Groundwater has been central to the Green Revolution and to urban development. This essay explores the praxis and politics of knowledge about groundwater in the mid-twentieth-century India and shows how this knowledge became an important but contested concern.

The Geological Survey of India (GSI) became increasingly involved in advising on groundwater through the interwar, wartime and Nehruvian eras. Groundwater science was one of the many arenas in India that received substantial American aid in the postcolonial period and this essay explores that shift from British to American expertise. The American-aided All India Groundwater Exploration Project was a massive engineering exercise, presenting new kinds of challenges for the GSI; its impact lies as much in training skilled drillers who would go on to drive India’s Green Revolution as it lay in producing geological knowledge.

Water-diviners continued to be employed by interwar and postcolonial governments. Though the practice received sharp criticism from colonial Indian politicians, it barely received political comment in postcolonial India, even as Nehru himself was an enthusiast of a famed diviner. Divining also received sharp criticism from the GSI, but one reason for its prevalence was the inability of groundwater science to offer the firm answers demanded by engineers and politicians.