Telling an environmental history of Viennas urban waters, this paper advocates the compound study of the evolution of fluvial and urban form. It traces the structural permanence of diverse types of running waters in a period of massive urban transformation from early modern times to present. The focus on the material effects, side-effects and afterlives of socio-natural processes offers novel perspectives to the reconstruction of city development. The featured cases show that long-term studies are vital in understanding the genesis of urban water bodies and urban form as a product of socio-natural processes. They inform us about the inertia of arrangements and the unforeseen perpetuation of site-specific effects of interventions. Societal interaction with natural elements such as Viennas waters, we conclude, reverberates in the material and immaterial realm alike.