Water Demand Prediction and Optimal Redesign of Water Distribution Networks Considering Future Environmental Changes

Future demographic, industrial, and climate changes increase uncertainty in water distribution network operations. This study analyzes future water demand and hydraulic performance in Paju City from 2021 to 2050 and proposes an optimal network redesign strategy. Changes in unit water demand due to the increasing proportion of one- and two-person households and industrial demand growth were considered together with pipeline aging and extreme climate conditions. Scenario-based hydraulic analysis using EPANET was integrated with genetic algorithm-based optimization. The results show that total water demand will increase despite the eventual population decline, mainly due to increased unit demand. Extreme climate conditions had a greater impact on hydraulic performance than changes in demand or pipeline aging, resulting in 253 pressure-deficient nodes by 2050. Optimization showed that selective expansion of small- and medium-diameter pipes effectively mitigated pressure deficiencies. The proposed framework supports long-term water distribution network operation and redesign under future demographic, industrial, and climate changes.