Kariba Dam Wall In Risk Of Collapse,$250m Required For Repairs

AT LEAST 3,5 million people in Zimbabwe, Malawi, Mozambique and Zambia are in danger amid disclosures that the Kariba Dam wall has developed “serious structural weaknesses” which need to be rectified within the next three years. 

While the Zambian government acknowledged the gravity of the situation, their Zimbabwean counterparts were attempting to downplay it. 

Zambia’s Finance Ministry permanent secretary Felix Nkulukusa told NewsDay yesterday that the dam wall risked being washed away if nothing was done in the next three years. Nkulukusa, who is also chairperson of an inter-governmental committee responsible for mobilising funds to repair the dam wall, said Zambia and Zimbabwe must raise $250 million to avert a major humanitarian and economic crisis.

Zambia and Zimbabwe must raise  $250 million to avert a major humanitarian and economic crisis. 

But Zimbabwe’s Environment, Water and Climate minister Saviour Kasukuwere on Wednesday downplayed the impending disaster saying he was not aware of it as the dam wall was already going through some repairs.

“What we know is that the dam wall is undergoing repairs, but it does not mean it is collapsing.”

However, Nkulukusa said:

“Engineers have told us that the dam wall could be washed away in the next three years. The plunge pool was originally 10m deep, but is now 81m deep due to erosion from falling water. The erosion is now going towards the dam wall and the whole dam wall will be eaten away if the situation is not arrested now.”

He said $80 million was required to repair the plunge pool alone. According to the Zambezi River Authority (ZRA), routine maintenance work was done periodically on the dam wall and its appurtenances. “Several stability works have been carried out on the south bank comprising drilling of drainage audits, surface sealing of the slope, ground re-profiling,” ZRA said on its website.

KARIBA DAM GRAPHICS ZRA however, said Kariba Dam suffered from alkali-aggregate reaction, which induces swelling within the concrete mass, but extensometers were installed to monitor the concrete swelling. ZRA is jointly owned by Zimbabwe and Zambia to operate, monitor and maintain the Kariba Dam and reservoir, all telemetering stations relating to the dam and any other installations owned by the authority. 

Nkulukusa said another problem was caused by the spillway that was no longer opening and closing automatically to maintain the required water levels. He said this problem was being caused by the expansion of the concrete on the walls and rusting of the steel bars. Repairing of the spillway, Nkulukusa said, would need $120 million, while $50 million was required for other unexpected costs. 

“The spillway is now bending and is not opening automatically. The water we are blocking can exert pressure on the dam wall and it may fall. When this happens, over 3,5 million people downstream in Mozambique, Malawi Zambia and Zimbabwe will be affected,” he said. 

Nkulukusa said Zimbabwe and Zambia only availed $2,5 million through the ZRA for some remedial maintenance and not the major repairs. “We have approached the World Bank, the African Development Bank and the European Union. They have pledged to fund the repairs. We met in February and they promised to go and brief their respective head offices, we are still waiting for the response,”