However, during the rainy season (generally July to October), the Atbarah rises some 18 ft (5 m) above its normal level.

At this time, it forms a formidable barrier between the northern and central districts of the Amhara Region of Ethiopia.

Besides the Tekezé, other important tributaries of the Atbarah include the Shinfa River which rises west of Lake Tana, and the Greater Angereb which has its source north of the city of Gondar.

[1] Other ancient authors mentioning the name include Agatharchides, who called it Astabaras (Greek: Ασταβάρας),[1] and Ptolemy (Geography 4.7).

[1] Pliny the Elder provides a slightly different etymology of Astaboras, stating that "in the language of the local people" the name means "water coming from the shades below" (N.H. 5.10).