In September, Ethiopia completed the fourth and final filling of the Grand Ethiopian Renaissance Dam, now the largest hydroelectric power plant in Africa. How is this mega project expected to impact its neighbor Sudan?

By Arthur Larie and Bastien Massa


As Ethiopia completed the fourth and last filling of the GERD this summer, Sudan is still wondering which benefits will come from this mega project

“The Nile River remains the most important source for water security in Sudan that provides water for municipal, agriculture and industrial sectors as well as for groundwater recharge. The high dependency on the Nile, as a transboundary river, put Sudan’s WEF [water-energy-food] security on a high risk of external changes upstream like the construction of the GERD. 

“Water security is particularly important in Sudan as food and energy securities are extremely reliant on water availability. The country has a short rainy season that extends for about three months, and recently, this rainy season has become less reliable due to climate change effects. This made rainfed agriculture less attractive and profitable compared to irrigation agriculture. For energy security, more than half of the country’s electricity comes from hydropower dams located along the Nile and its tributaries.” Mugahid Elnour (The impact of the Grand Ethiopian Renaissances Dam on the Water-Energy-Food security nexus in Sudan)

The starting point of this investigation was for us the absence of clear information about what would be the impact of the Grand Ethiopian Renaissance Dam (GERD) on Sudan.

The position of Ethiopia was evident and well-known: The GERD, the largest hydropower dam in Africa, was a way for the country to produce a lot of electricity, enough to supply an important internal demand and provide electricity to its neighbors. On the other side, Egypt’s position has been shared in the media many times: 97 percent of the country relies on the Nile river water, and the GERD, especially the filling stages, was expected to reduce the amount of water available. And many commentators have spent a lot of time studying and judging the legitimacy of both countries’ positions.

Partly due to its geographic location, in between, Sudan was said to be negatively impacted by the GERD, as any downstream country could be impacted by such massive infrastructure on the river. If many initially teamed Sudan with Egypt, the first studies started to show how the in-between country could actually benefit from the GERD.

It was the promise of flood mitigation, electricity production and a constant water flow all over the year. The GERD, which had been rejected, was suddenly praised. Yet, few people have questioned the veracity of allegations about the GERD’s positive or negative impacts. Some researchers published detailed articles trying to go further into the quest for answers.

Over two years, we met with researchers, economists, environmentalists, officials and local populations trying to draw a clear picture of what is at stake, and how Sudan will really benefit or suffer from the dam.

In September, the Ethiopian government announced the fourth and last filling of the GERD, 12 years after the first stones were laid for Africa’s largest hydroelectric dam. This historic moment happened as a new round of negotiations are running to solve the main disputes over Nile water sharing between Sudan, Egypt and Ethiopia. 

Most of this investigation was produced before Sudan entered war on the 15th of April 2023, a struggle for power between two generals and two armies. On the one side is the national army, led by general Abdel Fatah Al Burhan and the Rapid Support Forces. One the other side is a paramilitary militia led by general Hemeti. 

The outbreak of the war followed two years of instability. On 25 October 2021, after two years of transitional period that should have led to election, the Sudanese military, led by General Abdel Fattah al-Burhan, took control of the government in a coup. For days after the coup, civilians started a campaign of civil resistance against the military junta. The country also entered a deep economic crisis.

After a year of protest, military and civilians finally signed a new political agreement in December 2022 for a future civilian government. But many political parties and the entire civil society did not recognize the agreement, leading to the current conflict.

In the ongoing civil war, more than 10,000 people have died as of November 2023 and millions have fled the country. This deadly conflict for power is sure to have a long-term impact on the region and control over the Nile.


A huge dam, too close?

The Roseires Dam, on the Nile in southeastern Sudan at Ad Damazin, may be the first affected by the operations of the GERD. The Roseires dam is located on the Blue Nile River, close to Sudan’s southeastern border with Ethiopia, near to where the GERD is constructed. After passing the GERD, it is the first dam that the river meets.

Originally completed in 1966 for irrigation and hydropower purposes, the dam was heightened in 2013.

Based on the operation of the GERD and agreements, the water levels of the reservoir of the Roseires dam are expected to change, potentially affecting the reservoir and the technical operation of the Roseires dam.

The communities near the reservoir now find themselves caught in between two large dams in two different countries, which both affect their lives and livelihoods.

Once arriving in Damazin, the 200,000-population capital city of the Blue Nile State, you need four wheels to follow for two hours the bumpy roads leading to Village 1 in Wad el Mahi locality. In this village, many people remember the impacts of an earlier heightening of the Roseires dam. More than 2,000 people were relocated when this dam was renovated a decade ago.

“We were living in our village on the shores of the Roseires dam lake until 2012 when they decided to heighten the dam; our former village is now underwater, so we have been displaced here,” said Sheikh Salman, the fishery leader of the village. 

Sheikh Salman takes us on a small boat to the center of a bay on the lake. He stops rowing and points to a location on the water. 

