A Mumbai-based man, Subhajit Mukherjee, has developed a low-cost rainwater harvesting system priced at ₹2,500. The setup utilises PVC pipes and a perforated barrel placed in underground pit to channel rainwater from rooftops, aiding in groundwater recharge. Mukherjee, founder of Mission Green Mumbai, has implemented this system in schools and housing societies, benefiting thousands of residents.