Compound Environmental Operating Stress and Cyber-Induced Pump Disruption in Water Distribution Networks: Matched Hydraulic Impacts, Service Continuity, and Sustained Recovery

Digitally controlled water distribution systems must maintain service during disruptions, yet restoring water delivery does not necessarily ensure hydraulic recovery. This study evaluates cyber-induced pump outages under hypothetical environmental operating stress using two EPANET benchmark networks (Net1 and Net3) simulated with the Water Network Tool for Resilience. The experimental design comprises 288 simulation records (240 distinct configurations), including 192 verified attack scenarios, with four- and twelve-hour outages, six hydraulic configurations, and four mitigation strategies. All attack scenarios satisfied pump-shutdown verification and pre-attack hydraulic-equivalence criteria. Twelve-hour outages produced an average of 404.96 m$^3$ of unmet demand in Net1, while Net3 maintained full modeled demand delivery despite pressure deviations. Sustained pressure recovery occurred in 103 of 192 scenarios, with 65 exhibiting subsequent relapse, whereas all scenarios satisfied the post-outage water-service recovery criterion. Combined mitigation eliminated unmet demand in evaluated Net1 scenarios, while outage shortening achieved the highest sustained-pressure-recovery count. These findings highlight network-dependent resilience and the distinction between service restoration and hydraulic recovery. Environmental stress scenarios represent sensitivity assumptions rather than empirically calibrated climate impacts.