India is gifted with a bouquet of 20 perennial and non-perennial river systems, with several tributaries. Our rivers, mostly originating from the Himalayas, the Chhotanagpur Plateau and the Western Ghats, receive a significant run-off, from glaciers and precipitation, accumulating an average annual flow of 1,953km3, while replenishing groundwater resources of around 432km3. This enables the formation of a perennial utilisable water resource, one expressed in surface water (690km3) and ground water (396km3). In particular, Himalayan snow and ice melt offers a significant boon, with water yield in such river basins nearly double that of the peninsular rivers. Groundwater, wherever available, remains a significant source of water, particularly for domestic consumption, contributing 80 per cent of the household requirement and over half of the irrigation requirement.
India’s rivers undergo a series of changes across their route and through seasons—turning into a slack pool during winter; raging as torrents during the monsoon, awing us with its destructive potential. While rivers are often described in a feminine sense, as nadi, beautifully coursing across Jambudvip, as dividers of solid land, they can also be dangerous. After all, the Ganga descended from heaven, bringing with it fertile soil for good crops, but also destruction in its wake. Sustainably managing such mercurial rivers to meet the challenges of rural India can hence be a hard task.
To combat this risk, and to provide irrigation to millions of marginal farmers, modern India has sought to build dams. Starting from 1947, when there were just 300 large dams across India, the government has built around 4,900, with the majority built between 1971 and 1989. The primary purpose of these dams has been to further irrigation, in addition to control floods, ensure water supply and generate hydroelectricity. Large dams, termed as “temples of modern India” by Jawaharlal Nehru in 1955, were encouraged post-independence to jumpstart industrialisation and establish a scientific outlook