Tarun Bharat Sangh of Alwar is well-known for its work on reviving traditions of waterharvesting. But few know about the economic advantages of the water harvesting structures it has built and promoted in villages. For every Rs 100 invested in small earthen check-dams known as johads, the economic production in villages has risen by Rs 400. And all this prosperity has come through the use of only three per cent of the total rainwater. Five rivers now flow perennially, a result of the 20 per cent additional groundwater recharge. Richard Mahapatra documents the reasons behind this success