ALTHOUGH DESCRIBED AS BEING the backbone of Africa’s electricity supply, there is still huge untapped hydropower potential across the continent. In fact, as the International Hydropower Association acknowledges, at 90%, Africa has the largest proportion of unexploited capacity in the world.
With the 2GW of hydropower capacity installed increasing the region’s total to 42GW in 2023, the IHA says Africa still lags far behind what’s needed to meet energy goals. Numerous regulatory and market issues are slowing down any development and creating a backlog of projects, leading to delays and even cancellation.
One of the major ongoing water conflicts in Africa focuses on the Eastern Nile River Basin where a decade of negotiation and mediation has been unsuccessful.
The longest continental river on Earth, the Nile travels through 11 countries and runs through diverse climatic, topographic, environmental, and socio economical landscapes. As Heggy et al explain in their research published in Communications Earth and Environment, this unique hydrological and environmental system is an essential freshwater resource, especially for downstream riparian countries such as Egypt and parts of Sudan.
Precipitation patterns have been changing over the Nile River Basin since the 1900s, leading to consistent decreases in the average annual natural river flow, even before the era of mega dam building began. However, the construction and operation of such dams since the 1960s have caused disputes and brought global attention to water allocation and management issues in the basin.
Since Ethiopian authorities started building the 16,000GWh Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in 2011, the Blue Nile River Basin countries of Egypt, Sudan, and Ethiopia, have been negotiating on its filling and operation due to the hydraulic uncertainties associated with prolonged droughts.
Heggy et al claim their research provides comprehensive assessments of the efficiency of multiple drought-mitigation policies for the impact of dam operation. Their results suggest almost optimal hydropower can be generated without a noticeable downstream deficit during wet, average, and temporary drought flow conditions. For prolonged drought, an ideal operation policy has been identified which allows GERD to generate a sustainable 87% of its optimal hydropower without creating additional downstream water deficit.
Furthermore, the authors provide four intermediate policies demonstrating enhanced upstream hydropower generation while minimising dam induced downstream water deficits. “Our findings attempt to bridge the negotiation disparities in the Nile hydropower mega-dam operations during prolonged drought and foster an actionable and collaborative framework,” they say.
The hydro-political context surrounding the GERD project is described as being complex and multifaceted, involving a range of historical, geopolitical, economic, and environmental factors and negotiations. The authors say their study provides a path forward to resolve the scientific disparities between the Nile River Basin countries and strive towards a win-win collaborative framework. However, they do caution that the GERD operation may have benefits or adverse effects on Sudanese dams, which were not part of this study need to be simulated and studied separately.
Small Sudanese dams
Small dams in Sudan are often constructed as earthen embankments with controlled or uncontrolled spillways, storing seasonal runoff from Wadis, with capacities ranging from 1-10Mm3. Despite their importance, in his research published in the International Journal of Water Resources and Environmental Engineering, Hamid Omer Ali says many small dams face technical and management challenges that undermine their sustainability.
With more than 100 of these dams across the country, as of 2023, approximately 30% of them are reported as being non-functional. Technical challenges, insufficient maintenance, inadequate management, and climate change effects have led to numerous physical failures in these small dams over the past decades. This is demonstrated in the North Darfur State where 10 out of 33 small dams have experienced partial or complete failures. The main reasons behind these were attributed to:
- A lack of proper operation and maintenance practices.
- Insufficient coordination and communication between upstream and downstream stakeholders. Institutional instability.
- A shortage of hydrological, socioeconomic, and environmental data.
- Poor designs.
- Non-adherence to local norms and standards.
- Poor experience of some contractors.
- Lack of community ownership
The Um Dafoug dam in South Darfur, Sudan is said to exemplify these challenges. With a storage capacity of 10Mm3, it spans a transboundary seasonal stream flowing from Sudan into the Central African Republic.
Constructed in 1997 by the South Darfur State Water Corporation in collaboration with the Federal Ministry of Irrigation and Water Resources in Sudan, the dam serves as the largest and most significant water dam in the region.
Hamid Omer Ali explains that the dam’s main objective was the provision of a reliable source of water for multiple usages, including providing local pastoralists with water to ensure they could stay with their livestock within South Darfur State – instead of having to venture beyond the borders into the Central African Republic where they can be exposed to xenophobia.
Although strategically significant, the Um Dafoug dam suffered three failures, with the most severe in 2022 caused by a combination of extreme flooding and critical design flaws. Inadequate studies and assessments during planning resulted in insufficient spillway capacity and persistent water seepage, compromising the dam’s structural integrity.
Management shortcomings further exacerbated these issues. Limited community engagement, poor coordination among institutions, the absence of a community-based maintenance framework, and the lack of a tariff system for water usage highlight systemic weaknesses, the author claims. While unregulated water use has led to environmental degradation, soil erosion, and increased risk of waterborne diseases.
According to Hamid Omer Ali, from its initial planning through to construction and ongoing management, the dam was marked by remarkable shortcomings and deficiencies in planning, design, construction, and subsequent management. These contributed significantly to its frequent failure.
Furthermore, this “rendered it a prime example of shortsighted rural development and a classic example of the tragedy of the commons in which unregulated and open access to natural and water resources is destroyed or depleted because each user acts in their own interest”.
The example of the Um Dafoug dam is said to highlight critical lessons that state water corporations and other water authorities in Sudan, as well as in similar arid and semi-arid regions, must urgently address. These are critical for ensuring the safety and sustainability of small dams and for avoiding the pitfalls of unregulated open access to water sources, particularly in rural areas across the country. With this in mind, the author recommends a holistic approach rooted in the principles of integrated water resources management, emphasising collaborative engagement among diverse stakeholders, plus the establishment of a co-management system, governance, and transparent tariff collection mechanisms.
This article first appeared in International Water Power magazine.
References
Grand Ethiopian Renaissance Dam can generate sustainable hydropower while minimizing downstream water deficit during prolonged droughts by Essam Heggy, Abotalib Z. Abotalib, Jongeun You, EmmanuelHanert, Mohamed Ramah. Communications Earth & Environment| (2024) 5:757 https://www.nature.com/articles/s43247-024-01821-w
Advancing integrated water resources management approaches for the sustainability of small dams in arid and semi-arid regions: A case study of the Um Dafoug dam in South Darfur State by Sudan Hamid Omer Ali. International Journal of Water Resources and Environmental Engineering. Vol. 17(1), pp. 1-16, January-March, 2025 DOI: 10.5897/IJWREE2024.1082 Article Number: C15135772913
