Adamawa Plateau
The Bénoué River (Benue) serves as the North's primary waterway, as it passes through the port at Garoua. It flows down from the Adamawa Plateau and is enlarged by the Mayo Rey, the Mayo Kebi (which flows into the area from Chad), the Mayo Louti (which flows down from the Mandara mountains) and other rivers. Its valley forms the main part of the Bénoué Depression. Several smaller tributaries also flow into the Bénoué. All of these waterways form part of the Niger basin.