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Jefferson and Hood Street Surface Water Interceptor

Project Description

The project will construct a large diameter interceptor stormwater pipeline and build a new outfall into the Thea Foss Waterway. This project will improve existing storm sewer and system capacity, help reduce flooding events, and support future growth in the downtown area.

The City is working with a design build team of James W. Fowler Co. and Kennedy/Jenks Consultants to design and construct this new stormwater pipeline. The project has completed Stage 1 - Design Phase.  Stage 2 - Construction is planned to start October 2021.  See the map for the project area.

We will share more information about construction methods and sequencing as design progresses.


Project Goals

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

  • Provide surface water 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.

Construction Update (10/12/21)

The City of Tacoma is installing a large, 72-inch diameter stormwater interceptor pipe and a new stormwater outfall into Thea Foss Waterway, starting as early as October 20, 2021. This project will enable the City of Tacoma to improve existing storm sewer and system capacity, help reduce flooding events, and support sustainable future growth in the downtown area. This work will be complete by fall 2022.



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. 


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. 

Open Cut Construction Image


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 trenchless construction

Construction Impacts

Construction will start in late October 2021 and take approximately one year to complete. During construction you can expect:

  • Weekday work hours, 7 a.m. – 5:30 p.m. Minimal night and weekend work.
  • Construction noise, dirt, and vibrations
  • Lane restrictions
  • Full street closures. Local access will be maintained.
  • Pedestrian detours
  • Parking and delivery restrictions


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.


Contact Information

For additional information, call the project hotline at (253) 279-5509 or email the project team.