This research has been supported by a grant from Royal Norwegian Embassy (RNE), International Development Research Centre (IDRC) of Canada, Arghyam Foundation, and Ashoka Trust for Research in Ecology and the Environment (ATREE). The authors would also like to thank Chandan K Gowda, Praveen Kumar, and Sowmya Murugan of ATREE for their help in collecting primary data on water quality. 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.