Many new dam projects are presently being put forward, revealing both the comeback of large hydraulic infrastructure and the resilience of the modern ontology of water. To contribute to the understanding of modern water’s perpetuation, this paper takes a step back in time and looks at the cases of two dam projects which were cancelled during the 1980s due to environmental protests: the Loyettes Dam on the Rhône River in France and the Gordon-below-Franklin Dam on the Gordon River in Tasmania, Australia. Previous studies in the political ecology of water have paid attention to opposing discourses, representations, imaginaries and, more recently, to ontologies when considering conflicts involving modern water. This paper further explores the contestation of modern water that occurred in the late twentieth century. It focuses not only on pre-existing ontologies of water but also on the production of water ontologies during and after sociotechnical controversies. It does so by 1) asking how modern water seeks to maintain itself, and 2) questioning the rise of alternative water ontologies. The discussion identifies different water ontologies which vary in a continuum from nonmodern to modern; it also connects them with ways of being with the environment in general. The study concludes that while controversies may result in the transformation of planning practices and changes in water ontologies, the hegemony of modern water is only partially challenged by successful anti-dam movements.