The movement of the Hughli River in 1804-5 resulted in the deposition of alluvion along Calcutta’s river banks which unfolded as an ownership crisis for the East India Company. The Company responded by developing new legal categories and administrative language to manage these newly formed lands and thereby fashioning itself as a public agent of Calcutta’s land and landed property. Focusing on specific legal aspects of colonial hydrology that arose in the making of property in these amphibious spaces, the article argues that the soaking ecology of Bengal became a site for productive law-making by creating open-ended possibilities for taking land. It demonstrates how the Company used this new land formation to gradually institute a legal arc...