The immense flowing rivers of South Asia ─ from the sprawling Indus system in the West to the volatile Irrawaddy in the East ─ were turned into modern rivers through the course of British colonial rule in the nineteenth century. This 'great hydraulic transition', I argue, was philosophically premised on the need to separate land and water ⎯  as two distinct non-overlapping natural domains. A  transition effected, in the main, by the interventions of colonial engineering  with which rivers were quantified as units of flow, disclosed by comprehensive control  and harnessed with weirs, embankments and dams. The introduction of colonial hydraulic infrastructure, in essence, was to sustain land as legal claim and to be imagined as permanent ownership, while river flows were recast as resource.

As the quest for large dams and megawatts continues to convulse the political and ecological worlds of South Asia (and many other parts of the world), subversive histories about colonial engineering and river control, I argue, will be critical to how we re-imagine other social possibilities.