This project examines the social and environmental consequences of transnational dams in the Alps since 1870. It traces the social debates sparked by floods in mountain valleys and the fate of the towns and mountain communities hit by them. In parallel, it analyses the ecological consequences of dams built in the Alps. To this intent, the project takes into consideration both the transnational and environmental history of the areas involved to provide a big-picture view of Europe’s ‘water towers’ as a macro region inside of which individual alpine countries play a definitive role. Many dams were built not only with the assistance of international energy corporations. But countries too embark on dam constructions in natural water courses in cross-border areas where there are consequences for neighbouring nations. This research project will provide a historical overview of the local socio-ecological costs of hydraulic constructions in the Alps and cast a spotlight on the transnational networks involved.