This paper firstly presents a brief overview of the complex environment of the Southern African Development Community (SADC) region in the context of disaster risk reduction (DRR), analyzing characteristics of the major hazards and actors involved. Secondly, it argues that the SADC Water Division and International River Basin Organizations (RBOs) in Southern Africa can play a crucial role in DRR in the water sector, providing a platform where agreements on data and information sharing are reached, best practices are exchanged, policies harmonized, new collaboration mechanisms are discussed, and coordinated interventions are decided upon. Moreover, RBOs can facilitate the adoption of basin-wide Integrated Water Resource Management plans, building on the pillars of economic efficiency, social equity and environmental sustainability with the result of reducing hazards and increasing resilience. RBOs can represent the shared interests of riparian states from a basin perspective to other international actors. To achieve these goals, RBOs in Southern Africa face significant challenges: broadening stakeholder participation, gaining buy-in from Member States on their representation and facilitation of specific matters. Possible approaches to overcome these challenges will be suggested in this paper.