The Zambezi River Authority (ZRA) has begun work to rehabilitate the Kariba Dam, located on the border between Zambia and Zimbabwe. Financed by several financial institutions, the operation will cost $294 million.
The Kariba hydroelectric dam is now being rehabilitated. Major works have just been launched by the Zambezi River Authority (ZRA), which manages the dam. Ongoing work will reshape the diving basin downstream of the dam wall and rebuild the spillway.
This last component of the Kariba dam consists of six gates, located in the upper part of the dam’s concrete wall. It is from these valves that water is discharged into the diving basin to manage the water levels in the reservoir. “The rehabilitation of the spillway will ensure continuous monitoring and safe discharge of water from the reservoir when necessary. This will make the Kariba dam fully operational, and allow it to make its contribution to securing energy supplies,” explains Munyaradzi Munodawafa, an engineer from the ZRA.
An urgent rehabilitation!
Work on the dam site was now accelerated after a worrying delay observed by the ZRA, which coordinates the operations. The organisation, jointly managed by Zambia and Zimbabwe, had to build an access road for the transport of a 130-ton crane to be used for the rehabilitation of the dam. The Kariba Dam Rehabilitation Project comes 5 years after experts observed the first cracks on this large dam.
“The level of Lake Kariba is currently 5 m above the minimum operating level, whereas it should be 8 m above the minimum operating level at this time of year,” explains the ZRA. This situation logically leads to a decrease in electricity production. The production capacity of the hydroelectric power plant (1626 MW) attached to this dam has already fallen by about 600 MW. The situation could worsen in the coming years if the water retention is not restored. The rehabilitation of the Kariba hydroelectric dam will require an investment of $294 million. Financing is provided by the ZRA through equity and loans from the World Bank, the African Development Bank (AfDB), and the European Union.
Designed by the French company Coyne et Bellier, the Kariba dam was built by Impresit of Italy and commissioned in 1959. It is a double-curved concrete arch dam in the gorge of the Zambezi River Basin. The structure is 128 m high and 579 m long. The water reservoir forms Lake Kariba, which covers 5,580 km2 and contains 180 billion m3 of water.
However, the ZRA fears the collapse of this dilapidated structure, which could lead to a disaster, such as the collapse of the dam on Wednesday, May 9, 2018, at around 9 p.m., in Solai, 200 km northwest of Nairobi. Forty people had died…
Jean Marie Takouleu