Filling the Grand Ethiopian Renaissance Dam: seeking middle ground on the Nile

The construction of Ethiopia’s first large hydropower dam on the Blue Nile is a source of national pride for many Ethiopians and a source of concern for many Egyptians. This caution largely stems from a lack of understanding of the extent of the risks, and how these can be mitigated. New research, led by a partnership between the University of Oxford and the University of Khartoum, explores practical reservoir filling strategies, to minimize potential negative downstream impacts via transboundary coordination.

The drive for Ethiopia to harness its hydrological potential to lift people out of poverty, increasing water demands due to population growth throughout the basin, and the risk of prolonged drought will intersect on the Nile next year. The Grand Ethiopian Renaissance Dam (GERD), located upstream of the major water users in Sudan and Egypt, is now around 50% complete, and its storage reservoir will begin to fill in earnest from 2017. While the many benefits and costs of the development of the Blue Nile have been debated and analysed by scholars and practitioners for decades, there is still no agreement as to how this reservoir should be filled or ultimately managed with the other dams in the Nile Basin. New research, led by Oxford DPhil candidate Kevin Wheeler, offers analysis of some useful strategies for transboundary cooperation, helping decision makers on all sides negotiate this critical filling period.


Construction of the GERD. Photo by Kevin Wheeler.

The challenge

It has long been recognized that struggles over water resources tends to bring about more compromise than conflict between competing stakeholders, yet the process of reaching compromise and implementing an agreement takes time and effort to achieve. In 2012, Ethiopia, Sudan and Egypt embarked on a tripartite effort to resolve the issue of the GERD by jointly analysing the planning and design documents provided by Ethiopia, and commissioning social and environmental impact assessments to be conducted by two consulting firms. The results of these studies are intended to provide recommendations as to how the GERD should be filled and managed. However, contractual issues have delayed the initiation of the consultancy work, while dam construction continues unabated. It is not clear if these analyses and recommendations can be completed in time to inform the reservoir filling process, and whether a strategy to do so will be agreed upon.

Meanwhile, a joint-collaboration between the University of Oxford and the University of Khartoum, and supported by researchers from the Eastern Nile Regional Technical Office (ENTRO) of the Nile Basin Initiative (NBI), the Hydraulic Research Centre in Wad Medani Sudan, the University of Colorado, and the University of California Los Angeles, has been exploring these issues. This research does not attempt to analyse the complex social and environmental implications of the dam, but seeks to provide an objective and unbiased analysis of what the benefits are in terms of new hydropower production for Ethiopia and what the immediate risks and benefits are to downstream countries with respect to the provision of water supplies and hydropower production. Foremost, it analyses potential practical strategies for dam filling with increased coordination between the three countries to minimize downstream risks.


Nile River Basin dams.

Shared learning and new strategies.

Fieldwork in Ethiopia, Sudan and Egypt provided insight into reservoir operations in the Eastern Nile Basin, and informed the creation of a flexible hydro-policy model using the RiverWare software. This analytical tool can simulate complex dam management decisions, incorporating relevant physical processes, in a transparent manner which allows stakeholders to better understand the interaction of processes at work, provide new ideas, and test innovative strategies as they emerge.

Scenarios were developed to test transboundary policy arrangements that range from no international cooperation during filling, to various agreed annual release volumes from the GERD throughout the filling period, and finally the inclusion of additional basin-wide provisions to protect the elevation of Lake Nasser behind Egypt’s High Aswan Dam under critical conditions. Adaptation of the operation of Sudanese and Egyptian reservoirs to the presence of GERD were also simulated to demonstrate their need for well-planned management policies.

The results indicate that Sudan can largely manage their risk to major water supply diversions by changing the way they operate their reservoirs. Sudanese hydropower generation potential is likely to increase due to regulation of flows coming upstream from the GERD. For Egypt, the results show that the risk of the High Aswan Dam reaching the critical minimum power production elevation (147 m) is present, but largely depends on the volume of water in Lake Nasser when the filling of the GERD begins. An agreed annual release from the GERD significantly reduces this risk, but is not sufficient to entirely eliminate the risk of reaching this critical elevation. To avoid any unplanned shortages, an agreed annual release from the GERD can be complemented by both Egypt proactively reducing annual downstream releases and a cooperative basin-wide safeguard strategy to provide additional releases from the GERD in critical circumstances.

A peer-reviewed article documenting this research is available here. For further information contact Kevin Wheeler at