Kainji dam is located in Borgu LGA of Niger State. Kainji Dam comprises the civil dam structure, the gated spillway, the hydroelectric turbine and generators, and a navigation lock, with monitoring and control systems to all these.
Kainji powerhouse is equipped with eight turbine-alternator groups including four Kaplan type rated at 80 MW, two turbines also Kaplan type rated at 100 MW and two propeller turbines rated at120 MW. The available head ranges between 23.8 m and 41.2 m according to the water level in the reservoir. Provision was made for a further four turbines in the dam structure but these were never installed.
The development perimeter comprises the main concrete gravity dam with earth embanked dams on either side of the main and saddle dams, which closes a secondary valley, and two gates. The main dam is 550m long with a maximum height of 64m. It comprises the water intakes, the flood evacuator and the abutments. The powerhouse is located downstream of the dam, on the right bank, and at right angles to the water intakes. The reservoir, which presently forms the Lake Kainji, is 136 km long and has a capacity of 15 billion m³.
The dam stores and safely releases water to generate hydroelectric power, provide flood protection and, originally, support navigation.