A very long Nile, or 6,650 km of problems

Who owns the water of the Nile and what is its most dangerous inhabitant? Most of us know very little about the world’s longest river, and it’s high time to change that. Especially since, according to scientists, the Nile is shrinking with each passing decade, while the lives and well-being of more than 300 million Africans depend on its waters.

The first problem? Even the question of whether the Nile is actually the world’s longest river is still in dispute. In 2007, a theory emerged that the source of the Amazon is located about 100 km farther upstream than previously believed, making the Brazilian river the rightful holder of the “longest” title. So far, however, this has not been officially confirmed.

The curse of the flatworm

Regardless of its global ranking, the Nile is undeniably an impressively long river. From its source in western Tanzania, it flows through 11 African countries before emptying into the Mediterranean Sea in Egypt. For local communities, it is a lifeline – a source of water, a place to bathe, and a fishing ground. Unfortunately, it also harbors danger, and contrary to popular belief, it’s not the crocodile, but… the snail.

Freshwater snail species commonly found in the Nile are responsible for spreading blood flukes –flatworms that parasitize humans and cause a serious disease called schistosomiasis. In Egypt, the problem primarily affects the Nile Delta and the Cairo area, and in 2017, as many as 6 million people required treatment. Across Sub-Saharan Africa, over 200 million people are infected, and the healthcare costs are enormous. The urogenital form of schistosomiasis is associated with an increased risk of bladder cancer.

The Egyptian government, in cooperation with the World Health Organization, has been implementing a control program for these dangerous parasites for 10 years, but infections continue to be reported, including in the upper reaches of the Nile – especially in Uganda and Sudan.

The great dam of African discord

Devious parasites and rising levels of heavy metal pollution, which we covered in Water Matters two years ago, are not the only problems faced by the residents of Africa’s largest river basin. In recent years, the most controversy has surrounded the construction of the Grand Ethiopian Renaissance Dam, or GERD. This $5 billion megaproject began in 2011, with a ceremonial opening scheduled for the second half of 2025.

The dam is located on the Nile, 14 km from the Sudanese border, and is set to become the largest hydropower plant in all of Africa, with a capacity of over 5,000 MW. Its accompanying reservoir can hold 74 billion cubic meters of water – twice as much as the Hoover Dam in the U.S. Holding back such a volume of water will affect Nile flows in Sudan and Egypt, sparking international controversy.

Egypt accuses Ethiopia of violating international law, arguing that the filling of the reservoir – which began in 2020 – deprives it of drinking and irrigation water and limits energy production at Egypt’s own dam, the Aswan High Dam. The media have already reported talk of possible military intervention to resolve the dispute.

More rain, less water?

Disputes over Nile water are likely to intensify with ongoing climate change. African scientists are increasingly concerned about the declining average river flow – from 3,000 m³/s in the 1970s to 2,830 m³/s today.

According to research by American scientists, even though climate models predict an overall increase in rainfall in the Nile’s upper catchment area, the frequency of extremely hot and dry years may rise by 1.5 to 3 times by the end of the 21st century. This will increase evaporation and accelerate the river’s decline. By 2040, up to 45% of basin residents may face water shortages.

The Nile, which for millennia served as a vital artery of life, is slowly becoming a symbol of Africa’s water crisis. Its consequences will be crucial not only for hundreds of millions of people but also for more than 800 species of fish, as well as numerous amphibians, reptiles, and birds – an essential part of Africa’s natural wealth.