Perspectives and Prospects for International Water Law in the ASEAN Region: Is There an ASEAN Way to Transboundary Water Cooperation Under International Law?

Abstract

Around the world there are over 300 transboundary watercourses and around 500 transboundary groundwater bodies shared by two or more States. The Association of Southeast Asian Nations (ASEAN) region contains forty-one transboundary surface and groundwater bodies shared between ten ASEAN States and the five non-ASEAN States at its periphery. As transboundary water resources they are governed under international law found in a series of layers across a spectrum of bindingness (customary international law, global–regional–multilateral–bilateral agreements and non-binding instruments). Through an analysis of the international law relevant to the governance of transboundary water resources in the region, this study seeks to explore the ASEAN approach to transboundary water governance under international law. While this analysis finds that there is no uniform practice across the region, the paper concludes with possible paths forward for the legalization of transboundary water cooperation.