“Under me was the market, and my house was just over there. Now, there are 6 meters deep water.”

Village 1 gathers communities living around the lake. Eleven other villages have been created around the Roseires reservoir to host the 20,000 people displaced. While some locals praise the new housing and the available amenities, many also miss their former village and the proximity with water.

In village 6, where the government promised to provide facilities for the new settlements, nothing has been done eight years later, and most basic infrastructures are still lacking.

“They only came once; then we started to build our own houses by ourselves, and NGOs came and took the role of the state. Eight years later, we still don’t have access to water. Before, we were living on the banks of the Nile, so things were easier. Now we have to walk for hours every day to get water from the river,” said Amira Osman, a local resident.

Amira Osman
Amira Osman, displaced from the heightening of Roseires Dam, Blue Nile State

When asked about “sad en-nahda,” the Grand Ethiopian Renaissance Dam in Arabic, people get confused. If they know that 116 kilometers away one of the largest hydropower dams of Africa is being built, they do not know what could be the consequences.

“The first question is, ‘what if the dam breaks? Will we be washed out in some minutes, no time to flee?’” said Um Khadija Salman, a community member. “But for the issue of fish, agriculture, etcetera, we have no idea of the consequences of the dam.”

Caught between two dams, these communities will be the first affected, positively or negatively, by the operations of the GERD.

“The risk for the people between the two reservoirs depends on the information given by Ethiopia – timing, quantity – it is very important to prepare our people,” said Mustafa Hussein, a member of the technical committee for the GERD negotiation team in Sudan.

In the Roseires reservoir, people used to grow food during the dry season when the level of the dam was low, and harvest before the rainy season when the dam was filled.

But with the GERD and the control over the Blue Nile flow, the Roseires reservoir will not fluctuate as it used to be and the floodplains will be filled over the year with water, preventing the farmers from practicing recession agriculture.

In the reservoir of Roseires dam, many people also support their livelihoods by collecting the driftwood that floats from the mountains of Ethiopia down the Nile. But with the new Ethiopian dam, most of the wood becomes stuck in the GERD reservoir and no longer flows downstream, Al Jazeera reported.

©Arthur Larie 2
©Arthur Larie 5

South Damazin, Blue Nile State, 2020: In the reservoir of the Roseires dam, wood collectors are the most directly impacted by the GERD. The logs washed down by the rains in Ethiopia used to provide an income for these “wood fishermen.” Now, many of them have already given up and have taken on small jobs in the surrounding towns.

How Will the GERD Affect Sudanese Dams?

“We as Sudanese; we mostly rely on nature for our energy. The Nile gives us hydropower but it is an uncertain river, so we face many difficulties,” said Selma Al Ghadi, the legal advisor for the Sudanese negotiation team on the GERD.

As of 2020, around 60 percent of Sudan’s electricity came from hydropower generation produced in the various dams built along the Nile River and its tributaries. But electricity access remains a challenge for this country, where only 55 percent of the population could benefit from that energy as of 2020, mainly in cities.

For decades, the main dams in Sudan that produce electricity have lost capacity due to the accumulation of sediment in the dams’ water storage. 

With the GERD, the country expects to see its hydropower capacities increase. The GERD is expected to regulate the flow of the Blue Nile, deliver a higher level of water during the dry season and reduce the siltation of Sudanese dams by keeping most sediment behind the GERD. These impacts are expected to increase hydropower generation and provide more water for irrigation in Sudan. 

However, these positive impacts depend on open and coordinated information regarding how Ethiopia will manage the dam. The current deadlock in the negotiations raise concern about the positive effect of the GERD on Sudan.

Located at Sudan’s border with Ethiopia within the Blue Nile river, the Roseires dam is strategic for the Sudanese economy and water supply. Decided under the 1959 agreements, which divided the share of the Nile water between Sudan and Egypt, Roseires was meant to control the floods coming from the Blue Nile and increase water availability for irrigation schemes, in particular the Gezira and Managil schemes, which water the biggest agricultural projects of Sudan. 

The Blue Nile flows from Ethiopia and joins the White Nile, originating from Lake Victoria, in Khartoum to form the main Nile River. This section of the river, though shorter, provides the majority of the main Nile’s water during the rainy season. 

Location of dams in Sudan 07

“The most important and critical structure in Sudan is the Roseires dam,” highlighted Mustafa Hussein, the head of the technical group of the Sudanese negotiation board for the GERD. 

As the first Sudanese dam on the Blue Nile, Roseires plays a key role in the Sudanese dam system. Even the Jebel Aulia dam operation, located south of Khartoum on the White Nile, depends on Roseires. Any change in the operation of Roseires affects the dams downstream.

