The Oyan River Dam is in Abeokuta North local government area of

Ogun State Ogun State is a state in southwestern Nigeria. Created on 3 February 1976 from the former Western State. Ogun State borders Lagos State to the south, Oyo State and Osun State to the north, Ondo State to the east, and the Republic of Benin to the ...

in the West of

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

, about 20 km north west of the state capital

Abeokuta Abeokuta is the capital city of Ogun State in southwest Nigeria. It is situated on the east bank of the Ogun River, near a group of rocky outcrops in a wooded savanna; north of Lagos by railway, or by water. , Abeokuta and the surrounding are ...

. The dam crosses the Oyan River, a tributary of the

Ogun River The Ogun River is a waterway in Nigeria that discharges into the Lagos Lagoon. Course and usage The river rises in Sepeteri Oyo State near Shaki at coordinates and flows through Ogun State into Lagos State. The river is crossed by the Ikere ...

. It is used primarily to supply raw water to

Lagos Lagos (Nigerian English: ; ) is the largest city in Nigeria and the List of cities in Africa by population, second most populous city in Africa, with a population of 15.4 million as of 2015 within the city proper. Lagos was the national ca ...

and Abeokuta, but has potential for use in irrigation and power generation.

Structure

The dam was commissioned on 29 March 1983 by president

Shehu Shagari Shehu Usman Aliyu Shagari (25 February 1925 – 28 December 2018), titled Turakin Sokoto from 1962, was the first democratically elected President of Nigeria, after the transfer of power by military head of state General Olusegun Obasanjo in ...

, and is operated by the Ogun-Osun River Basin Development Authority. The lake is in the savannah region, with sparse trees and grasses and low fertility. It covers 4,000 hectares and has a catchment area of 9,000 km². The dam has a crest length of 1044 m, height 30.4 m and gross storage capacity of 270 million m³. It was designed to supply raw water to Lagos and Abeokuta, and to support the 3,000 hectare Lower Ogun Irrigation Project. Three turbines of 3 megawatts each were installed in 1983 but as of 2007 had not been used.

Impact

During construction, 22 villages were submerged, with the displaced people moved to three settlement camps. Some of the settlers fish the lake and farm vegetables along the fertile shoreline as the lake recedes in the dry season. A 2009 study of levels of urinary

schistosomiasis Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody s ...

in the Ibaro-Oyan and Abule Titun communities, which depend on the Oyan Dam for their livelihood, found high levels of infection due to use of untreated water. An earlier study in 1990–1993 had indicated that the risk of the disease, which is carried by snails, could be greatly reduced if the reservoir were continuously discharged during the hot dry season.

Operations

In May 2009, after heavy rainfall the dam operators were forced to release exceptional amounts of water from the dam for safety reasons, causing some flooding over an area of 2,800 hectares. In February 2010 the dam was failing to deliver sufficient raw water for the Abeokuta water works to meet demands. The water works was also struggling with equipment failure due to a power surge. Residents of Abeokuta were forced to rely on rivers and streams to meet their water needs. The Ogun State Water Corporation attributed the problem to the unreliable supply of electricity from the Power Holding Corporation of Nigeria.

Potential

In 2010 the federal government budgeted N43 million for construction of the gravity irrigation scheme at the dam and N11 million for dam operations. The dam was intended to support 3,000 hectares in the first phase, but the land had been lying fallow.

References

{{Dams in Nigeria Dams in Nigeria Ogun State Dams completed in 1983 Water supply and sanitation in Lagos 1983 establishments in Nigeria