The river does not normally enter the Indian Ocean, but into a depression area, where it is finally lost in the sand in southern Somalia. Only with exceptionally heavy rains does the Shabelle River break through to join the Juba and thus succeed in reaching the ocean. With an average annual rainfall of 455 mm and much higher potential evaporation, mean annual runoff of the Shabelle River at Belet-Weyne is 2 384 million m3. Over 90% of the runoff are generated by catchments within Ethiopia. As the river crosses the existing international border between Ethiopia and Somalia, the Somali City of Belet-Weyne is the most important point where the river flow and its water quality could be observed in Somalia. The river has a high saline content even during high flows.
Like the Shabelle, the Juba River originates from the Ethiopian Highlands, where three large tributaries, the Gestro, the Genale and Dawa meet near the border with Somalia to form the Juba River. The rainfall at the source reach 1500 mm/y, dramatically decreasing southwards and the mean is 550 mm. Luuq, a Somali town, is the most important point to observe the Juba River as it crosses the border. The Juba, which enters the Indian Ocean at Kismayo City, has a total length of 1100 km, 550 km of which in Somalia. The mean annual runoff at Luuq is 6 400 million m3; Ethiopia again contributes over 90 %. Kenya, as there are no tributaries originating there, does not normally contribute to the Juba, and has no access to the main river thus any significant interests.