Its course is entirely contained within the boundaries of Ethiopia and empties into a chain of interconnected lakes that begin with Lake Gargori and end with Lake Abbe or Abhe Bad on the border with Djibouti , some kilometres 60 or 70 miles from the head of the Gulf of Tadjoura. The Awash River is the principal stream of an endorheic drainage basin covering parts of the Amhara , Oromia and Somali Regions , as well as the southern half of the Afar Region.
The basin usually has two rainy seasons, a shorter one around March Belg , and a longer one between June and September Kiremt , which partly fall into one longer rainy season. Climate change is predicted to increase the water deficiency in all seasons and for parts of the basin, due to a projected increase in temperature and decrease in precipitation.
The main sources of water pollution in the upper Awash River basin come from industrial and urban wastes, agricultural runoff pesticides , fertilizers , and sewage discharge. Polluting industries in the Awash River basin include tanneries , paint factories, slaughterhouses , textiles , breweries , soft drink factories, sugar factories, hospitals, and pharmaceuticals.
The Awash Valley and especially the Middle Awash is internationally famous for its high density of hominin fossils, offering unparalleled insight into the early evolution of humans. The Awash River is 1, kilometres long.
After entering the bottom of the Great Rift Valley , the Awash flows south to loop around Mount Zuqualla in an easterly then northeasterly direction, before entering Koka Reservoir. There, water is used for the irrigation of sugar cane plantations. Towns and cities along its course include Metehara , Awash , Gewane and Asaita. There are tributary rivers, lakes, hot springs , and swamps in the Middle Awash Basin. The rainy season tends to be bimodal towards eastern Ethiopia and almost unimodal towards western Ethiopia.
