New Water Supply Line Added to 2025-2030 Capital Improvement Plan

At the October 1, 2024 City Council Meeting, City staff presented recommended actions to improve resiliency of the permanent water transmission line from Seattle Public Utilities (see AB 6530). The 24-inch concrete cylinder water transmission line located in the SE 40th Street right-of-way was constructed in 1956 and has required several leak repairs over the years. The City and Shorewood Apartments are the two wholesale customers served by SPU’s water transmission line. Given the overwhelming cost responsibility held by the City, and the importance of this water transmission line, the City began exploring options to replace this segment of pipe with a stronger, earthquake resistant transmission line in an alternative alignment.

This City considered several options, details of which can be viewed here. After careful consideration, the City Council approved the design and construction of a new 24-inch earth-quake resistant supply line to replace the existing SPU supply line. The location of the new 24-inch supply line corresponds with several previously planned projects. To reduce construction costs, schedule, and impacts, this project was combined with these previously planned projects.

City Council voted to direct staff to include the design and construction of a new 24-inch transmission line in the 2025- 2030 Capital Improvement Plan. City staff will negotiate a preferred pipeline alignment and ownership from Seattle Public Utilities and identify long-term solutions to serve the Shorewood Apartments.