Understanding Risks and Managing Perceptions in the Nile Basin after the Completion of the Grand Ethiopian Renaissance Dam

The completion of the Grand Ethiopian Renaissance Dam (GERD) will usher in a new era of complexity in both water management and politics in the Nile Basin. The outcomes that will  aterialize for Ethiopia, Sudan and Egypt will depend on climatic conditions that are inherently unpredictable and on water management actions taken in each country. We use selected historical flow sequences that represent average, high and low flow conditions, and a calibrated Nile simulation model of reservoir operation to construct illustrative scenarios for GERD filling and operation. We focus on how a prolonged drought would create risks to water supply during and after the filling of the GERD. Because a multi-year drought will inevitably occur at some point in the future, we argue, based on our modeling results, that it will need to be carefully managed, and that its possibility should be explicitly addressed in the ongoing negotiations over Nile waters. In the absence of clear and specific agreements, there is increased potential for a breakdown in trust, social amplification of perceived risk via social and traditional media, and adoption of adversarial positions that may lead to continued diplomatic conflicts. We demonstrate how cooperative reservoir management arrangements involving information sharing and pre-agreed water releases at critical times during a prolonged drought can help to mitigate these serious water risks, and therefore contribute to management of risk perceptions.