Bitter Lake Reservoir Improvements
Seattle Public Utilities (SPU) is addressing a problem shared by many mature drinking water systems: aging storage infrastructure that must meet modern drinking water standards as population growth places greater demand on the system. Replacing the decades-old Bitter Lake Reservoir with a new, seismically resilient reservoir, SPU is strengthening reliability across the North Seattle distribution system. The project also creates an opportunity to return a portion of the site to public use through community open space improvements.
Following a comprehensive options analysis in 2020, Consor led design of a new 21 million gallon, partially buried AWWA D110 Type I prestressed concrete tank. Delivery required close coordination among SPU, Seattle Parks and Recreation (SPR), the Office of Arts and Culture, and the Department of Neighborhoods, with a large multidisciplinary design team supporting reservoir design, site improvements, permitting, and public open space planning. Without a conventional storm sewer connection available to the site following improvements, the 14-acre site also needed stormwater treatment, detention, and underground injection wells that support construction and long-term operations without costly off-site upgrades.
The team designed recreational site access and right-of-way improvements associated with the reservoir improvements, including half-street roadway reconstruction on neighboring streets, ADA-compliant sidewalks, and an accessible concrete trail coordinated with the Seattle Department of Transportation. Feedback from nearby residents that was gathered through an open house, surveys, focus groups, and pop-up outreach at gathering places informed future park and open space improvements.
When complete, the project will provide North Seattle with a modern, seismically resilient drinking water facility and several acres of new community open space. Construction is anticipated to be finished in 2029-2030, with open space improvements to be completed by SPR following construction of the reservoir improvements.
