Identifying transboundary aquifers in need of international resource management in the Southern African Development Community region

Transboundary aquifer (TBA) management, in part, seeks to mitigate degradation of groundwater resources caused either by an imbalance of abstraction between countries or by cross-border pollution. Fourteen potential TBAs were identified within a hydrogeological mapping programme based on simple hydrogeological selection criteria for the Southern African Development Community (SADC) region. These have been reassessed against a set of data associated with five categories: (1) groundwater flow and vulnerability (which is perceived as the over-arching influence on the activity level of each TBA), (2) knowledge and understanding, (3) governance capability, (4) socio-economic/water-demand factors, and (5) environmental issues. These assessments enable the TBAs to be classified according to their need for cross-border co-operation and management. The study shows that only two of the 14 TBAs have potential to be the cause of tension between neighbouring states, while nine are potentially troublesome and three are unlikely to become problematic even in the future. The classification highlights the need to focus on data gathering to enable improved understanding of the TBAs that could potentially become troublesome in the future due to, for example, change in demographics and climate

Aquifers Shared Between Mexico and the United States: Management Perspectives and Their Transboundary Nature

Totally 36 aquifers have been identified along the Mexico-U.S. border. Of these, only 16 have adequate data to provide a reasonable level of confidence to categorize them as transboundary. Limited and/or contrasting data over the other aquifers in the region reflects the void in transboundary groundwater management and assessment mechanisms throughout much of the Mexico-U.S. border. This paper identifies management mechanisms, structures, and institutional prioritization related to transboundary aquifers shared between Mexico and the United States. It also evaluates the differences in the transboundary nature of these aquifers, and how their combined hydrological and geographical considerations interrelate with local and regional social, economic, political, and even scale dimensions to create complex management challenges