Rapid filling of the Grand Ethiopian Renaissance Dam at the headwaters of the Nile River could reduce water supplies to downstream Egypt by more than one-third, new research from the University of Southern California (USC) shows.
This river is the world’s biggest waterway. Some 280 million people in 11 countries in the basin depend on the waterway – a primary source of irrigation for more than 5,000 years. A water deficit of that magnitude, if unmitigated, could destabilize a politically volatile part of the world by reducing arable land in Egypt by up to 72%. The study projects that economic losses to agriculture would reach $51 billion. The gross domestic product loss would push unemployment to 24%.
“Our study forecasts dire water supply impacts downstream, causing what would be the largest water stress dispute in modern human history,” said Essam Heggy, a research scientist at the USC Viterbi School of Engineering and lead author of the study. “Averaging losses from all of the announced filling scenarios, these water shortages could nearly double Egypt’s present water supply deficit and will have dire consequences for Egypt’s economy, employment, migration and food supply.”
The study was published July 1 in Environmental Research Letters.
The study offers policy solutions for sustainability that could potentially minimize the downstream impacts and reduce tensions. For example, the impacts could be partially offset by adjusting operations at Aswan Dam downstream in southern Egypt, pumping more groundwater, cultivating different crops and improving irrigation systems.
Ethiopia’s $5 billion Grand Ethiopian Renaissance Dam, which is nearing completion at the Nile headwaters, is in the second phase of filling. It will be the largest hydropower project in Africa at 6,450 MW and would create a reservoir containing 74 billion cubic meters of water.
It will take years to fill, and the water diversions could have devastating impacts downstream. Egypt and Sudan have water rights to the Nile, while Ethiopia was not allocated a quantifiable share. But as water and energy demand grows in the Nile River basin, Ethiopia is asserting its needs for hydropower and irrigated agriculture to promote development.
Egypt relies on the Nile for more than 90% of its water. The region’s population could increase by 25% in 30 years, increasing demand at a time when Egypt would expect less water. Water rights along the Nile have been in dispute since 1959.
The USC study examined various dam filling scenarios and water shortage impacts for Egypt. Based on the short-term filling strategies of three to five years, presently favored by Ethiopia, the water deficit downstream in Egypt could almost double. Of the additional water loss, 83% would be due to dam restraining flow and evaporation and 17% due to seepage into rocks and sand.
The study helps fill a gap in the dispute by reducing ambiguities about how dam filling scenarios would impact the water budget deficit in Egypt, as well as offering a feasibility index to the potential solutions. As both global warming and aridification accelerate, it underscores the need for more water research in arid lands.
“There is a real need for sound science to resolve the ambiguity surrounding this controversy,” Heggy said. “Our analysis doesn’t point fingers yet it shows a dire water situation that will result downstream, which is forecasted as the largest water stress dispute in human history. It can be avoided if proper support is made to the water, energy and environment research in the Nile basin.”
So far, despite international negotiations, there’s been little progress in the decade-long dispute.
The study comes amidst a 10-year dispute between Egypt and Ethiopia over water supply on the Nile River. The parties seek an international solution, yet talks led by the U.S. State Department – and joined by the European Union and the United Nations – have resulted in little agreement after four years.
Meanwhile, Egypt has vowed not to allow the dam to impede its water supply, and it held joint military maneuvers with Sudan in May. Sudan has since petitioned the UN Security Council to hold an emergency session as soon as possible.
Heggy said it’s possible a win-win solution may yet be found for the Nile River, based on policy options the study identifies. Progress has been impeded, however, due to a lack of credible information about downstream water supply and economic impacts. Getting an agreement will likely require better data and forecasts on impacts to human society, as well as ecological effects along the Nile.
The research was funded by the James H. Zumberge Research and Innovation Fund allocation to the Arid Climates and Water Research Center at USC Viterbi.
