This article examines the transnational dimensions of the European Union’s Water Framework Directive (wfd). Given that 60% of the waters covered by the wfd are transboundary, effective management requires transcending traditional legal frameworks of the nation-state. Accordingly, regulations for surface water and groundwater challenge the conventional binary division between national and transnational law. As water moves across borders, decision-making in one nation incorporates external elements into the policy processes of other nations sharing the water. The aim of this paper is to illustrate the transnational elements within the wfd and to present two cases where external factors transcend national borders.