The Kariba Dam Rehabilitation Project (KDRP), meant to ensure the dam’s longevity, long-term efficient operation into the future, and its continued contribution to energy security for the Southern African neighbouring countries –Zimbabwe and Zambia is progressing well.
The rehabilitation project comprises the reshaping of the plunge pool and the refurbishing of the spillway gates. The works commenced in2017 with the plunge pool reshaping and according to the current project programme, the KDRP will be completed in 2025.
The natural river bed downstream of the dam has eroded overtime as a result of heavy spillage of flood waters, particularly in the dam’s early years, to form a deep plunge pool.
The $294 million project is being funded by the European Union, World Bank, African Development Bank, the government of Sweden and the Zambezi River Authority on behalf of the governments of Zambia and Zimbabwe, through a combination of grants and loans.
In a statement last week, the Zambezi River Authority announced that the construction of a temporary cofferdam has been successfully completed to allow works to reshape the plunge pool to commence.
“The Zambezi River Authority (Authority) wishes to inform residents of the communities located downstream of the Kariba Dam and the general public… that the Authority working together with the Contractor, Razel Bec, commenced the Kariba Dam Plunge Pool dewatering process on 7 July 2022.
“The first 10 metres draw-down of the water level in the plunge pool is expected to be achieved by 15 July 2022. This is a very significant milestone in respect of the Plunge Pool Reshaping works component of the KDRP,” read part of the statement.
“…the last Stop logs of the Plunge Pool Cofferdam were successfully installed, hence leading to the commencement of the first phase of dewatering. This important exercise, which is a prerequisite to the plunge pool reshaping works is vital and will enable the Contractor to effectively execute the excavation works in dry conditions.
“We wish to assure our stakeholders that the water pumping operations on day two of this exercise are progressing well and that the controlled volumes of water being discharged from the plunge pool will not lead to any drastic changes in river levels, as previously communicated during the de-watering sensitization exercises that were conducted in Zambia and Zimbabwe in June 2022,” further read the statement.
Further, the Authority said the de-watering exercise would not affect operations at the Kariba North Bank and Kariba South Bank Power stations.
The Kariba Dam is the largest man-made reservoir in the world. At a height of 128m and with a crest length of 617m, the dam has the capacity of holding 181 billion cubic metres of water. Designed as a double curvature concrete arch dam, the Kariba Dam was constructed across the Zambezi River between 1956 and 1959.
Commissioned in 1960, the Dam has been central to regional energy security and economic development ever since. The Kariba Reservoir supplies water to two underground hydropower stations with a total capacity of 1830MW generating more than 10,035GWh of electricity annually.
The North Bank Power Station is operated by ZESCO in Zambia and has an installed capacity of 1,080 MW. The South Bank Power Station is operated by ZPC in Zimbabwe and currently has an installed capacity of 750 MW,with projects underway to increase this to 1,050 MW.