This paper presents a systematic, global assessment of transboundary watersheds that identifies regions more likely to experience hydro-political tensions over the next decade and beyond based upon environmental, political, and economic indicators. This study examines the stresses inherent in development and the mitigating impact of institutions and maps the risk of potential hydro-political tensions that exist where basins may be ill-equipped to deal with transboundary disputes triggered by the construction of new dams and diversions.