Nile river
A fertile area of the Nile.Kenneth Garrett/Getty Images

The fresh-water supply to Egypt's Nile delta has been dramatically reduced in recent year, putting the country at risk of serious water and food shortages in the next decade, scientists have warned. The construction of the Grand Ethiopian Renaissance Dam is expected to worsen the situation even more.

Egypt's population has exploded in recent years, reaching nearly 90 million, exacerbating social tensions and accelerating the depletion of resources.

About 70% of water flow reaching Egypt is derived from the Blue Nile and Atbara River, both sourced in Ethiopia. Over the past 200 years, expanding population and resulting increased human activity have seriously altered flow conditions of the Nile.

In an article published by the Geological Society of America, scientists have suggested that the water available for the inhabitants of Egypt – of the Lower Nile Valley and Delta region in particular – is continuously being reduced. This creates a situation where fertile lands are threatened and food shortages could be observed in the future.

The scientists thus say that a Blue Nile water crisis is looming.

Different threats

The study shows that the delta is no longer able to function as a naturally expanding fluvial-coastal centre, due to human pressure. Less than 10% of Nile river water now reaches the sea, while most of the nutrient-rich sediments remain trapped in the delta by a dense canal and irrigation system. This means that cultivated lands in the delta may become characterised by nutrient-poor soils, with a decreased ability to grow food.

Another threat is the fact that sea levels are rising at a rate of about 3 mm per year but at the same time, the coastal delta margin is being lowered. This leads to saline intrusion now reaching agricultural terrains in central delta sectors. The scientists estimate that the coastal 20 to 40 km of delta surface will be underwater by the end of this century, with less land available for agriculture.

But perhaps the most significant threat is the construction by Ethiopia of the Grand Ethiopian Renaissance Dam, which will be completed by 2017. As the large reservoir behind the dam is filled, it is believed that the Nile flow from Ethiopia to Egypt and its delta will be further reduced.

"It is expected that problems of fresh water and energy poverty in the lower Nile Basin are likely to be seriously exacerbated in years ahead by construction of Ethiopia's Grand Renaissance Dam", the scientists say.

The impact of dams on Nile flows has been seen before. For instance, the construction the Aswan Low Dam in 1902, and the Aswan High Dam in 1965 has altered water the flow and distribution of nourishing organic-rich soil in the delta.

The scientists call for a form of arbitration by regional or global bodies, to reduce the threats on Egypt and make sure its population can have a sustainable access to water from the Blue Nile in the future.