Water pollution has emerged as an area of concern in rapidly growing cities in India. With continued large investments in centralised waste water treatment systems, and a growing number of innovations in the decentralised treatment approaches, stormwater drainage networks are often overlooked as a potential locus of intervention. These networks, however, have the potential for focused intervention to improve surface and groundwater quality. This article dwells on a lab-tested, low-cost, and novel waste water management system called strategic in-stream treatment systems, which can be scaled up to existing and emerging cities in India.