In 2015, about 65 percent of the country’s electricity came from hydropower. The Sennar dam, built on the Blue Nile 260 kilometers downstream of Roseires, has a hydropower capacity of 15 megawatts and is a vital infrastructure that secures drinking water supply during the dry season. It also contributes to the Gezira and Managil irrigation projects, the main food security providers of Sudan. Its initial storage capacity was 930 million cubic meters, but the total capacity of the reservoir at its maximum level has reduced to 390 million cubic meters due to sedimentation.

Up north, on the road to Egypt, Merowe Dam is Sudan’s largest hydroelectric dam with a hydropower capacity of 1,250 megawatts and a storage of 12,500 million cubic meters: about 15 percent of the Nile’s annual flow of 84,000 million cubic meters registered at Aswan, Egypt. 

In 2010, the Merowe dam was generating more than 60 percent of Sudan’s electricity consumption. These two dams, Sennar and Merowe, are vital for Sudan and rely on the operations of the Roseires dam, which is now dependent on the operation of the GERD.

Indeed, Roseires has a limited capacity of 7,000 million cubic meters in its reservoir. To produce electricity, the turbines need a certain amount of water. Any release or capture of water from the GERD will influence the operation of Roseires dam. 

If the amount of water flowing from Ethiopia is too high or too low, it can affect the hydropower plant of Roseires and the rest of the dams downstream.

“You need to behave differently across the year. It is not only about cubic meter, but it is also about when do you send the water. The difference in seasonality between the dry and the rainy season is important,” explained Muhammad Hassan, an independent Sudanese researcher.

Therefore, Sudan and Ethiopia must agree on an optimal amount of water released daily that will adapt to seasonality and not harm infrastructure downstream, while ensuring sustainable electricity production in the GERD. This situation is key to understand the tensions that affect Sudan and Ethiopia relations regarding the GERD negotiation.

What is at stake in the negotiations?

After 10 years of negotiations, and despite the signature of the Declaration of Principles in 2015 – in which the countries committed to “cooperation, equitable and reasonable” use of water resources – the three states are still struggling to find an agreement that could benefit all parties. 

Since Ethiopia started operating the GERD’s first turbine in February 2022, Sudan and Egypt are still asking Ethiopia to sign a binding legal agreement on 4 major aspects:

  • Drought mitigation
  • Timeline for the filling and operation of the GERD
  • Role of Mediators
  • Scientific and technical assessment, especially regarding the environmental consequences on the downstream.

Sudan also blamed Ethiopia for a lack of communication regarding this important event. 

“We didn’t know they would launch the first turbine before they announced it,” said Mustafa Hussein, the head of the technical group of the Sudanese negotiation board for the GERD.

Indeed, Ethiopia is not ready to sign, fearing that any agreement would possibly limit its sovereignty over the dam.

“Ethiopia wants to make sure the agreement is sufficiently flexible, that the quantitative elements of the GERD agreement are adjustable; they don’t want to be locked into a GERD agreement,” explains William Davison, senior analyst for Ethiopia at Crisis Group, a think tank that performs research and analysis on global crises. 

Since, the negotiations are currently quiet and the main negotiating points by Sudan and Egypt are not yet fulfilled.

Is a Water Release Agreement Needed?

A current issue is the effect the GERD could have on Sudanese dams, especially in a changing climate.

Egypt argues that the GERD operation should be contained with climatic scenarios so as to avoid affecting the part of the water allocated to Egypt (55 billion cubic meters (BCM)) and Sudan (18.5 BCM) by the 1959 agreement. But Ethiopia contends that this is an attempt by Egypt to secure its claims over Nile water.

Sudanese dams are not made with large water storage capacities like the Aswan High Dam (160 BCM) in Egypt to face any potential water shortage that could occur with the GERD (74 BCM) in a time of climate change.

Second, since Sudan’s Roseires dam is located very close to the GERD, “any water released from the GERD unknown by Roseires engineers can be a source of danger,” according to Mohammed Basheer, a water resources researcher at Humboldt University of Berlin.

Two dimensions have to be considered in that case. First, if the Roseires dam is already filled at a high level and unanticipated water comes from the GERD, the dam can overtop, with water passing over the dam. Roseires dam has a small capacity and its turbine can produce electricity only with a certain amount of water.

Another issue is the day-to-day water variation released by the GERD. If the water received by the Roseires reservoir day-to-day changes too much, the dam might face safety risks, and in the worst-case scenario, collapse.

“Important changes in daily level variation of the incoming flow will affect the stability of the Roseires dam. This will affect the clay cores, because the variation can make the clay cores very weak and it can collapse,” because the dam embankment is mostly made of earth, said Sudanese Technical GERD Advisor Mustafa Hussein.

Therefore, for Hussein, agreeing on limitations is crucial to ensure the safety of Roseires and the operation of the dams downstream.

The researcher Basheer agreed. “I don’t see any scenario without a binding agreement. This will provide assurance on the water released and data exchange. If no agreement is reached, the Roseires dam cannot be operated safely. The issue of data-sharing needs to be handled as soon as possible,” warned Basheer.

