Rapid response and impact assessment of water quality incidents in urban water distribution systems using forensic techniques

Water quality incidents in drinking water distribution networks require rapid operational decision-making to limit contaminant propagation and service disruption. This study proposes a hydraulically informed operational shutdown framework that integrates incident occurrence time and utility response time to support real-time decision-making during water quality emergencies. Network-based forensic analysis is applied to estimate contaminant travel times under variable demand conditions and to identify valve isolation actions that are feasible under realistic field constraints. To translate analytical results into actionable operations, the concept of Possible Operated Segments (POS) is introduced, defining the smallest isolation units that can be practically actuated during emergency response. In addition, a Cause–Impact–Duration (CID) analysis is employed to quantify location-specific impacts and the time-dependent escalation of service disruption. By jointly considering hydraulic propagation dynamics and operational feasibility, the proposed framework enables utilities to evaluate when and where intervention is most effective. Application to representative turbidity scenarios demonstrates that the framework provides clear guidance for prioritizing valve operations, containing incident impacts, and improving response timeliness, highlighting its potential as a practical decision-support tool for enhancing emergency response capability and operational resilience in drinking water distribution systems.