White Nile
The hydrology of the eastern part of South Sudan is complicated by the Sudd, a vast area of marshland into which many rivers flow and lose their identity. Much of the water entering the Sudd is lost to evaporation, but much ultimately drains to the White Nile. Ninety percent of South Sudan lies in the White Nile basin The three major cities of South Sudan are all located on the White Nile or a major tributary.