A hugely respected French company – Razel-Bec – has been granted a $294 million contract to rehabilitate the Kariba dam in order to stop the dam’s wall from collapsing.
Zambia and Zimbabwe will give French engineering firm Razel-Bec the task of making safe the Kariba Dam, whose wall is swelling, raising the risk of cracks in the structure designed to hold back up to 180 billion cubic meters of water. A collapse of the dam could pose a risk to 3.5 million people in Zambia and Zimbabwe as well as Malawi and Mozambique further downstream, according to a 2015 report by global risk managers AON.
“It is a real risk that the dam could fall without that effort being put in place,” Dam Maintenance Engineer Farai Furasa told Reuters, referring to the planned renovation. “Some forces are pushing toward the dam wall and digging into it and the water could slip underneath the dam and cause it to collapse,” he added.
The project is funded by the European Union, World Bank, African Development Bank, the Swedish government and the Zimbabwe River Authority (ZRA). Rehabilitation is set to begin in May, with a period of three years allocated for the completion of the plunge pool and eight years to refurbish the floodgates. Refurbishment of the plunge pool, where water from the flood gates falls into, will stop the dam wall from breaking, a development that threatens the lives of about three million people who live downstream of the Zambezi River.
ZRA chief executive Munyaradzi Munodawafa, said the work would focus on rehabilitating the safety deficiencies of the plunge pool. “This will allow the dam to spill using all the six gates instead of the current three, placing undue stress on the already compromised dam structure.”
“This alone will ensure that the dam is operated in a safe manner that will allow for the maximum amount for power generation to be to be stored as well as guaranteeing the safety of the millions of people downstream,” he said.
About 300 000 tons of rock will be excavated from the plunge pool to increase the surface area. The plan of refurbishing the Kariba Dam wall and plunge pool was discussed and investigated already in 2009 when a Zimbabwe and Zambia council of ministers approved the concept and mobilisation of funds for the project.
The EU head of the delegation to Zambia, Alessandro Mariani, said the Kariba Dam rehabilitation project was part of the Zambia-EU partnership in the energy sector aimed at improving access to clean, reliable and affordable energy. This is a priority for a sustainable and reliable source of energy.
“The technical preparations for the rehabilitation of the plunge pool, which is part of the Kariba Dam Rehabilitation Project, began in 2013 and with the signing of the works contract, we have reached an important milestone having successfully completed the tendering process which saw strong competition amongst a selected number of highly capable companies, with the required skill-set, at the international level,” Mariani said.
“Reshaping the plunge pool will lead to an increase in efficiency and an improved capacity to dissipate the energy generated by the so called spilling events. The contractor, Razel-Bec, who will be supervised by a ZRA project management team, is due to be on site in the coming weeks and months,” he concluded.
The dam, which was commissioned in 1960, provides both Zambia and Zimbabwe with water for electricity generation. The structure has served the citizens of all of Southern-Africa well, and it has become something of a man made wonder. Many foreign visitors have visited the dam and flew over it during the past half-century.
