The Nile is the world‘s longest river. It flows 6,600 km, traversing more than 35° of latitude and drains an area of about 3.1 million km2, one tenth of the African continent. The principal streams are the White Nile, which begins in the Great Lakes region of Central Africa; and the Blue Nile and the Atbara, both flowing from the highlands of Ethiopia. The Nile‘s most distant source is the Kagera River, which flows from Burundi through Rwanda and Tanzania into Lake Victoria.
The total area of open water in the Nile basin is about 90,000 km2, a vast area but less than 3 percent of the basin‘s total area. Lake Victoria, the world’s second largest freshwater lake, is by far the largest lake at 69,000 km2, followed by the three other major lakes of the East African Rift Valley, Lake Albert, Kyoga and Edward. The basins of Lake Victoria and the three smaller lakes to the west Lake George, Edward and Albert are rich with floodplains, wetlands and smaller satellite lakes that support an abundant diversity of animals and plants and many water-dependent ecosystems.
Downstream from the source of the Blue Nile, Lake Tana has a surface area of 3,200 km2, and the lakes of the Nile Delta cover a further 2,400 km2. Man-made lakes are a significant feature of the lower reaches of the Nile, where Lake Nasser (Lake Nubia) has a potential area of 4,200 km2, making it the world‘s second largest artificial lake.