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Kariba, world’s largest man-made dam on the brink of collapse

Fear, uncertainty and panic. This is how the people of Zambia and Zimbabwe are struggling to adapt to reports of a possible collapse of the Kariba Dam.

The Kariba Dam lies on the Zambezi River, straddling the border between Zimbabwe and Zambia, and is the world’s largest manmade reservoir by capacity. It is aging, raising grave concerns such as the possibility of chemical reactions occurring, as well as seepages and cracks on its wall forming. The dam is also vulnerable to earthquakes and heavy flooding from upstream waters into the plunge pool.

 

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The Kariba Dam © Adam Ojdahl/Flickr

Kariba Dam: what could happen

The dam was built in 1955 by Italian company Impresit, subsequently absorbed by Salini Impregilo, responsible for building the Gibe III dam threatening thousands of indigenous Ethiopians and Kenyans. The Kariba Dam, opened in 1959, is 579 metres wide and 128 high and holds back over 189 billion tonnes of water. It lies 1,300 kilometres upstream from the Indian Ocean.

“The sluice water causes an eddy which has carved a plunge pool over decades. The continual water erosion is cutting through the plunge pool backwards towards the dam, where it is beginning to erode the dam itself,” says Zambezi River Authority (ZRA) spokesperson Munyaradzi Munodawafa. “People should not panic because the authority is doing everything possible to contain the situation,” he continues.

 

Furthermore, according to a World Commission on Dams report, Kariba lies in a tectonically active area, at the southern end of the African Rift Valley system, a longitudinal fault zone.

 

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Directing the water flow © Adam Ojdahl/Flickr

What would happen if the dam collapsed

Authorities have warned that if no repairs are carried out within three years the Kariba may collapse. If that were to happen, it would cut Zambia off from about half of its electricity, a disaster for a country and region that already suffers severe power deficits. The rupture may also halt the tourism industry around the river as well as in the Lower Zambezi game parks downstream.

 

Raising funds for repair

The governments of Zimbabwe and Zambia have raised around 295 million dollars from international investors, out of the 300 million dollars target set for repairing the cracks that were discovered during assessments of the dam. Repair works have been set to start in March 2016.

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