The Sokoto River (formerly known as Gublin Kebbi) is a river in north-west Nigeria and a tributary of the River Niger. The river's source is near Funtua in the south of Katsina State, some in a straight line from Sokoto. It flows north-west passing Gusau in Zamfara State, where the Gusau Dam forms a reservoir that supplies the city with water. Further downstream the river enters Sokoto State where it passes by Sokoto and is joined by the Rima River, then turning south and flowing through Birnin Kebbi in Kebbi State. About south of Birnin Kebbi, it reaches its confluence with the Niger River.