Kainji Dam , Nigeria

Kainji dam is located in Borgu LGA, Niger State of Central Nigeria. The dam is across the Niger River. The dam was built between 1964 and 1968 by the Italian civil engineering contractor consortium Impregilo, following designs by Joint Consultants Balfour Beatty and Nedeco. The Dam comprises the civil dam structure, the gated spillway, the hydroelectric turbine and generators, and a single navigation lock chamber, with monitoring and control systems to all these. The lock also has the ability to lift barges 49 metres (161 feet). Kainji dam was formally opened in 1969. People displaced by the construction of the dam and its reservoir, Kainji Lake were resettled and compensated adequately.

 

How was Kainji Dam constructed?

The Kainji dam was one of Nigeria’s biggest infrastructure undertakings at the time. Engineers strengthened bridges and roads along a 1,000-kilometer route as part of the scheme’s preparation work so that large machinery and other equipment could be transported to the building site. Kanji is a gravity dam and as such primarily uses the weight of the dam alone to hold back the water pushing against the structure. It was mainly constructed from concrete. The structure was built using more than 25,000 tonnes of steel and over 250,000 tonnes of cement by engineers. The cement was transported in specially built bulk carrier vessels from Norway and Nigerian businesses. The purpose of the concrete construction was to facilitate navigation along the Niger upstream to the town of Yelwa in Kebbi state and to supply electricity to Nigeria. Around 50,000 people were displaced by the scheme—mostly Reshe (Gungunci, Gungawa), Busa (Busawa, Bussangi), Kamberi, Nupe, Lopawa, and Laro. Resettlement work saw 128 villages and 2 new townships built, as well as perimeter roads around the reservoir.

 

Measurements of the Dam

Kainji dam is the largest dam on the river Niger – the third longest river in Africa, the principal river in western Africa and one of the longest dams in the world. The dam is 72metres high and 7.2kilometres long. The entire length of the dam, including its saddle dam that seals off a tributary valley, is approximately 10 kilometres (6.2 miles). There is a major segment that spans 550 metres (1,800 feet) across the outflow to the Niger. The middle piece of the structure, which houses the hydroelectric turbines, was constructed out of concrete, but the majority of it is composed of earth. This section is 65 metres (213 feet) high.

 

The Hydroelectric power station

The dam was designed to have a generating capacity of 960 megawatts (1,290,000 horsepower); however, Its present capacity is lower as only 8 of the planned 12 turbines were installed, reducing the capacity to 760 megawatts (1,020,000 horsepower). The 8 installed turbine-alternator groups includes 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. All of Nigeria’s major cities receive their electricity from the dam, yet not to the anticipated amounts as some portions of the electricity is sold to Niger, a bordering nation. Furthermore, the Niger’s water flow has become unpredictable due to sporadic droughts, which reduces the dam’s electrical output.

 

Kainji hydroelectric dam

Kainji dam is a 7.2 km long gravity dam on the River Niger. It created Lake kainji, which is at 135km long and 30km wide at its widest point, is the largest man-made lake in Nigeria. The lake provides fishing and allows farming all year, however in times of rainfall the dam releases water which can flood and submerge farmlands.

 

Lake Kainji

The Kainji Lake is on the border between Niger and Kebbi states, in north-western Nigeria. It encompasses 500 square miles (1,300 km2) and was created in 1968 as a result of the building of the Kainji Dam. The Lake, which is approximately 135 kilometres (84 miles) long and 30 kilometres (19 miles) wide at its widest point, has been utilised for both irrigation and fishing. There have been several incidents of flooding as a result of uncoordinated opening of the floodgates. The 1998/99 flood incident affected about 60 villages along the river banks. In one of the incidents, the lake completely submerged Foge Island in the Niger River, the town of Bussa, and other riverine settlements; part of the old town of Yelwa (the seat of Yauri emirate) was also permanently flooded. Numerous farms were washed away, domestic animals drowned, and dikes were destroyed. Officials in charge of the dam faced criticism for starting too late and pouring too much water out too quickly. The Borgu and Zugurma game reserves are located in Kainji Lake National Park, which spans 2,062 square miles [5,341 square km] and is home to a variety of wildlife species, including baboons, duikers, hippopotamuses, hyenas, kobs, roans, and warthogs.

 

Benefits

• The dam improved irrigation for farmers and strengthened agricultural industries in the region.
• It generates hydroelectricity that serves almost the whole nation.
• It improved river navigation upstream to Yelwa in Kebbi state and control the Niger’s waters downstream to the point the Niger meets the river Kaduna (confluence between the two rivers)
• Kainji Lake – the largest man-made lake in Nigeria – was created when the dam was built. It provides water for fishing, an important industry in the area.