430 Pipeline Improvement Project

Project description

Construction work on pipeline improvements

The 430 Pipeline Improvement Phase 2 project will repair and upgrade portions of the large steel water 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.

The first phase of the project (“Phase 1”) included water system upgrades, the installation of 14 new pipe access points, and rehabilitation of 30% of the pipeline. Phase 2 will continue the work started in Phase 1 by rehabilitating the remaining 70% of the pipeline. The majority of the work for Phase 2 will be underground; however, crews will be installing new pipeline access points and staging construction equipment at the road surface.

Location

Construction for the 430 Pipeline Improvement Phase 2 project will occur inside of the underground pipe and requires staging equipment above ground at multiple work sites.

Work will take place at several locations along the pipe alignment in the Maple Leaf, Roosevelt, University District, Portage Bay, and Capitol Hill neighborhoods. View the pipe alignment map for the approximate location of the underground pipe.

What's happening now?

Construction for the 430 Pipeline Improvement Phase 2 project began in mid-January 2025. SPU crews are currently performing underground utility work along Federal Avenue between SR 520 and Volunteer Park. Crews are also working at the gate house located in Maple Leaf Reservoir Park. The project team will continue to update the project website and mail construction notices to adjacent neighbors as crews move between sites. Water service will be maintained throughout construction.

Community benefits

The 430 Pipeline Improvement Project is a part of the region’s drinking water system. Phase 2 of the project will:

  • Increase the resiliency and reliability of Seattle’s drinking water system
  • Protect the pipeline against corrosion

Community engagement

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

Winter 2025 - fall 2026

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000
SPUCustomerService@seattle.gov

Newsletter Updates

Subscribe

Sign up for the latest updates from Public Utilities

Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.