Water outage predictions for natural hazards using synthetic water distribution systems

Hazards can impact water systems, leading to water outages that result in economic, environmental, and societal losses. Modeling a system's behavior helps develop short-term restoration strategies and long-term resilience planning. However, data on the topology and operational characteristics of real water systems are often unavailable outside of the utility operating the system, limiting the ability of others depending on the system to understand its vulnerability and resilience. We address this limitation by developing an algorithm that generates a synthetic water distribution system using only publicly available data. Our approach provides hydraulic information at the building level to support infrastructure resilience assessments. We validated our model by comparing the network topologic and hydraulic properties with data from the real water system of Ann Arbor, Michigan. Our synthetic model results indicate that 95% of the simulated building-level pressures were within <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mo>±</mml:mo> <mml:mspace></mml:mspace> <mml:mn>25</mml:mn></mml:mrow> <mml:annotation>$ \pm \;25$</mml:annotation></mml:semantics> </mml:math> PSI of the hydraulic model data from the existing system. To demonstrate an application of our model, we simulated water outages at the building level using hazard loading and fragility functions corresponding to an earthquake scenario.