In Nigeria, dams and reservoirs serve multiple purposes, including but not limited to agriculture, water supply, and hydroelectric power generation. Especially in the arid north, where precipitation is scarce, they are crucial. The Niger Dams Project consists of three dams and reservoirs constructed on the Niger and Kaduna rivers in the latter half of the twentieth century in Kwara, Niger, and Kebbi in northwest Nigeria. The first of the dams were erected at Kainji in 1969. The states around Kainji Lake rely on it as a reservoir for irrigation and fishing initiatives. The tourism business on the lake’s western coast has been boosted by Lake Kainji National Park, which features the Borgu and Zugurma game reserves. Dam construction at Jebba and the accompanying hydroelectric power plant was finished 103 kilometres (64 miles) from the Kainji Dam in 1984, and dam construction at Shiroro Gorge on the Kaduna River, west of Bida in Niger state, was completed and put into operation in 1990.
Research showed that 323 different dams of varying sizes have been built and are currently in use across Nigeria. Their combined volume is more significant than 30109 m3 in the Sudano-Sahelian region, where 85% of the country’s more significant dams are situated. Seventy-nine per cent contain domestic and industrial water supply components, while 33% have irrigation as a primary purpose to which the stored water is placed; 29% are for fisheries, 16% for recreation and 4% for hydroelectric power generation (HEP). The water levels of the Niger and Kaduna rivers are regulated by the three major hydropower dams currently operational. The combined operating capacity of the Kainji, Jebba, and Shiroro dams is 18.6 billion cubic metres (660 billion cubic feet), and their combined power capacity is 1920 MW. Nigeria’s dams can be classified into several categories: structure, age, purpose, etc. Small dams dominate, with medium dams in second place and huge dams in third place. This is because of the high price, high demand, and limited supply of suitable land for such developments. Dams in Nigeria can be found in the northwest, the northeast, the centre, the south, the southeast, and the southernmost regions of the country. Due to neglect, several of these dams have experienced failures in recent years, both operationally and structurally. Conclusions Land availability, purpose, water need, ecological variables, and government policy were identified as essential determinants in the siting of dams in Nigeria.
Ede-Erinle Reservoir (Osun State)
The Erinle River is a tributary of the Osun River in Osun State, Nigeria, entering from the north near Ede just below the Ede Dam. The new Erinle Dam is upstream. Two dams supply Osogbo with water. Untreated and treated water pose health risks. Erinle was a Yoruba hunter-turned-orisha. He is claimed to have led the first Olobu of Ilobu to Ilobu and safeguarded the town from Fulani attacks. He’s a hunter, herbalist, and farmer. Legend says that he sank into the ground near Ilobu and became a river. He is well-known across Yorùbáland. Erinle’s cult is located in Oyo Empire towns. His shrines have Erinle River stones. The name may come from Erin and il or Erin and ile (house). South of Offa, the Erinle River begins. It and the Oba River, which springs north of Ogbomosho, are Osun River tributaries. Both residential, commercial, and industrial locations along the Erinle River produced untreated garbage in 2012. Farm fertilisers and pesticides polluted it. Old and new dams on the river feed Osogbo, the state capital, with water. Malaria and diarrhoea are common in Osogbo, especially in high-density residential areas with public tap water.
Asejire Reservoir (Oyo State)
About 30 kilometres east of Ibadan, you’ll find the Asejire Reservoir in Oyo State in southwestern Nigeria on the Osun River. The watershed region is entirely off-limits for agricultural use, and trees have been planted along the riverbanks to prevent erosion and siltation from occurring. In the late 1960s, construction began on the reservoir. Because there is an abundant water supply, the reservoir stays full throughout the year. Raw water is drawn from the reservoir and delivered to the Ibadan water treatment plants at Asejire and Osegere. The water supply project was finished in 1972, and it has a capacity of approximately 80 million litres per day; of this amount, roughly 80 per cent is used for uses within the home.
Bakolori Dam (Sokoto State)
Bakolori Dam is in Nigeria’s Sokoto State. The reservoir was full by 1981. It’s a significant reservoir on the Sokoto River, which feeds the Niger River. The dam delivers water to Bakolori Irrigation. The dam’s 8,000-hectare reservoir extends 19 km upstream. Many peasant farmers were displaced by dam building without compensation. Many people died in protests against job loss. The project is a classic failure. The Sokoto River flows through northern Nigeria’s Sudan Savannah. June–September annual rainfall ranges from 500 to 1,300 mm. Before the dam was built, roughly 50,000 farmers grew rice and sorghum in the rainy season and onions, garlic, and tomatoes in the dry. Shadoof farmers lifted river water for irrigation channels or ponds. Purdah women don’t work in the field but have ownership rights and help the process—non-secluded women’s farms. Most lands were owned communally without proper records. Subsistence farmers in the area feared risk more than profit. The demand for a stable water supply was one reason for building the dam.
Challawa Gorge Dam (Kano State)
Challawa Gorge Dam is located in Kano State, 90 km southwest of Kano city. It’s a significant reservoir on the Challawa River, a tributary of the Hadejia River’s Kano River. Kano State’s Water Resources and Engineering Construction Agency launched the Challawa Gorge reservoir project, but the Federal Government funded it. The dam is owned and administered by a federal agency. Julius Berger Nigeria completed the rock-fill dam in 1990-1992. It is 42 metres high and 7.8 kilometres long. The dam holds 904,000,000 m3. The watershed is 3857 km2. The dam was built to generate hydropower and may have a 3MW average capacity – more in the rainy season and less in the dry. However, delivering the power would cost far more than current retail pricing, and how to finance the project needs to be clarified.
Dadin Kowa Dam (Gombe State)
The Dadin Kowa Dam is in Gombe State, Nigeria’s northeast. The dam, 35 km east of Gombe town, offers drinking water. The federal government completed the dam in 1984 to provide irrigation and energy for the Gongola sugar plantation. The reservoir, with a water capacity of 2.8 billion cubic metres and a surface area of 300 square kilometres, could be a source of fish. The reservoir displaced 26,000 people with little resettlement aid. The reservoir is suspected of breeding river-blinding black flies. CGC Nigeria, a Chinese corporation, built the N8.2billion water supply project during Governor Mohammed Danjuma Goje’s administration. In 2010, it provided roughly 30,000 cubic metres daily, which was piped to storage reservoirs in Gombe and settlements along the way. In August 2001, the federal government said it would spend $32 million to finish Dadin Kowa Dam. In March 2009, N7 billion was committed to finishing the dam’s hydroelectric component and N500 million to complete the canal, which would irrigate 6,600 hectares of agriculture. Governor Goje indicated in August 2009 that channels would cost less than N600 million. After the government prioritised completion in 2016, the ministry finished the dam in August 2021. As of September 2021, the Ministry of Power still needed to enable full use of the dam’s energy as part of the grid.