The situation is complex. On one hand, Sudan stands in favor of the dam, regarding the positive aspects it should bring to the country. But the current lack of cooperation with Ethiopia makes the experts less confident about the project.


“If the project is managed cooperatively between Sudan and Ethiopia, the dam is going to positively affect Sudan in terms of irrigation potential, silt, enhancing Sudanese electricity production for their dams, but only in a case of cooperation. However, the lack of a formal agreement increases Sudanese concern about the project,” the Crisis Group analyst Davison concluded.

The challenges of non-cooperation struck Sudan in 2021, when Ethiopia started filling the GERD without warning Sudan. “A monitoring station located at the border between Ethiopia and Sudan showed the Nile’s water level plummeted 100 million cubic meters between July 12 and 13, Sudanese government logs show. The last time they dropped that low was in 1984, the driest year on record,” Bloomberg reported.

Further downstream, six drinking water stations for the capital, Khartoum, ran dry, leaving most of the city’s five million people without piped supplies for three days. Irrigation systems along the Nile’s banks stopped working, damaging crops.

Expected Benefits from the GERD for Sudan

According to most predictions, the GERD is expected to have a positive impact on the Sudanese dams and economy. A research led by M. Mordos in 2018 stressed that the GERD could increase electricity production by 2,000 GWh (gigawatt hours), which is a quarter of the whole country’s average electricity generation before the GERD. This increase is much needed, as the Sudanese people face electricity cuts on a daily basis.

In the long term, Sudan could benefit from the expected regulated flow from the Nile. During the flood season, between July and September, water is stored in the reservoirs for the dry season. Until now, the dams were operating mainly during this three-month rainy season, and then their efficiency drastically decreased during the nine-month dry season.

With the GERD, the flow of the Blue Nile is expected to become regular throughout the year. In the long run, this means that the turbines will be able to work year-round generating energy, increasing the efficiency of Sudanese dams.

According to the 2018 research by M. Mordos, “GERD is going to negatively affect hydropower generation in Sudan during the first reservoir filling, while positively increasing the opportunities to maximize hydro-generation by a considerable amount if new operation policies are adopted.” 

The main beneficiary is expected to be Merowe Dam, Sudan’s biggest hydropower plant (1,250 megawatts). 

Graphical stabilisation

Growth of electricity production is also expected from reducing siltation in Sudanese reservoirs. Currently, the Roseires and Sennar dams have lost at least 36 and 71 percent of their capacity because of siltation: the accumulation of sand, mud and soil in their reservoirs. 

The GERD is raised as a solution to this problem. Expectations are that 86 percent of Blue Nile sediments will be stuck in the dead storage of the GERD.  This will reduce the sediments that come to Sudan and increase water storage capacity in the Roseires, Sennar and Merowe dams, as well as electricity production. 

Still, there is one major requirement for this to happen: an effective collaboration between Ethiopia and Sudan: between the GERD operation and Sudanese dams. 

But many unknown factors remain, in particular the quantity of water the GERD will send downstream.

“Since there is no binding agreement between the three countries, there is no guarantee for Sudan to know how Ethiopia will operate the dam throughout the year. For Ethiopia, the operation should be dynamic and adapt regarding water availability, water demand and electricity needs; thus they don’t want to sign anything that could prevent them from operating the dam accordingly.”


Another issue is the electricity production needed in Ethiopia. The release of water from the GERD depends on the quantity of electricity the country needs to generate for both domestic uses and export.

The 6 GW Grand Renaissance hydroelectric power station is expected to generate approximately 15,000 GWh of electricity a year, which is the equivalent of the current 14,900 GWh electricity production of Ethiopia. 

More water, more irrigation?

The contested 1959 Nile Water Agreement between Egypt and Sudan allocated the new republic 18.5 BCM as the Sudanese share of the Nile water. But since then, a lack of infrastructure and instability due to internal conflicts has prevented the country from utilizing this share. 

As of 2019, Sudan was using only 13.8 BCM. With the GERD, the republic expects to fill this gap and use much more water for new irrigation projects.

In Sudan, the agricultural sector represents about 80 percent of the country’s export and 60-80 percent of household income. One of the expected impacts of the GERD is the steady flow of water, which is expected to help the country develop its irrigation potential. 

The Gezira irrigation scheme, launched in 1925 after the Sennar Dam was built, covers 880,000 hectares: half of the country’s irrigated lands. A slight slope from the Blue Nile shores allows a Gravity Irrigation System that takes 35 percent of Sudan’s water share dealt in the 1959 agreement. Nearly 120,000 farmers are working or relying on this project, in addition to all the industries depending on the raw material.

One of the expected benefits of the GERD for Sudan is the possibility to create nine new irrigation schemes located around Gezira, Managil, Rahad and Dinder.

