It provides 90 percent of the water flowing into Lake Chad. The watershed of the river covers 548,747 square kilometres (211,872 sq mi). The principal tributary is the Logone River, while minor tributaries include the Bahr Salamat, the Bahr Sarh (Ouham River), the Bahr Aouk and the Bahr Kéita.
Much of Chad's population, including Sarh and the capital N'Djamena, is concentrated around it.
The river supports an important local fishing industry. One of the most highly prized local fishes is the Nile Perch.