Water politics in the Nile Basin share the river – Egypt, Sudan, Ethiopia, Uganda, Kenya, Tanzania, Burundi, Rwanda and the Democratic Republic of Congo with Eritrea as an observer. During the colonial period, Britain effectively controlled the Nile through its military presence in Africa. Since Sudanese independence, Sudan has renegotiated with Egypt over the use of the Nile waters. The 1959 agreement between Sudan and Egypt allocated the entire average annual flow of the Nile to be shared among the Sudan and Egypt at 18.5 and 55.5 billion cubic meters respectively, but ignored the rights to water of the remaining eight Nile countries. Ethiopia contributes 80%
Cataracts of the Nile river bed exposed. These distinctive features of the river between Aswan and Khartoum have led to the stretch being often referred to as the Cataract Nile, while the downstream portion is occasionally referred to as the "Egyptian" Nile. The geological distinction between these two portions of the river is considerable. North of Aswan, the river bed is not rocky, but is instead composed of sediment, and far from being a shallow river, it is believed that the bedrock was previously eroded to be several thousand feet deep. This created a vast canyon that is now filled by the sediment, some