Project Description

Construction crews working for the City of Tacoma reached a large milestone in July 2022 with the successful completion of their third and final tunnel drive under the light rail tracks at Pacific Ave. Crews continue storm drain and watermain installation along Jefferson Ave. Crews are performing restoration activities at or near 1147 Dock St, 15th, 17th and Prairie Line Trail, and Pacific Ave. Crews are on track to complete work in fall 2022.

City of Tacoma hired design-build team James W. Fowler Co. and Kennedy/Jenks Consultants to design and construct a large 60-inch diameter interceptor stormwater pipeline and a new outfall into the Thea Foss Waterway. Work began in fall 2021 and will be complete in fall 2022. This stormwater improvement project is an important part of the underground network of pipes that help reduce flooding in and around the downtown area.

Project Goals

• Address flooding that occurs in the lower downtown area due to capacity limitations in the existing stormwater system.

• Provide stormwater conveyance capacity for future growth in the downtown area.

• Deliver project improvements that represent the “best value” to Tacoma’s surface water ratepayers.

• Mitigate construction impacts on the downtown community, including adjacent local businesses and the public.

Project Benefits

This stormwater improvement project is an important part of the underground network of pipes that help reduce flooding in and around the downtown area. The City is replacing this pipe in efforts to improve existing storm sewer system capacity, help reduce flooding events, and sustainably support future growth in the downtown area.

Project Video

Location of Project

Construction will occur in the downtown area along S. 19th Street, Jefferson Avenue, S. 17th Street Prairie Line Trail, S. 15th Street and A St., and Dock Street. All work will be done within the city right of way. Scroll down for project updates for each location.

Construction Methods

Most of the sewer pipe will be installed using open-cut construction. In open-cut construction, crews dig from the surface to the pipe, depth, lay the pipe, then cover the pipe and restore the surface. 

There are a few areas that require a trenchless or “microtunneling” method. This method does not require digging from the surface to the pipe depth. Instead, two shaft are built on either end of the pipe. Then the pipe is installed using a hammer, auger, drill, or microtunneling machine. This method is only feasible in certain types of soils and conditions.

We expect to use trenchless construction in the following places along the stormwater interceptor pipeline:

• Under Dock Street
• Under the BNSF railroad tracks
• Under the Pacific Avenue / Link Light Rail crossing 

Construction Impacts

During construction you can expect:

• Weekday work hours, 7 AM – 5 PM. Minimal night and weekend work may be required.
• Construction noise, dirt, and vibrations
• Lane restrictions
• Full street closures. Local access will be maintained.
• Pedestrian detours
• Parking and delivery restrictions

Construction Update (August 2022)

South 19th St. and Jefferson Ave.: 

Starting as early as August 22, 2022, crews will close the intersection at S. 19th St. and Market St. during daytime hours to install a 60-inch surface water pipe. The intersection will be closed during daytime hours, 7 AM to 5 PM. The intersection will reopen to traffic outside of work hours.

Crews continue to work along Jefferson Ave. and S. 19th St. to complete installation of a storm drain and watermain. This work will continue through November 2022.

While the intersection at Market St. and S. 19th St. is closed, traffic will be detoured using S .17th Street, Pacific Ave., and S. 21st St. Pedestrian detours will be in effect.

South 17th Street between Pacific Avenue and Commerce Street: 

Crews completed tunnel boring work and will be backfilling and restoring pavement. The detour at S. 17th St. and Pacific Ave. will reopen to traffic as early as August 22nd. Crews completed the storm drain tie in and grouting work near Prairie Line Trail and began restoration of the area. Restoration is anticipated to be complete by fall 2022.

1147 Dock Street: 

Crews completed installation of the new stormwater pipeline and outfall that will serve as a discharge into the Thea Foss Waterway.  Crews will continue work to permanently restore the area. Crews have begun removing sheet piles and restoring the grassy knoll area near 15th and Dock Street. Restoration is anticipated to be complete by fall 2022.

The outfall is designed to support stormwater drainage of more than 90,000 gallons per minute. At that flow rate, it would take about seven minutes to fill an Olympic-size swimming pool.

Contact Information

For additional information, call the project hotline at (253) 279-5509 or email the project team. To signup for project news and updates, click here.