Transboundary water allocation in practice: global trends in international freshwater agreements

Water allocation – how water is divided between two or more entities – is addressed at many levels; however, research and policy tend to focus on the national level. At the international level, the focus is more on how actors negotiate, less on how water is physically divided. This paper fills this gap by focusing on how and why water is allocated between states. We develop the Typology for Transboundary Water Allocation to catalogue surface and groundwater allocation mechanisms within transboundary agreements, where mechanisms are separated into two components: a practical and a context component, or the how and why, respectively. Several conclusions are drawn: Over time, agreements with allocation mechanisms have increased. Groundwater-specific mechanisms and water allocated to environmental purposes have increased since the 1970s. With increasing challenges and demands on water resources, many transboundary basins still lack agreements with allocation mechanisms. Overall, the inclusion of allocation mechanisms has the potential to increase institutional capacity and, depending on their design, increase the flexibility to adapt to hydrological or socio-political change. However, the lack of allocation mechanisms or their design could contribute to potential environmental degradation, inequitable access, or conflict between states.