Seattle to replace 21-million-gallon Bitter Lake reservoir with buried system
(UI) — Seattle Public Utilities (SPU) is replacing the 21-million-gallon Bitter Lake reservoir with a partially buried structure designed to improve long-term water quality and reliability.
The new facility will maintain the same storage capacity as the current open-air reservoir but provide greater protection from sunlight, dirt, and debris. By enclosing the system, SPU says the project will help preserve drinking water service for years to come.
The 13-acre site sits near Linden Avenue North and North 143rd Street. Design work is underway, with the project expected to reach the 90% completion milestone in fall 2024. Construction will follow, and SPU anticipates completing the project in spring 2026.
Much of the new underground distribution lines will be installed using horizontal directional drilling (HDD) to minimize disruption in areas outside of the roadway. Trenching will be used in street sections where crews need to locate or avoid existing utilities.
The project is part of SPU’s regional drinking water system and is intended to modernize aging infrastructure while reducing risks associated with exposed reservoirs.
Related News
From Archive
- Inside Sempra’s 72-mile pipeline with 18 major trenchless crossings
- Trump vetoes bill to finish $1.3 billion Colorado water pipeline
- PHMSA warns of heat risks in aging plastic gas distribution pipelines following deadly Pennsylvania explosion
- Infrastructure failure releases 100,000 gallons of wastewater in Houston; repairs ongoing
- OSHA seeks $1.2 million fine after fatal trench collapse in Connecticut
- Worm-like robot burrows underground to cut power line installation costs
- First tunnel boring machines complete testing for Hudson Tunnel Project
- Infrastructure failure releases 100,000 gallons of wastewater in Houston; repairs ongoing
- Construction jobs stumble into 2026 after weak year
- NWPX grows water infrastructure portfolio with Colorado precast facility

Comments