th Street indicate locations for conveyance pipe alignment and microtunnel placement. A dark blue line that runs through Shilshole Avenue Northwest denotes the storage tunnel.
Construction area map (Click or tap image to enlarge)

East Ballard

Construction starting as early as May!

Construction in East Ballard at NW 45th St and 11th Ave NW will begin as early as May! During the first two months of work, crews will:

  • Prepare the site. This may include setting up fencing and tree removal.
  • Install stormwater control and soil monitoring equipment
  • Re-locate an existing waterline
  • Stabilize soils for underground construction work
  • Re-route the Burke-Gilman Trail to the north side of NW 45th St
aerial map shows area on Northwest 45th Street and is between 11th Avenue North West and 9th Avenue Northwest. Grey dotted lines along 45th Avenue Northwest and indicate the future missing link route, orange dotted lines along 45th Avenue Northwest indicate the proposed trail detour and green dotted lines indicate the Burke-Gilman Trail. The solid blue line on 11th Avenue Northwest indicates underground pipes..
Construction area map (Click or tap image to enlarge)

Fremont

Construction starting as early as May!

Construction in Fremont will start as early as May near the intersection of Leary Way NW, NW 36th St, and 2nd Ave NW. During the first few months of construction, crews will:

  • Close NW 36th St between Leary Way NW and 3rd Ave NW and set up the construction site
  • Remove trees onsite
  • Remove an existing sidewalk on NW 36th St and existing utilities
  • Install stormwater control and soil monitoring equipment
  • Remove existing asphalt
  • Install a temporary storm drain bypass
aerial map of the project sitesituated between Leary Way Northwest and the Burke Gilman Trail. The dotted orange line along first avenue Northwest and Northwest 36th Street denotes the pedestrian detour. A small blue line that runs from the project area and across the Ship Canal represents the microtunnel placement.
Construction area map (Click or tap image to enlarge)

Queen Anne

Construction planned for August 2020

Construction in North Queen Anne is planned to begin in August 2020 and will take place near West Ewing Mini Park and along 3rd Ave W.

For the first few months, crews will:

  • Remove trees onsite
  • Install wheel stops and bollards
  • Install stormwater control and soil monitoring equipment
  • Re-route the Ship Canal trail
aerial map of project site situated along Third Avenue West and West Ewing Street. Green boxes within the project area indicate the following: underground pipes, cabinet, underground facility and drop shaft. A small blue line that runs from the project area and across the Ship Canal to Northwest 36th Street in Fremont represents the microtunnel placement.
Construction area map (Click or tap image to enlarge)

Wallingford

Construction activites resume in August 2020

Our contractor installed a screen wall on the northern and eastern sides of the project site at Interlake Ave N and N 35th St. Additional construction activities are scheduled to begin at this site in August. Why the gap in schedule? To be most efficient, we used the same crew and equipment to put up our Ballard and Wallingford screen walls, but we won't be ready to begin additional activities in Wallingford for another few months.

Beginning as early as August 2020, crews will:

  • Install stormwater control and soil monitoring equipment
  • Remove the existing fence, gate, posts and stairs
  • Remove existing asphalt, concrete and some trees
  • Remove existing utilities
  • Excavate and remove contaminated soils
aerial map project site situated at the intersection of Interlake Avenue North and North 35th Street.  A dark grey line that runs west from the project site along N 35th Street indicates the storage tunnel.
Construction area map (Click or tap image to enlarge)