Exploring Cooperative Transboundary River Management Strategies for the Eastern Nile Basin

A water resource modeling process is demonstrated to support multistakeholder negotiations over transboundary management of the Nile River. This process addresses the challenge of identifying management options of new hydraulic infrastructure that potentially affects downstream coriparian nations and how the management of existing infrastructure can be adapted. The method includes an exploration of potential management decisions using a multiobjective evolutionary algorithm, intertwined with an iterative process of formulating cooperative strategies to overcome technical and political barriers faced in a transboundary negotiation. The case study is the addition of the Grand Ethiopian Renaissance Dam (GERD) and considers how its operation may be coordinated with adaptations to the operations of Egypt's High Aswan Dam. The results demonstrate that a lack of coordination is likely to be harmful to downstream riparians and suggest that adaptations to infrastructure in Sudan and Egypt can reduce risks to water supplies and energy generation. Although risks can be substantially reduced by agreed releases from the GERD and basic adaptations to the High Aswan Dam, these measures are still insufficient to assure that no additional risk is assumed by Egypt. The method then demonstrates how improvements to water security for both downstream riparians can be achieved through dynamic adaptation of the operation of the GERD during drought conditions. Finally, the paper demonstrates how the robustness of potential management arrangements can be evaluated considering potential effects of climate change, including increased interannual variability and highly uncertain changes such as increases in the future persistence of droughts. Plain Language Summary With the development of the Grand Ethiopian Renaissance Dam, both a risk and an opportunity have emerged for the countries of the eastern Nile Basin. Benefits and costs of the dam are contingent not only on how the new dam will be managed but also on how the downstream countries will adapt to the new dam. This study presents a process for the countries to consider when seeking cooperative management solutions. The process begins by identifying the needs of each country and then uses both automated search methods and refinement of cooperative arrangements to iteratively seek solutions. The method focuses on how the existing management of the system can be incrementally adapted to meet the needs of all countries.