From the coast, and further inland is Dolo at the confluence of the Daua and Ganale to form the Juba.
Of the three headstreams, the Web, the Ganale and the Daua, the Ganale (or Ganana) is the central river and the true upper course of the Juba.
Leaving the higher mountains in about 5° 15' N., 40° E., the Ganale enters a large slightly undulating grass plain which extends south of the valley of the Daua and occupies all the country eastward to the junction of the two rivers.
Lower down the Daua enters on the right bank.
The Daua (or Dawa) is formed by the mountain torrents which have their rise S.
In its middle course the Daua has cut a deep narrowvalley through the plain; lower down it bends N.E.
The river is not deep and can be forded in many places; the banks are fringed with thick bush and dom-palms. At the junction of the Ganale and the Web the river is swift-flowing and 85 yards across; just below the Daua confluence it is 200 yds.
Below the Daua the river, now known as the Juba, receives no tributary of importance.
The river, from its mouth to the confluence of the Daua and Ganale, forms the frontier between the British East Africa protectorate and Italian Somaliland; and from that point to about 4° 20' N.
The Daua is the boundary between British and Abyssinian territory.