Across South Asia, a vast landscape of growing towns forms the connective tissue between rural hinterlands and metropolitan hubs. These emerging urban centers, often classified as small and medium towns, are where much of the region’s urban future is unfolding. The Following the Flows study, led by BORDA South Asia, examines how water and sanitation systems are shaped and function in such emerging urban centres. Rather than an infrastructure audit, it explores lived realities, mapping the connections, gaps, and everyday practices that define services. Drawing on in-depth interviews with municipal and state officials, water and sanitation experts, GIS mapping, spatial observations, and secondary data from urban local bodies, the study traces water’s journey from source to distribution, collection, treatment, and reuse, supplemented by stories and profile mapping that reveal the layered technical, institutional, and behavioural dynamics of service delivery. Covering emerging urban centres in the hills of Himachal Pradesh, Ladakh, and Nepal; coastal Kerala; Karnataka’s peri-urban belts; and deltaic Bangladesh, the study makes visible where breakdowns occur and why, creating a foundation for governments, development partners, and local institutions to design context-specific, loop-closing, and climate-resilient solutions, ensuring these centres not only grow, but do so sustainably, equitably, and with water security at their core.