Reciprocity in practice: the hydropolitics of equitable and reasonable utilization in the Lancang-Mekong basin

Equitable and reasonable utilization (ERU), the cornerstone of international water law, recognizes the rights of states to utilize shared water resources. However, there is ambiguity in ERU's application, and upstream states often perceive it as against their interests. Recent research highlights the important role reciprocity plays in international water law, yet how reciprocity is practiced in transboundary water governance remains poorly understood. Combining literature on international law, hydropolitics and international relations, this article conceptualizes 'reciprocity in practice' for international watercourses as interconnected legal, social and political processes by which state and non-state actors negotiate ERU and distribute benefits and harms. We pay particular attention to power relations and perceptions of fairness that influence the form and (dis)continuity of reciprocity. We demonstrate our approach through an analysis of evolving legal regimes and issues of navigation, hydropower, flood and drought management, and economic regionalization in the Lancang-Mekong basin, focusing on relations between China and downstream states. We demonstrate how multiple forms of reciprocity occur simultaneously across issues that are often analyzed individually, complicating common narratives of China's unilateralism. We show, however, that practiced positive reciprocity is weak and exclusive, generating distrust and resistance from those excluded or who experience harms. Overall, we suggest that processes of 'reciprocity in practice' are at the heart of meaningful negotiation, institutionalization and practice of ERU, and that, as a model of water allocation, ERU should be contextualized to wider process of allocation of benefits and harms that include but go beyond water, and in which power relations fundamentally matter.