Kariba dam at risk of collapse, report warns

Concerns around a “catastrophic” failure of the Kariba dam, between Zambia and Zimbabwe, have again been spotlighted, as Zambia’s Energy and Water Development Minister last week announced the possible shutdown of its hydroelectric plants, with the dam’s water levels dropping to below 14%.

Zambian Geological Survey Department director Chipilaika Mukofu said experts were still assessing the possible effect that the 4.6-magnitude earthquake on January 12 may have had on the dam.

A report released in September by Aon South Africa and the Institute of Risk Management cautioned that the impact of severe drought brought about by El Nino and the overuse of water for power generation, coupled with further project delays in critically needed rehabilitation work, could accelerate failure of the dam.

The ‘Impact of the failure of the Kariba dam’ report held that the dam was in a “dangerous state”, with torrents from the spillway having eroded the bedrock and undercutting the dam’s foundations.

“Engineers have been warning for some years now that, without urgent repairs, the whole dam will collapse, knocking out Mozambique’s Cahora Bassa dam and 40% of Southern Africa’s hydroelectric capacity. Along with the devastation of wildlife in the valley, the lives of 3.5-million people are at risk,” Aon warned.

The group further cautioned that a collapse of the dam would result in significant loss of life, damage to property and an economic fallout that would devastate the region’s economies.

“In December 2014, the critical period was defined as ‘the next three years’, while the rehabilitation project is only due for completion in 2025.