Kariba deep basin dewatering begins
DEWATERING of the deep basin of the Kariba Dam has begun, with the Zambezi River Authority (ZRA) guaranteeing that the exercise will not lead to “drastic” changes in the river level and power generation constraints in the hydroelectric power stations supplied by the dam.
Last month, the ZRA announced during pre-drying awareness drills that the drill would not cause drastic changes in water levels in dams and rivers.
The Kariba Dam, the largest man-made lake in the world by volume, is currently Zimbabwe’s largest source of electricity.
The southern African country completed the power plant’s output expansion in 2018, increasing output from 750 MW to 1,050 megawatts.
Zimbabwe is currently facing an acute shortage with demand peaking at 2,200 MW, particularly in winter, against reliable generation of 1,600 MW.
The country is facing growing demand for electricity from economic expansion and from new housing and industrial users.
The Kariba Dam deep basin dewatering exercise started last Thursday and the ZRA said the first 10 meter drawdown of the water level in the deep basin is expected to be achieved by Friday this week.
The project includes the redesign of the Kariba Dam’s deep basin to address safety deficiencies as well as the refurbishment of six flood gates to improve operational control of reservoir discharges.
The rehabilitation of the artificial dam shared by Zimbabwe and Zambia aims to ensure the long-term reliability of power generation by the two nations and the entire Southern African region.
“We would like to assure our stakeholders that the water pumping operations on the second day of this exercise are progressing well and that the controlled volumes of water discharged from the deep basin will not cause drastic changes in river levels. , as previously communicated during the pre-drying sensitization exercises that were conducted in Zambia and Zimbabwe in June 2022.
“Furthermore, the Authority wishes to assure the general public that as the dewatering exercise continues, the operations of the Kariba North Bank and Kariba South Bank Power Plants will in no way be affected by the ongoing works. course,” the ZRA said in a statement.
The authority said the dewatering process started after the successful completion of the construction of the temporary cofferdam.
“The first 10 meter water level drawdown in the Plunge Pool is expected to be achieved by July 15, 2022. This is a very significant milestone in terms of the Plunge Pool remodeling works component. of the Kariba Dam Rehabilitation Program, which is funded by the European Union through the 11th European Development Fund.
“On Thursday, July 7, 2022, the last cofferdams of the deep basin cofferdam were successfully installed, leading to the start of the first phase of dewatering,” he said.
He said this important drill, which is a prerequisite for the deep basin remodeling work, is vital and will enable the contractor to carry out the excavation work efficiently in dry conditions.
The dewatering of the deep basin is part of the Kariba Dam rehabilitation program funded by the European Union through the 11th European Development Fund.
The $300 million project is jointly funded by the World Bank, the European Union, the African Development Bank, the Swedish government and the Zambezi River Authority, a binational organization that operates the dam on behalf of the governments of the Zambia and Zimbabwe.
The dam, built on the Zambezi River that separates Zimbabwe and Zambia between 1956 and 1959, was commissioned in 1960.