<p>Urban centres across the globe are increasingly experiencing water scarcity and stress, primarily driven by rapid population growth, climate change, unsustainable resource exploitation, rising pollution levels, and accelerated urbanisation. The transformation of land use from non-urban to urban, coupled with demographic shifts, has significantly strained existing water supply infrastructure. Notably, the global water demand is escalating at approximately twice the population growth rate, exacerbating the pressure on water systems. This study proposes a comprehensive, integrated mathematical model to optimise three critical dimensions of urban water, i.e. supply system, planning, and resource management. The model’s objective is to concurrently enhance economic efficiency, equitable water allocation, and socio-environmental sustainability while minimising the overall cost of the water distribution network and reducing the incidence of pipeline failures or leakages. The model was applied to a case study of Ranchi, a rapidly urbanising city in eastern India. Data analysis and scenario generation were conducted using the Water Evaluation and Planning (WEAP) tool in conjunction with EPANET to simulate hydraulic parameters and assess network performance. Genetic algorithms were employed to identify Pareto-optimal solutions across multiple conflicting objectives. The model outputs were projected for 2037, aligned with the Ranchi Planning Area’s development zone. The simulation results offer valuable insights into optimal sectoral water allocation strategies, appropriate pipe diameter specifications, and quantified environmental flow requirements, supporting informed decision-making for sustainable urban water resource management.</p>