Comprehensive evaluation of SPU’s water system to plan for future improvements.
Studying the system. To plan for future capital improvements and mitigate water system failures for 1.8M residents, Seattle Public Utilities (SPU) needed a peer review and seismic evaluation of its water system. Reid Middleton led a multidiscipline team in the structural seismic evaluation of 26 buildings, 12 concrete tanks, and six steel tanks. The project also included peer review of work by previous consultants, including review of site-specific seismic criteria. Facilities were evaluated using ASCE 41 Tier 1 procedures and AWWA building code documents. The study considered three earthquake levels: 1.) International Building Code/ASCE 7 design earthquake 2.) M9.0 Cascadia Subduction Zone scenario earthquake 3.) M7.0 Seattle Fault scenario earthquake. SPU will use the results of the study to inform their future capital improvements programs and assist in the development of level-of-service goals for the water system post-earthquake.