The Yamuna is one of India’s most sacred rivers. But on its 22-km stretch through Delhi, the Yamuna gets reduced to being a polluted drain. Four decades of efforts to restore the river have mostly ended in failure. Delhi, one of India’s richest cities, does to the Yamuna what Indian cities generally do to their rivers — which is to swamp them with wastes, diminish their natural flow, occupy precious floodplains and destroy wetlands and aquifers.

Rivers thrive much beyond their courses. To be in health and serve cities well, they need the freedom to flow. Those marshes, tanks, ponds, canals and water-filled layers underground all make up a river’s being. To take them away through urbanization is to suck the life out of a river.