Year
1982Duration
UnknownCost
UnknownLocation
NigeriaProject achievements
Build a dam to irrigate sugar plantations
The Kiri Dam is in Adamawa state in the north east of Nigeria. Built across the Gongola river, the 1.25km-long, 20m-high dam was mainly completed in 1982. The scheme created the reservoir Lake Kiri, which has a capacity of 615m cubic metres.
The structure is part of an irrigation system for the Savannah Sugar Company (SSC), a major sugar cane plantation and processing firm set up by the Nigerian government and the London-based Commonwealth Development Corporation.
Designed by the British firm Sir Alexander Gibb and Partners, the dam was built by the Nigerian Engineering and Construction Company (NECCO), a firm largely owned by the Nigerian government
The dam is part of an irrigation scheme that includes a series of canals, a pumping station and storage reservoirs.
SSC was sold to Nigerian multinational Dangote Industries in 2002. By 2009, the company owned 32,000 hectares of land in the region, of which 6,330 hectares were in use, employing around 5,000 people.
The firm produces about 50,000 tons of sugar every year for the home market - Nigeria consumes around 1.1m tons of sugar annually.
Dangote also produces around 1,000 hectares of rice and other crops using the irrigation scheme.
Did you know …
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Kiri Lake – and the rivers and tributaries that feed into it – is home to a large hippopotamus population.
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Although popular with tourists, locals complain that the animals cause problems – destroying crops and sometimes attacking fishing boats.
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Community leaders have called for a hippo cull, or the construction of barriers to seal the beasts into the lake’s rivers and tributaries.
Difference the project has made
The dam and irrigation scheme have helped provide jobs for the local economy. Dangote employs 700 permanent staff and around 5,000 part-time staff, with seasonal workers during the harvest season.
There have been social as well as economic benefits - the company has invested locally, putting cash into schools and healthcare facilities.
How the work was done
The Kiri Dam is an earthfill dam – also known as an embankment dam. The structure is built round an internal core of clay.
Engineers construct earthfill dams by building up layers of earth, one on top of each other. They use the most impervious – waterproof – materials to create the core. Clay was used for the core of the Kiri Dam.
Workers place more permeable materials on the upstream and downstream sides of the embankment. Permeable materials – such as sand or gravel – allow liquids to pass through them.
Earthfill dams often have a facing of crushed stone to prevent wind or rain erosion. A spillway – passage for water – protects the structure against flooding in rainy weather.
More than 20,000 people were moved from their homes to make way for the Kiri scheme.
People who made it happen
- Client: the government of Nigeria
- Designer: Sir Alexander Gibb and Partners
- Construction engineers: Nigerian Engineering and Construction Company (NECCO)
