Modeling and Analysis Support On-Call Services
Client: Seattle Public Utilities
Year Completed: On-going
To provide on-call modeling support services for SPU’s drainage, wastewater, and combined systems.
Model development, refinements, calibration and validation
Basin and project level modeling of options, analysis of design alternatives
Completion of system models (drainage and sewer) under a single modeling platform
System Wide Sewer System Model Extension and Calibration
Merged all previously developed models into a system wide set of models using SWMM5 modeling platform. All sanitary sewers 8-inch and larger within SPU’s service area were included in the model. Additionally, King County’s interceptors and associated facilities that serve the SPU’s collection system were also included in this model. Over 38,000 pipes for a combined length of over 1,500 miles were modeled using 13 regional basins that are interconnected and primarily discharge to King County’s West Point Treatment Plant. Models were calibrated at 52 major locations using flow meter and SCADA data from 2010 to 2012. Previously calibrated models within the collection system were included into the Regional Models unchanged.
Drainage Basin Model Calibration
Calibrated previously developed SWMM5 models in Pipers Creek, North Beach/Blue Ridge, Ballard, Longfellow Creek, Magnolia, Interbay, and Lander basins. Approximately 7,900 acres of tributary area was calibrated at 33 locations using metered data from at least one wet season.
Joint Operations & System Optimization Plan (Montlake Regulator):
Conducted modeling analysis to determine the feasibility of modifications to the outlet hydraulics and operational strategies of SPU’s existing Washington Park Stormwater Storage Facility (2.2 Mgal) and its existing pump stations to reduce the CSO event volumes at the regulator and at SPU’s existing CSS outfalls. The Montlake Regulator Basin is approximately 2,900 acres and includes Madison Valley, Leschi, Madison Park, and portions of Montlake basins. The results of this modeling effort showed that proposed automated gates recommended and simulated optimization strategies increased the use of the Washington Park Tank while reducing overflows at the Montlake Regulator for a variety of events.