The potential benefits that can be derived from international water cooperation are often limited by separate management of ground and surface water. Globally, over 300 treaties have been crafted for freshwater river basins while dedicated groundwater treaties are still less than 10. Similarly, numerous river basin organisations (RBOs) exist, which are primarily oriented toward surface water management. However, joint groundwater institutions are scant. Failure to apply greater focus to groundwater – and more importantly, integrated approaches to surface and groundwater – may mask key opportunities for improving the management of water across borders.
Surface water and groundwater systems are connected in most landscapes. The interconnectedness between and among water sources calls for conjunctive management of those sources to encourage their optimal use. Conjunctive management refers to the simultaneous management of ground and surface water resources, to achieve security of water supply and environmental sustainability.
The conjunctive management of water resources can bring a range of benefits including contribution to vulnerability reduction, climate resilience and protection of aquatic and terrestrial life, as well as optimising water productivity and environmental sustainability. This is more so the case in shared river-aquifer systems where increasing and often conflicting water demand has to be addressed. Within SADC, where more than 15 river basins are shared, and 25 shared aquifers have been identified to date, primarily in arid and semi-arid and climate-sensitive regions, conjunctive management of shared water systems is even more urgent. Good progress is seen on developing joint agreements and institutions related to transboundary river basins and increasingly also on aquifers. However, little coordination of the work on surface and groundwater exists to date. Yet, up to 60% of the populations in this region is reliant on groundwater, while focus of international work has traditionally been on surface water.
As part of fulfilling the vision of the Southern Africa Development Community’s Groundwater Management Institute (SADC-GMI) to ensure the equitable and sustainable use and protection of groundwater in the SADC region, important work is being undertaken on shared aquifers. The lessons learnt from the ongoing work related to the Transboundary Aquifers (TBA) of Ramotswa (Botswana and South Africa) and Stampriet (Botswana, Namibia and South Africa) inspired the decision to broaden research and stakeholder engagement on the management of TBAs in the region. As such, research into shared groundwater aquifers is growing with the aim of assisting RBOs and other institutions in integrating groundwater and surface water management. The Shire Basin (Malawi, Mozambique) has been identified as an important pilot case to develop comprehensive assessment tools and joint stakeholder processes, which will inform conjunctive transboundary water management in the basin and more broadly in the region.
