Water security is a key governance challenge especially in relation to transboundary rivers. While the literature elaborates on the water security concept, there is very little on how to operationalize it in the transboundary context. Hence, this paper addresses the question: How can the governance of transboundary rivers be operationalized to deal with national water security concerns? It uses a literature review and a case study focusing on dams in the Mekong tributaries, namely the Sesan, part of the 3S Basin, in Vietnam and Cambodia. The paper describes the damming process in the 3S Basin and how it threatens water security for downstream states in terms of securing the flow, volume, quality, space, and the temporal variations of the rivers and the livelihoods of river dependent communities. It examines how the Mekong River Commission (MRC) members address these issues, balance their interests and secure the free flow of the Mekong River and its tributaries. It concludes that the MRC Agreement of 1995 is an inadequate mechanism to regulate the developments of hydrological infrastructure on the shared international tributaries, and that further operationalization of the concept of water security is necessary to enable the improvement of existing cooperative regulations and mechanisms.
River Levels Derived with CryoSat-2 SAR Data Classification—A Case Study in the Mekong River Basin