A circular economy framework to mitigate water scarcity and river pollution in Delhi, India

Delhi faces a drinking water deficit of nearly 2000 Million Liters per Day (MLD) driven by rapid population growth, climate variability, and dependence on interstate sources. This study proposes a phased, circular economy-based roadmap to achieve water self-reliance by 2045. Using official datasets, field inspections, consultations, and scenario modelling, both conventional and non-conventional resources are quantified. Current filtered water supply from surface and groundwater is 4540 MLD against demand of 6540 MLD. Under projected population of 54.4 million by 2045, demand could rise to 14,797 MLD at the DJB norm or 10,880 MLD at the CPHEEO norm. Integrated measures such as wastewater reuse, NRW reduction, rainwater harvesting, groundwater recharge, and related interventions could raise total supply to about 14,928 MLD. Sensitivity analysis identifies population growth, NRW reduction, and reuse adoption as the most influential factors. Monte Carlo analysis shows a 90% confidence range from a deficit of 1200 MLD to a surplus of 2500 MLD. The results suggest that combined legal, technical, and behavioral measures can sharply reduce water stress and pollution, but full self-reliance will depend on strong implementation and favorable demographic trends.