By all standards, water is today and tomorrow's most coveted resource. Although it has often been a vector of cooperation among multiple actors, observers generally agree that environmental conflicts around water management are likely to harden and entail severe risks of social and political unrest in overpopulated cities, both in the South and in the North. Worrying trends include recurring droughts and flooding, increasing volatility of resource availability, the melting of glaciers, and resource contamination due to industrial pollution, modern agricultural practices and lack of adequate sanitation. However, the specific way whereby mounting environmental challenges reinforces and/or modify the traditional dynamics of water conflicts has received remarkably scant attention. It is partly due to a technical bias that has devoted studies at identifying best practices and efforts at joint regulation by stakeholders rather than recognizing the pervasiveness of tensions, however evolving these tensions may be. By contrast, the BLUEGRASS project sets out to understand the evolving logics of water conflicts in front of new environmental challenges, rising from the encounter of two processes: climate change and urban dynamics, that contribute to produce freshwater insecurity. The will do so, in particular, by analyzing the vagaries of the exportation of the two-dimensional “French model” (i.e. a focus on management at the level of the water catchment area, and the promotion of the private sector to address environmental challenges) in the Americas. The research will focus on the way environmental problems are socially perceived and constructed, but also strategically appropriated and used by a wide range of actors. Case studies will include cities and their surrounding rural region in the West of the United States, Mexico, Colombia, Bolivia and Brazil. Brazil will especially be devoted a lot of attention, as the project fits within the framework of a bilateral ANR-FAPESP agreement. Theoretically and methodologically speaking, this comparative with a small number of cases project seeks to highlight the interplay between multi-level coalitions, by analyzing both the fabrication of a global model, different national appropriations of and reactions to this model, and the way local conflicts play out. It also sets out to pinpoint the interactions between rural and urban issues, and to document the evolving tensions between the city centers and their peripheries in various contexts.