Kagera

The Kagera river, also known as the Akagera River or the Alexandra Nile, is an East African river that is part of the Nile's upper headwaters and transports water from the Nile's farthest source. The Kagera part of the river starts in Burundi and flows out of Lake Rweru. It runs east from the lake, crossing the Rwanda-Burundi and Rwanda-Tanzania borders before joining the Ruvubu River. Two important tributaries, the Nyabarongo of Rwanda, which feeds Lake Rweru, and the Ruvubu of Burundi, give water for the Kagera. It is unclear which of these two feeder rivers is the longer, and thus the Nile's ultimate source.

The Kagera flows north from the junction along the Rwanda-Tanzania border, past Rusumo Falls, and through Akagera National Park. It then flows east, following the Tanzania-Uganda border and draining into Uganda's Lake Victoria. Richard Kandt found the Kagera's source in 1898.

The river has played a significant role in the histories of the nations through which it flows, particularly Rwanda. The Rwandan colonial era began in 1894 when German Gustav Adolf von Gotzen crossed the Kagera at Rusumo Falls, then the Belgians fought the Germans in 1916 during World War I, entering Rwanda by the same path. In 1994, the river drew international attention for transporting dead from the Rwandan genocide into Lake Victoria, prompting the declaration of a state of emergency in sections of Uganda where the bodies eventually washed up.

Length: 249 miles (shared with Burundi, Rwanda, and Tanzania)