A critical overview of transboundary aquifers shared by South Africa

Transboundary groundwater commonly implies a body of groundwater intersected by a political border with the attendant potential threat of dispute over a shared resource. This definition is inadequate in many parts of southern Africa. Approximately 96% of South Africa’s borders are underlain by low-yielding aquifers and, coupled with a low demand for water attendant on low population density, the risk of over-pumping or pollution leading to dispute is low, and a modified understanding is required. Examples of transboundary aquifers are used to illustrate implications for policy and management of southern African transboundary groundwater resources, where transmissivities are low and, less commonly, where over-pumping may indeed be a problem. The general lack of technical cooperation, data sharing, training and research between the riparian states on hydrogeology hampers a mutual understanding of the resources. The concept of transboundary groundwater must necessarily include aquifers where little cross-border flow occurs, but where cross-border cooperation will help to ensure sustainable cooperative utilisation of shared aquifer resources. This is imperative if future disputes are to be averted. Agreement between scientists is a necessary precursor to broader transnational governance agreements in regard to shared water resources, and recent initiatives by the Orange-Senqu River Commission promise closer integration.