Once again, this will depend on the way Ethiopia decides to produce electricity with the GERD. At least two options could be implemented: constant electricity production throughout the year, or maximal electricity production during the rainy season to fill other reservoirs in the country and reduced electricity production during the rest of the year. Right now, nothing has been decided yet.

Tuti Island 4
Northern State, Sudan 2020: If operated in an efficient and coordinated manner, the dam should allow for better irrigation over larger areas and make year-round agriculture possible.

“The GERD is made to be at its highest potential during the rainy season, but Sudan would have benefited more from the dam if they operated it throughout the year,” said Crisis Group analyst William Davison.

In the 1970s, nine new irrigation schemes were designed for the region of Gezira, but none of them have yet been implemented. The GERD raises hopes to finally establish these schemes. With an expected increase in the Nile flow, the government plans to use the Roseires dam to irrigate these new lands, depending on available resources for infrastructure and capital. 

Sudan irrigation schemes


However, increasing irrigation may have other consequences. “Sudan can implement all the schemes, but increasing water use for agriculture is going to impact the electricity generation in Merowe dam and reduce the Nile flow in Egypt,” said researcher Mohammed Basheer.

A 2017 research led by Abbas Sharaky also estimated that a steadier flow of the Blue Nile will increase groundwater recharge in Gezira state, where about 85 percent of people rely on underground water. The study concluded that if the GERD keeps the water level high throughout the year, this will create new economic opportunities to develop agriculture year round.

Based on the researchers’ insights, it is possible that Sudan could start implementing the new irrigation schemes on the Blue Nile when the GERD’s long-term operation starts, given that the river flow would become regular. One assumption is that Sudan could implement one of the new irrigation schemes every three years, starting from the beginning of the GERD’s long-term operation. 

Economic benefits…

One of the main arguments in favor of the GERD in Sudan is the potential economic benefits the country can achieve from the dam.

A recent study points out that compared to a no-GERD situation, the total economic value for Sudan’s GDP could be between USD $47-83 billion in the 2020-2060 period, if all nine potential irrigation scheme are built (without taking into account the initial capital required). The difference would come from the degree of cooperation between both countries and if Ethiopia chooses to maximize its electricity production or support Sudanese irrigation development.

This economic growth would come partly from expanding crops in the nine potential new irrigation schemes along the Blue Nile (between US $3.58-5.46 billion). To this will also be added a net increase in the agricultural sector, expected to range between US $2.84-4.67 billion.

Industrial growth is expected at US $25.19-29.56 billion over 2020-2060. “These gains result from the additional crop output due to agricultural expansion and the value-added across the economy,” the study concludes.

Benefits to households over 2020-2060 range between US $23.41-24.89 billion, with a bigger expected improvement for rural households than urban households.

“Results on household welfare show disparities between different household groups. This occurred because irrigation expansion benefits the land and capital owners (mostly rural rich) as well as agricultural workers (mostly rural non-rich), while additional energy generation mostly benefits urban consumers,” according to the study.

Considering these figures, the main question is not whether the GERD can be profitable to Sudan, but rather how to maximize this profit. Collaboration would lead to bigger benefits for Sudan.

Sudan is also expected to increase economic benefits by decreasing sediment deposited inside the dam reservoir. By retaining up to 86 percent of the 140 million tonnes per year of sediment measured at El Deim Station near the Ethiopian Sudanese border, Sudan should reduce drastically the high cost associated with sediment deposit, including costs for dredging, clogging, and infrastructure maintenance, and reduction in hydropower efficiency.

According to a 2010 book by Seifeldin H. Abdalla, “70 percent of the operation and maintenance budgets go for dredging of sediment deposition in irrigation canals and weed clearance associated with sedimentation.”


…that hide discrepancies within the population

It is now common to hear from some Sudanese or Ethiopian high-position officials that the GERD will have a net positive impact on Sudan. If most of the population would benefit from a collaboration on dam management, and if the balance is in favor of the positive, the question remains: What about the losers of the dam?

In Sudan, some voices are rising up about the dam’s potential negative effects on the Sudanese population. 

Dr. Mohammed el Amin – the previous director of Merowe Dam – is one of these. Sudan’s highest population density is located along the Blue Nile, yet no studies measuring potential risks and hazards of the GERD in Sudan have been conducted. Since the beginning of the GERD’s construction, Dr. Amin has not stopped warning of the danger of such a dam if no clear study is undertaken to understand the effect of such infrastructure on the downstream countries.

“When you plan to build such a large dam, you first have to lead a study on the people and ecosystem downstream to understand how they will be affected by the dam. From this study you decide the size of the dam. But the Ethiopians did not respect the downstream people; they just claimed their historical right to use the Nile. We are all in the dark right now,” Dr. Amin said.

End of the Floodplains?

As the river’s “regime” – the changes in its discharge – will change, many unknowns remain.

First, flood mitigation. This phenomenon has been presented to and by Sudan as the number one benefit of the GERD. But for the millions of Sudanese living along the Blue Nile river, many have depended for centuries on the natural flooding of the river to grow their crops.

