Kleinschmidt Associates has secured a contract with Seattle Public Utilities (SPU) to deliver engineering and permitting services for the evaluation of options aimed at enhancing the South Fork Tolt Dam's spillway, situated to the east of Seattle, Washington, US.
The South Fork Tolt Project is jointly owned and operated by two arms of the City of Seattle: Seattle Public Utilities (SPU) and Seattle City Light (SCL). At present, this project serves as the primary drinking water source for approximately one-third of SPU's extensive customer base, totaling 1.5 million residents in the Seattle region. Additionally, it contributes hydropower generation, flood mitigation measures, and other essential functions. Recent assessments commissioned by the City have recommended a further in-depth analysis to explore potential operation and maintenance enhancements.
In response to these needs, SPU has appointed Kleinschmidt to spearhead these supplementary investigations and identify viable spillway improvement alternatives. The process will incorporate a multi-criteria analysis to narrow down initial options to a final selection. The evaluation criteria will encompass dam safety, the resilience of the water supply, and potential repercussions on the environment and local community. Advanced technological tools, including two physical hydraulic models and a computational fluid dynamics model, will be deployed to gain a comprehensive understanding of the spillway's hydraulic behavior.
“I am really excited about supporting SPU with this project.,” said Carl Mannheim, P.E., Project Manager and Principal Engineer at the Redmond, WA, office of Kleinschmidt. “Together with our local teaming partners Clarity Engineering, RIE Consultants, and Ott-Sakai, this project provides a great opportunity to use our local hydraulic structures, dam safety, and permitting expertise and experience to assist with an important local project.”
The South Fork Tolt Spillway Options Analysis Project commenced in January 2023 and is anticipated to conclude in early 2024.