The study predicts water supplies and economic risks as tensions surrounding the Grand Ethiopian Renaissance Dam. increase

Rapidly filling a huge dam on the upper reaches of the Nile – the world’s largest waterway serving millions of people – could cut water supplies downstream from Egypt by more than a third, new USC research shows.

A water deficit of this magnitude, if not mitigated, could potentially destabilize a politically unstable part of the world by reducing arable land in Egypt by up to 72%. The study predicts economic losses to agriculture would reach $ 51 billion. The loss of gross domestic product would raise unemployment to 24%, displace many people and disrupt the economy.

“Our study predicts devastating effects on downstream water supplies, which would spark the greatest water stress controversy in modern human history,” said Essam Heggy, researcher at USC Viterbi School of Engineering and lead author of the study. “With average losses from all announced filling scenarios, this water shortage could almost double Egypt’s current water supply deficit and will have devastating consequences for Egypt’s economy, employment, migration and food supply.”

The study was started on July 1 in. released Environmental research letters.

Despite the risks, the study offers policy solutions for sustainability that could potentially minimize the impact downstream and reduce tensions in the Nile region. For example, the effects could be partially offset by adjusting operations at the Aswan Dam downstream in southern Egypt, pumping more groundwater, growing different types of plants and improving irrigation systems.

Despite international negotiations, the decades-long dispute has so far made little progress.

At the heart of the controversy is Ethiopia’s $ 5 billion large Ethiopian Renaissance Dam, which is nearing completion on the upper reaches of the Nile. Now in the second filling phase, it will be the largest hydropower project in Africa and create a reservoir with 74 billion cubic meters of water – more than double the operating capacity of Lake Mead on the Colorado River.

It’s so big it will take years to fill, and depending on how long it takes, the water diversions downstream can be devastating. Egypt and Sudan have water rights on the Nile, while Ethiopia has not been allocated a quantifiable share. But while water and energy needs in the Nile Basin grow, Ethiopia reaffirms its need for hydropower and irrigated agriculture to fuel development.

Around 280 million people in 11 countries in the basin depend on the waterway – a major source of irrigation for more than 5,000 years. Egypt gets more than 90% of its water from the Nile. The region’s population could increase by 25% in 30 years, which would increase demand at a time when Egypt would expect less water from the Nile. The water rights along the Nile have been controversial since 1959; today the conflict threatens to escalate into war.

The USC study examined various dam filling scenarios and the effects of water scarcity on Egypt. Based on the short-term fill strategies of 3 to 5 years currently favored by Ethiopia, the water deficit downstream in Egypt could almost double; 83% of the additional water loss would be caused by the dam, which restricts flow and evaporation, and 17% of the additional water loss would be lost through penetration into rocks and sand.

The study helps fill a gap in the dispute by reducing confusion about how dam filling scenarios would affect the water balance deficit in Egypt and providing a feasibility index for the various possible solutions. Increasing global warming and dehydration underscores the need for more water research in arid areas, which is the core task of the Arid Climates and Water Research Center at the USC Viterbi School of Engineering.

“There is a real need for sound science to resolve the ambiguity of this controversy,” said Heggy. “Our analysis does not point the finger, but shows a dire water situation that will arise downstream in what is predicted to be the greatest controversy over water stress in human history. It can be avoided if water, energy and environmental research in the Nile Basin is adequately supported. “

The study takes place amid a ten-year dispute between Egypt and Ethiopia over the Nile’s water supply. The parties are looking for an international solution, but talks led by the US State Department – which the European Union and the United Nations have joined – have produced little agreement after four years.

Meanwhile, tensions are high as negotiators seek to avert armed conflict. Egypt vowed not to allow the dam to obstruct its water supply and conducted joint military maneuvers with Sudan in May. Sudan has since asked the United Nations Security Council to hold an emergency meeting as soon as possible.

The dispute exemplifies wider disputes over water scarcity as climate change affects fast-growing developing countries. Disputes along the Mekong, Zambezi and Tigris rivers, among others, show the potential for political instability and conflict.

Heggy said it was possible that a win-win solution for the Nile could still be found based on the policy options identified in the study. However, progress has been hampered by the lack of credible information on the downstream water supply and economic impact. Reaching an agreement is likely to require better data and forecasts on the impacts on human society, as well as the environmental impacts along the Nile.


Co-authors of the study are Heggy Abotalib, Z. Abotalib from USC and Zane Sharkawy from Cornell University.

The research was funded by the James H. Zumberge Research and Innovation Fund to the Viterbi School of Engineering’s Dry Climate and Water Research Center.


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