This chapter historically traces the degradation of Kolkata’s canal network by contextualizing it within the contemporary research on urban rivers, where water historians and political ecologists discuss how water bodies and tracts have been “thoroughly conquered” and “denatured” (Castonguay and Evenden 2012, p. 2). However, it rejects the linear explanation of this disruption portrayed in scientific literature and media reports which consider the colonial period as the “golden era” and the post-independence period as the stage dotted with bureaucratic reluctance, civic indifference, and overall apathy and lack of awareness with regard to protecting these canals. Shedding light on a succession of technologies, from inland boat traffic to steam navigation to the railways, this chapter illustrates how Kolkata’s canal network succumbed under the pressure of emerging networked infrastructures (like railways) which appeared more lucrative, promising huge investment returns to the state. Reading “archival silence” (with declining availability of records on the canal trade and investments since the early 20th century) as an indicator of decreasing colonial enthusiasm for the canal network as arteries of trade, the chapter also explores debates and discussions among proponents and opponents within the government and conflicts of interests among municipal officials and the state regarding the functioning of the canal system as a navigation network or a receptacle of the city’s wastewater. It ends with a discussion of the social and ecological costs of this disruption, complicating the mainstream “development” and “encroachment” narratives of contemporary times.