Traditionally, during the rainy season, water floods the shores of the river, depositing fertile silts. After the water recedes, farmers cultivate the lands previously occupied by water. But by allowing a higher and steady flow of the Blue Nile, the GERD will wipe out this so-called recession agriculture, the same way it was wiped out in Egypt after the building of the Aswan High Dam.

Nationwide studies regarding the loss of floodplains are still pending, but a localized research from Mohammed Basheer  in Khartoum state, which has the most floodplain agriculture, shows that of the 393 square kilometers of existing floodplains, two scenarios are possible after the GERD operation:

1 – If the GERD starts a year at a low-level storage, the flooded area in Khartoum in that year would decline more, to around 125 square kilometers.
2 – If the GERD starts a year at a high-level storage, the flooded area in Khartoum in that year would decline less, to around 352 square kilometers.

Much uncertainty remains, as Ethiopia has not released information to Sudan regarding its way of operating the GERD. However, according to data, floodplains are likely to disappear along the Blue Nile and the main Nile, requiring a change of livelihoods for farmers and brickmakers who rely on silt coming with the floods for their production.

According to Sudanese researcher Hanan Muddathir, some crops such as sunflower, sorghum and sesame will also be affected by the change in the stream and the disappearance of floodplains.

The change in agricultural behaviour must be compensated for: Farmers will need to invest in new equipment to grow their crops to compensate for the loss of their lands and silt. But when proposed to Mustafa Hussein, the technical GERD advisor, he answered that this should not be the Sudanese government to compensate, but the Ethiopian government: another political dispute.

However, the subject is not part of the negotiations, and it is unlikely that Ethiopia could accept such a proposition, as William Davison explains. 

“If Sudan asks for compensation, Ethiopia would answer that the GERD will increase the electricity capacity of all the Sudanese dams thanks to silt reduction, thus I imagine this point will not be negotiable between the two countries,” the Crisis Group analyst said.

Brick Makers

Another issue is what will happen to Sudan’s brick industry. As more than 80 percent of the Blue Nile’s silt will be retained by the Ethiopian dam, the bricks industry – which uses a mix of clay to produce the materials – will be severely impacted.

Exact figures of the economic weight of this sector are not available, but some figures show how the issue cannot just be swept away from the GERD debate. 

The red brick industry in Sudan has been soaring since the 1980s. Production increased by 2,100 percent between 1975 and 2006 and by more than 50 percent just between 2004 and 2006. According to the latest research – to be published – from Mohammed Basheer and his colleagues, Sudanese construction engineers and architects said that 80-100 percent of the buildings they designed or implemented included brick.

The GERD, by preventing silts to flow into Sudan, will drastically affect this sector, as most kilns are located along the Blue Nile. Since the operation of the GERD in 2020, data provided by Sudanese officials show that the silt present in the Blue Nile has already greatly reduced. Between 1999 and 2019, the average sediment load in the Blue Nile – measured at Sennar dam – was 166 million tons, but in 2021 the sediment load reached only 24 million tons, according to the researcher Basheer, based on an article which is soon to be published.

To produce the bricks, workers dig holes in the earth to collect the silt on the floodplains. Once the floods come, they open the holes to be filled by sediments. But for two years now, brickmakers noticed that sediments have decreased, according to the recent research. With full operation of the GERD, as the river flow will be regulated and the floods controlled by the dam, the sediment holes will not be submerged by the Nile water anymore.

Bricks industry 3
Bricks industry 4

By blocking the transport of sediment and limiting the flooding of land along the river, GERD will affect the artisanal brick factories on which thousands of Sudanese depend on every day. The future of these young workers from Shendi is uncertain.

The brick industry in Sudan is not a group of huge factories with enough funds to restructure their production or adapt it in a short period of time. Brickmaking relies on about 35,000 workers, dispatched in many local and independent kilns. Among them, about 50 percent live in Khartoum while 38 percent live in the central region, which includes the Gezira state on the Blue Nile. Hindering brickmaking means leaving around 20,000 people jobless, most of them vulnerable.

Urbanization brought many rural people to urban areas where job opportunities are rare, and they often end up finding work on farms or in brick kilns. However, according to Mohammed Basheer, it is hard to evaluate the real effect that the loss of brick production will have on workers. 

“Economy is not linear,” he said. “If the production reduces along the Blue Nile and the main Nile, other regions will increase their production, seeing an opportunity to fill the new demand. Regarding the brick workers, it is hard to evaluate how they will be affected, as many of them could find other work opportunities.”

Nevertheless, it is clear that the positive impacts of silt reduction and flood mitigation will also lead to negative socioeconomic consequences for a portion of the Sudanese population, especially poor urban residents and rural floodplains farmers. These issues will have to be handled by the government in the coming years.

