Writes Elvis Dumba
After over 60 years of serving the people of Zimbabwe and Zambia, the routine monitoring of the Kariba Dam identified the need for rehabilitation works to ensure its continued contribution to energy security and economic prosperity in both countries and the region.
The Kariba Dam Rehabilitation Program comprises the reshaping of the plunge pool to limit the likelihood of scouring and preferential erosion, particularly along the weak fault zone towards the dam foundations.
On the other hand, the refurbishment of the spillway upstream control facility should improve international dam safety standards and prevent potential failure of the facility.
The spillway is being refurbished to manage the reservoir water levels. It comprises six sluice gates in the upper part of the concrete wall, of which the cement has swelled due to Alkali Aggregate Reaction (AAR), a condition under which the aggregates in the concrete react to alkaline in the cement that can affect the smooth opening and closing of the gates that could possibly cause the spillway gates to jam in either open or closed position.
Since 1958, the Zambezi River Authority has monitored the performance of the dam infrastructure in accordance with the Standard Operating Procedure. This routine monitoring and management of the spillway system has resulted in the recommendation that the six spillway gates be refurbished to ensure their continued full operability in the long term.
The objective of the rehabilitation is to improve the safety and reliability of the Kariba Dam at a cost of USD$294 million being funded by the World Bank, the African Development Bank, the Governments of Sweden, Zimbabwe, and Zambia through Zambezi River Authority through a combination of grants and loans.
The plunge pool reshaping is wholly funded by the European Union through a €72 million grant to the Government of the Republic of Zambia.
The rehabilitation program is expected to be completed by the year 2025.
Recently, the Minister of State for Provincial Affairs and Devolution for Mashonaland West Province, Hon Marian Chombo accompanied the Special Advisor to the President on Monitoring and Implementation of Government Projects, Hon Jorum Gumbo to check progress on the project.
Hon Chombo highlighted the need for preventive measures in the face of climate change.
“The rehabilitation of the plunge pool has led to an increase in efficiency and an improved capacity to dissipate the energy generated by the so-called spilling events. Adding on, the project will help the Zimbabwe and Zambian Governments to develop such plans to allocate water resources and guide public investment decisions on new water development projects.
“It will also establish sustainable arrangements for the operation and maintenance of other large dams. The effects of climate change are proof of the importance of taking preventative measures to ensure dam safety.
“I am encouraged to see the Government’s high priority and commitment to these endeavours which is evident from the National Development Strategy 1(NDS1) with the construction and rehabilitation of dams as one of the key enablers to the achievement of targets set under Vision 2030. As emphasized by the President of the Republic of Zimbabwe, Dr. E.D. Mnangagwa, given that these are a key enabler to our national economic plan as envisaged under Vision 2030, we are determined to leapfrog the quality of our infrastructure across the country,” she said.
This rehabilitation work will empower the community to expand energy production and all the other water-related projects. Besides being a source of energy, Kariba Dam also offers a huge market for the provincial tourism market.