REPAIR SEQUENCE AND RECOVERY TIME IN WATER DISTRIBUTION NETWORK RESILIENCY

Abstract

Recent disasters highlighted that Water Distribution Systems (WDS) suffered greatly duringseismic events. But people cannot afford to have extended water service interruption as it is essential fordrinking, sanitation, and health. Thus, it is imperative that WDS provides adequate resistance to extreme events.And in the event of failure, it must recover back its functionality within short period. Resilience-basedengineering ensures that infrastructures be robust to adequately resist seismic events and recover from failurefast. It also requires to have resources and redundant systems. This implies that WDS must satisfy resiliencyrequirements for it to function satisfactorily during and after seismic events. This study quantifies the resiliencyof La Trinidad Water District (LTWD) through measuring the impacts of restoration sequences to recoveryduration and knowing which sequence satisfies resiliency. LTWD, in Benguet, Philippines, is at risk toearthquake due to geologic and geographic setting, thus, it must be “resilient”. In this study, restorationstrategies were conducted using constrained spanning trees to determine the most efficient networkconnectivity. Horn’s algorithm was applied to find the most efficient repair sequence. Results showed thatrestoration sequence is directly related to rapidity of resiliency. The shortest restoration resulted to a fasterrecovery to return back to its pre-event system functionality. For LTWD, restoration will take 8.62 days forfull recovery.