430 Pipeline Improvement Project

Project Description

Construction work on pipeline improvements

The 430 Pipeline Improvement project will repair and upgrade portions of the large 42-inch diameter steel pipeline that runs four miles from Volunteer Park to Maple Leaf Reservoir in Seattle. The pipeline was built in the early 1900s and is part of the region’s drinking water system.

Location

Construction for the 430 Pipeline Improvement project occurs inside of the underground pipe and above ground at multiple worksites (about 12) in the Maple Leaf, Ravenna, University District, Eastlake, and Capitol Hill neighborhoods.

What's Happening Now?

November 2, 2022 Update:

Contracting crews continue to perform construction activities as a part of the 430 Pipeline Improvement project. This work is taking place in several neighborhoods in North Seattle:

In the University District: work will periodically occur at these locations:

  • NE 56th and 12th Ave NE
  • NE 52nd and 12th Ave NE
  • NE 47th and 12th Ave NE 
  • NE 43rd and 7th Ave NE
  • NE Northlake Wy and 12th Ave NE
  • Harvard Ave E between Eastlake Ave E and Franklin Ave E
  • Broadway E. between E Shelby St and E Hamlin St.

At each site, crews will work for several weeks to install an access hatch for the 430 Pipeline. They will return to the sites to permanently repave the street, restore any vegetation that was disturbed, and periodically access the pipeline for cleaning and repair work.

Roosevelt: In early November, crews will be working in the roadway on 12th Ave NE and NE 66th St to access a maintenance hole that connects to the 430 Pipeline.

Excavation work on 12th Ave NE near NE 75 St and 12th Ave NE near NE 62 St to install access hatches to the 430 Pipeline continues.

Crews will return to all sites periodically to access the pipeline for cleaning and repair work.

Ravenna: Paving to permanently restore the roadway at NE 54th St and Ravenna Ave NE is complete.

Maple Leaf: Site restoration work continues at the Maple Leaf Reservoir Park gate house, located at 1020 NE 82nd St. A fence in the grassy area directly outside of the gatehouse has been installed to allow crews and park users to remain safe during ongoing construction.

Capitol Hill: In early November, crews will begin working at Federal Ave E between E Lynn St and E Boston St. to install an access hatch for the 430 Pipeline. They will return to this site to permanently repave the street, restore any vegetation that was disturbed, and periodically access the pipeline for cleaning and repair work. Curb and street restoration work at Federal Ave E. and E. Miller Street, and Federal Ave E. between E. Boston St and E. Newton St, is complete. Crews will return later to complete vegetation restoration work.

Portage Bay: In early November, crews will begin working near 10th Ave E and E Roanoke Ave to install an access hatch for the 430 Pipeline.

Work on and below the University Bridge at Portage Bay Place East to remove debris and fill a utility chamber with concrete is complete. Crews will return to both Portage Bay sites periodically to access the pipeline for cleaning and repair work.

Community Benefits

The 430 Pipeline is a part of the region’s drinking water system. The improvement project will:

  • Increase the resiliency and reliability of Seattle’s drinking water system
  • Provide safer access to the pipeline
  • Protect against pipe erosion
  • Increase seismic resiliency
  • Improve fire suppression support
  • Add system redundancy
  • Provide greater pressure reducing and pressure relief capabilities

Community Engagement

SPU is committed to providing timely information and updates on project activities. Updates may be available in multiple formats, including: the website, emails, and/or mailings. If you are interested in receiving email updates, please subscribe to the project email list.