Monday 08 / September / 2025
Addis Ababa: The Grand Ethiopian Renaissance Dam (GERD), 14 years in the making, will be officially inaugurated this week.
At 1,800 metres (nearly 6,000 feet) wide, 175 meters high and capable of holding back up to 74 billion cubic metres of water in a reservoir covering an area larger than the city of London, the massive structure is the largest dam in Africa.
The new dam on the Blue Nile, a main tributary of the Nile, has already been generating renewable hydroelectric power since early 2022, and the project eventually expects to double Ethiopia's current electricity capacity. As much as half of the country's population doesn't have reliable access to electricity, leaving many to rely on burning polluting fuels such as wood, coal and gas.
But for downstream states Egypt and Sudan, the waters of the Blue Nile are vital — and increasingly scarce. A 2019 study published in the journal Earth's Future found that annual demand for water in the Nile Basin could regularly exceed supply by 2030.
Egypt and Sudan have opposed what they describe as Ethiopia's "unilateral measures" to control the river's flow, fearing the effects on water availability, and have called for joint management of the river. But Ethiopian Prime Minister Abiy Ahmed recently sought to downplay those concerns, stressing that GERD "is not a threat."
Abiy has said the new dam will help control the catastrophic floods that regularly hit eastern Sudan, and generate electricity for export in the Horn of Africa — thereby boosting the African Union's regional development plans. Ethiopia has already signed electricity contracts with Kenya, Sudan and Djibouti, and discussions are underway with other neighbouring countries.
"Ethiopia remains committed to ensuring that our growth does not come at the expense of our Egyptian and Sudanese brothers and sisters," Abiy said in a speech to parliament in July. "We believe in shared progress, shared energy and shared water."
Hydropower vs. irrigation
Only a short 15-kilometre (9-mile) drive away from the GERD, Sudan will be the first to feel the effects of the dam — good or bad. Millions of people in the country, already beset by an ongoing civil war, a humanitarian crisis and increasing drought and desertification, depend on the river for drinking water and farming.
"Sudan faces very real risks because they're immediately downstream of the dam," said Kevin Wheeler, a research associate at the University of Oxford's Environmental Change Institute.
He told DW that while the GERD will help regulate floods, Sudan will want to ensure that the Ethiopian side doesn't release too much — or too little — water at any one time.
"Day-to-day coordination is the main issue. And of course, dam safety is a primary issue," he said.
After flowing through Sudan, the Blue Nile joins the Nile and wends it way north toward Egypt, which relies on the river for around 90% of its water. A growing population and dwindling supplies has Cairo desperate for every drop, but Wheeler said the fact the GERD will be used to generate electricity is actually in "Egypt's best interest."
It means the water will continue to flow downriver after it goes through the generating turbines, rather than stay in Ethiopia to be used as irrigation.
Wheeler, who has worked with research institutions across Ethiopia, Sudan and Egypt on the development of the Nile Basin since 2012, said Cairo's main issue with the GERD is Ethiopia's decision to build it without first reaching agreements with neighboring states.
"Egypt is understandably concerned of setting a precedent for future [water] developments," he said.
Since Ethiopia began construction of its first major dam project in 2011, Egypt and Sudan have pushed for a legally binding deal to guarantee water flow, operational coordination and safety measures and a legal mechanism for resolving disputes.
But several attempts to reach an agreement over the years have failed.
"This dispute [over water] has an almost century-long history and is therefore deeply emotionalized, not only among the political leadership of the respective countries but also within their populations," said Tobias Zumbrägel, a postdoctoral researcher at Germany's University of Heidelberg. "This naturally makes compromise more difficult."
The GERD — which Zumbrägel highlighted was as a "prestige project carrying strong symbolism of nation-building and pride" — is just the first in a series of possible hydroelectric dams Ethiopia has planned for the Blue Nile in the country's northwest.
Ethiopia is also looking at using some of the river water above the GERD for irrigation.
"The biggest obstacle [to a deal] is whether upstream countries will start consuming more water," said Wheeler. "Egypt would, of course, like to keep Ethiopia from using additional water. And Ethiopia won't agree to anything that suggests [it will restrict its future water use]."
GERD exploits Ethiopia's 'exceptional hydropower potential'
While Ethiopia does have potential when it comes to other forms of renewable energy like wind and solar, for Zumbrägel, whose work focuses on environmental degradation and climate policy, it makes sense for the country to exploit its "exceptional hydropower potential" with the GERD project.
"Hydropower can provide valuable grid stability services and enable regional electricity exports in ways that solar and wind alone cannot easily achieve without large-scale storage solutions," he told DW by email.
"It's really a different scale of energy production," said Wheeler. "And it's all generated from one location. If it's diffused [in the case of wind and solar], then you have much more complex maintenance issues."
The effects of climate change — unpredictable rainfall, prolonged droughts and rising temperatures — could make hydropower generation more unpredictable in the coming decades. But Wheeler said this might not be the case for Ethiopia, with most projections for the Nile Basin showing an increase in average rainfall, potentially interspersed with longer periods of drought.
Climate researchers have pointed out that the GERD and Egypt's Aswan High Dam, built in the 20th century to control irrigation and generate electricity, could even help mitigate some climate challenges, if jointly operated. Evaporation rates in the Ethiopian highlands are much lower than in Egypt's arid, desert climate, and if both reservoirs worked together they could ensure sufficient water for their respective needs.
"The role of dams may actually become quite important, just like the Aswan Dam manages droughts in Egypt. Any dams within the system will also help manage the risk of multiple years of drought for the downstream countries," said Wheeler, explaining that water stored upstream in Ethiopia could potentially be released to help Egypt and Sudan in times of water stress.
One concern, he added, could be how quickly Ethiopia decides to refill a drought-depleted GERD reservoir to restart electricity generation, with a rapid replenishment possibly prolonging drought conditions downstream.