Flood mitigation, a chance for Sudan to fight climate change?

A major argument pushed forward by Ethiopia and Sudan to advocate for the benefits from the GERD is the issue of floods. 

Every year from July to September, heavy rains from the Ethiopian highlands fill the Nile and flow through Sudan. No Sudanese dam has a large enough reservoir to store this water or mitigate the floods. In September 2020, Sudan experienced one of its most violent floods in 100 years. It destroyed more than 100,000 houses, affected more than 875,000 people and killed about 100 people. 

Sudan floods map

With its 74 BCM storage, 10 times the maximum capacity of Roseires dam lake, the GERD could help prevent flooding, especially if the countries cooperate in the dam management.

Sudan 2020 scaled
Sudan 2020 2 scaled

In 2020, Sudan was hit by devastating floods. The human and material tolls were heavy. Sidi Ahmed, a resident of Tuti Island, saw part of his house collapse. The supporters of the dam put forward the mitigation of floods thanks to the regulation of the river flow.

Yet once again, it seems that every positive side effect of the dam has its negative counterpart.

Floods are part of the natural cycle of the Nile, and farmers and families depend on the annual flooding and recession of the river to fertilize their lands. Disappearance of the floods means a loss of fertile lands. Regarding the precedent in Egypt after the building of Aswan High Dam, researchers predict an increase in fertilizers and degraded land fertility.

“Regarding floods, the GERD is not going to end the Nile flood but reduce the occurrence. Taking this into account, we have to think from a human behavioural perspective. There are two components to flood risk: hazard and vulnerability,” said the researcher Mohammed Basheer.

Hazard refers to how often a flood can happen. Vulnerability is the capacity of the population to face a flood. The risk is that if the flow is regulated for several consecutive years, the population would start to build and live on the banks of the river; the years pass and they forget the times when floods exist. After 20 or 30 years, heavier rains than usual compel Ethiopia to let the water flow, and this could flood the banks of the Nile, affecting people who would then be living there.

Mitigating this vulnerability necessitates a joint operation of the GERD and a collaboration between both countries. It also implies a regulation of housing and activities along the Nile in Sudan and urban planification to prevent people from living in risky places.

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Sudan floods 4 scaled

Tuti Island, Sudan – Each year, the island is threatened by floods. The community of the island hopes that thanks to the GERD, the floods will be controlled. In 2020, the island was nearly drowned during the worst floods that occurred in the last 100 years.


Moreover, most of the people affected by floods do not live on the shores of the Blue Nile. If we look at the data on the map above, the danger of floods in Sudan doesn’t come fully from the river, but from rain. While Sennar and Khartoum states bordering the Nile have been badly hit by floods, Northern-Darfur state – which lies far from the river – has also been one of the most affected states. Indeed, riverine floods account for only a part of flooding; the other damages are caused by flash floods coming from the rains, which cannot be mitigated by the dam.

Environmental issues, the great forgotten?

“There is no single study on the impact of the GERD on the environment or on the social environment and the livelihood. This we have been calling for, but it is too late. We are still waiting for an answer to our proposal from the Ministry of Irrigation,” said Dr. Asym Mugrabi, a Sudanese environmentalist who has spent his life working on the Blue Nile.

The narratives on the GERD have always been about the potential gains on Sudan’s economy thanks to the control of the Nile. With a steady flow of the river, Sudan has the opportunity to develop its irrigation potential and increase the hydropower capacity of its dam. But the environmental impacts of such infrastructure in the Blue Nile have not been clearly assessed.

The environment may be affected by the loss of floodplains and silt, according to Dr. Mugraby.

“Each year, the floodplains get submerged by the Blue Nile that brings fertile soil from Ethiopia during the rainy season. When the water recedes, the farmers use these fertile lands to practice recession agriculture. With the GERD, we will lose both silt and floodplains. We will have to use fertilizer to compensate for the loss of fertility due to the loss of silt, but who is going to compensate for these losses?” he said.

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Northern Sudan, 2020: A farmer, Mudasir, plants banana trees in Kerma in the northern part of Sudan. With the GERD, more than 80% of the silt will be stuck in the GERD reservoir, affecting the fertility of Sudanese lands on the banks of the river.
Tuti Island 3 scaled
Tuti Island 2 scaled

Tuti island, Khartoum 2020: In Tuti island, farmers rely on the silt brought by the river from the Ethiopian highlands during the rainy season. The silt carried by the river deposits on the lands of Tuti island during the flood. These silts are vital for the farmers who rely on it to grow crops. Farmers are concerned about their ability to grow crops if the silt gets stuck in the GERD reservoir. 

Analyzing the Aswan High Dam’s consequences on Egypt can shed some light on what Sudan could expect from the GERD. A recent study (Negative Impacts Of Egyptian High Aswan Dam: Lessons For Ethiopia And Sudan) led by Nader Noureldeen Mohamed established a parallel between the repercussions of the Aswan High Dam (AHD) in Egypt and the GERD in Sudan.

