Intensive and long negotiations over the new developments on the water and energy balances of the highly populous Eastern Nile River Basin have taken place; however, yet no collaborative framework has been put in place. The disagreement concerns how to fill and operate the Grand Ethiopian Renaissance Dam (GERD) during prolonged droughts to avoid downstream water and hydropower shortages, particularly in Egypt, which fully relies on the Nile as its main water source. These concerns are intensifying as additional hydropower dams are announced to be developed upstream of GERD.

Following a settled filling phase, enabled by the above-average river flow and completed in the summer of 2024, the remaining main disagreement was determining the downstream effects of the GERD on Egypt’s Aswan High Dam during the operation phase. During average and above-average Nile flow periods with abundant water, there are no significant impacts from operating GERD. While during periods of drought and prolonged drought, the impacts are disputed and are the source of the current disagreement impeding the negotiations.

During prolonged droughts, Ethiopia wants to fix the water level of the GERD reservoir at the optimal level of 625 m and thus keep its ability to generate maximum hydropower rates, which in turn will cause a reduction in the downstream release to Egypt and hence, a significant increase in its water budget deficit. Therefore, Egypt suggested that specific quantities of water be passed during prolonged drought periods to fill the water deficit at the Aswan High Dam to avoid detrimental economic impacts.

Accordingly, releasing the suggested water volumes to Egypt during drought will affect the ability of the GERD in Ethiopia to generate maximum electricity rates. Thus, the current disagreement between Egypt and Ethiopia is centered around the definition of prolonged drought and how the GERD will be operated to achieve large and sustainable hydropower generation while reducing downstream water deficit.

This is the root of the current disagreement that is withholding the negotiations from moving forward. This disagreement is based on the different needs of the two parties, upstream and downstream, and the lack of reproducible tradeoff studies to support the different negotiation scenarios.

To address the above deficiency and to bridge the gap in the negotiations, our published study proposes the following solutions:

1. Define the prolonged drought in terms of the critical water level of the Aswan High Dam reservoir (165 m). This definition avoids the current disagreement in the negotiations on which flow rates better identify the prolonged condition in the Blue Nile and leverages any potential shortage downstream with the flow coming from the White Nile.

2. Provide detailed and numerical modeling of the economic gains and losses for Egypt and Ethiopia based on the feasibility of the negotiated operating proposals using our suggested definition of the extended drought period.

3. Provide a detailed study on the economic worthiness of intermediate operating proposals and policies quantifying the trade-off between achieving Ethiopia's needs for electricity and Egypt's needs to reduce the water deficit resulting from operating the GERD during the prolonged drought period.

4. Propose an operation scenario during a prolonged drought under which GERD can generate a sustainable amount of hydropower without causing a major downstream water deficit in Egypt.

Our main findings are as follows:

1. The definition proposed by our study for prolonged drought based on the critical level of the Aswan High Dam at 165 meters provides a suitable solution for both countries as it takes into consideration the amount of water coming from the White and Blue Niles, not just the Blue Nile, and reduces the uncertain calculations of future climate change, whether for the White or Blue Niles or both.

2. Under all the suggested operating policies, Ethiopia can generate the full possible energy during the wet and average flow periods without causing any noticeable water deficit for Egypt.

3. As for the drought periods, our study shows that the unilateral operating policy of the GERD to produce the highest rate of electricity will lead to an increase in Egypt's water deficit to high rates and major economic losses compared to the minor benefits of increasing the rates of electricity generation from the dam during that period.

4. Therefore, our study proposes an ideal cooperative bilateral operating policy for the GERD during prolonged droughts that contributes to the continuation of viable water flow to the downstream countries and maintains the GERD's generation capacity of large and sustainable amounts of energy of more than 87% of its maximum hydropower generation during periods of prolonged drought without causing tangible harm to Egypt. After the drought period ends, Ethiopia can operate the dam at maximum capacity again.

5. Our research also presents a comprehensive study of several proposed bilateral policies to bridge the gaps in the negotiations, which shows an increase in electricity generation for the dam while reducing the water deficit for the downstream country, which may help negotiators measure the trade-off of losses and benefits for each operating policy and reach a tangible solution that satisfies all parties.

Recommendations:

1. The policies proposed in our study contribute to ensuring energy stability in the region while maintaining the water balance for the downstream countries during periods of drought, resolving the major point of disagreement in the negotiations, and reaching a collaborative framework that achieves gains for all parties and ends the ongoing dispute.

2. Increase coordinated efforts between Egypt, Ethiopia, and Sudan to reduce water conflicts by exchanging data, simulation models, and hydroclimatic forecasts, which will contribute to achieving gains for all parties.

3. Increase cooperation between the three countries to study the impact of climate change on water resources and prepare to face extended drought periods. The main reliance should be on open data studies that consider the interests of both upstream and downstream countries and avoid modeling that is irreproducible or has limited data access.

The full paper: https://doi.org/10.1038/s43247-024-01821-w

Further reading: 

• https://doi.org/10.1007/s41748-023-00355-z

• https://doi.org/10.1016/j.ejrh.2023.101537

• https://iopscience.iop.org/article/10.1088/1748-9326/ac0ac9

• https://doi.org/10.1016/j.jhydrol.2024.131999

• https://www.sciencedirect.com/science/article/pii/S1470160X22011335

Poster image source from Vecteezy (dear.augustrain483834, free license)