303 - Evaluating the Resilience of Hybrid Centralized and Decentralized Water Supply Systems

As urbanization accelerated and environmental challenges escalated, conventional centralized water supply systems have faced sustainability challenges from frequent droughts, climate change, energy security, water leaks, and aging infrastructure. In this regard, scientific communities have discussed that employing a decentralized water supply approach with local water sources (e.g., treated wastewater and harvested rainwater) can offer more sustainable water services from these circumstances. However, few efforts have been made to investigate the resilience of decentralized water supply systems or hybrid centralized and decentralized water supply systems against unexpected failure events. In this regard, this study evaluates the resilience of hybrid water supply systems to physical and operational failures. First, this study defined the configuration and operations of a hybrid water supply system and analyzed the hydraulic performance of the system under failure scenarios using a pressure-driven model of EPANET 2.2. The failure scenarios included pipe leakage/burst, cyber-physical attacks, and demand variation. Then, the resilience of the hybrid water supply system to the failure scenarios was evaluated using a functionality-based resilience measure. The results demonstrated that the hybrid water supply system produced the larger resilience effects to unexpected failure events, compared to the conventional, centralized water systems. The discussion on designing the operations of a resilient hybrid water supply system to failure events was provided based on the resilience evaluation results. The findings will suggest engineering insights into how to configure the operational tradeoffs between centralized and decentralized water systems to resiliently deal with unexpected failure events.