The AHD fulfilled Egypt’s electricity needs, improved water access for the population and increased irrigated land. But several negative aspects affected the lands and the communities. In his study, Mohamed wrote that the dam reduced the flow of nutrient-rich sediment downstream, so the lands began to face fertility issues. In response, farmers started to use even more fertilizer and chemicals, which affected the quality of the food produced and the farmers’ health.

Quality of the land and water were affected after these changes occurred. “The increasing use of chemical fertilizers, the disposal of wastes, and changes in land use are the main factors responsible for the progressive increase in nitrate levels in groundwater supplies over the last 20 years,” explained Mohamed in his article. Excess nitrogen is a threat to water quality and one of the main causes of water pollution.

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The sedimentation of Blue Nile before and after GERD. (Belachew Chekene Tesfa 2013)

Despite the necessity to assess the GERD’s environmental impacts, few studies have been conducted. Two French companies were working on environmental impact studies, but their reports were subject to criticism from the parties regarding the baseline to be used to assess the GERD’s impact.

The effect of changes in the river system on biodiversity

One of the main concerns regarding the GERD’s impact is on the fish stock. Any alteration of the waterflow, the temperature, the salinization or the concentration of oxygen will undoubtedly alter the quantity and quality of fish downstream. 

According to the FAO, a marginal portion of the Sudanese GDP comes from fishing. Just 13,686 people were reported being engaged in inland fishing in 2017, most of them centered around the Nile River and its tributaries, seasonal floodplains, territorial waters and the Red Sea.

Any change in the Nile river system, however, will have a direct impact on the fish stocks. While the GERD will reduce the Blue Nile floods and the silt carried by the river, many species living in the river rely on the regular annual floods.

“Fish productivity is synchronized with annual floods. The floodplains are nurseries for the fish, but with the GERD, there would be no floodplains,” asserts Dr. Mugraby.

No clear studies have been conducted to assess how the control of floods and silt might affect the Blue Nile ecosystem. Floods are linked to water quality and quantity; they bring silt that changes the water chemistry and provides habitats for aquatic species. A lack of sediment is therefore an important concern regarding the river ecosystem. Without sediment transport and deposition, new habitats cannot be formed, and without some nutrient enrichment carried by the sediment, submerged vegetation cannot grow. Too little sediment can alter an ecosystem to the point that native species cannot survive.

Also, the GERD reservoir will block fish migration along the river. Increasing water discharge will further affect the fish stocks downstream, and the disappearance of the floodplains means the disappearance of breeding sites all along the river.

©Arthur Larie 4 scaled
©Arthur Larie 6

Roseires Lake fishermen are concerned about the effects of the dam on the fishery ecosystem. Many environmentalists such as Assim Moghrani consider that such a hydroelectric structure will have a negative impact on the fisheries. To date, no major environmental impact studies have been conducted to anticipate the effect of the GERD on the downstream Blue Nile ecosystem.

Oxygen levels in the water will also change, as the GERD will release huge quantities of water without oxygen. 

Water is oxygenated when in contact with the atmosphere. The maximal depth for oxygenated water can vary, but according to professors Assim and Basheer, below 20 meters the water will not receive oxygen from the surface or ray lights. As the GERD reservoir has a maximum water depth of 140 meters, this means about 85 percent of the water stored behind the dam will not be oxygenated.

This would not be an issue if only the top water was released to produce electricity, but water will also be released from the bottom outlets, spreading non-oxygenated water in the Sudanese Blue Nile. Many fish species need a certain concentration of oxygen to live and breed in the river. Below this rate, fish mortality can increase, and invertebrates and other small organisms may also be affected.

The same claim was raised regarding the water temperature. The water lying 140 meters deep will be much colder than the temperature of the current stream. For environmentalist Assim Moghrane, it is evident that this will alter the living condition, breeding cycle and plant photosynthesis, but exact potential impacts have not been assessed.

Professor Assim and other Sudanese researchers are advocating for a comprehensive impact study that could evaluate the risk of the GERD on biodiversity and the environment.

Researchers interviewed for this investigation regret the lack of impact studies on the environment. On the Sudanese side, people do not know what to expect or how to be prepared to try to mitigate the potential negative environmental consequences. 

No matter what, it is clear that impacts will come, according to Dr. Mugraby.

“Anything that happens in the GERD would have immediate consequences on Sudan – positive or negative,” he said.

Reporting: Bastien Massa and Arthur Larie

Editing: Annika McGinnis

Photography: Bastien Massa and Arthur Larie

Videography:  Bastien Massa and Arthur Larie

Data Visualization: Primrose Natukunda

Graphics: Jonathan Kabugo

Communications: Delicate Sive and Curity Ogada 

Design and IT Support: Mukalele Rogers and Delicate Sive.

Project Coordination: Annika McGinnis and Fredrick Mugira