The Zambia government has appealed urgently to the World Bank, the European Union (EU), the African Development Bank (AfDB) and other international financiers to provide funding for rehabilitating the Kariba dam wall, following expert confirmation that it has developed serious structural defects and warnings that it may collapse, with catastrophic results, within the next three years.
A collapse of the dam wall would put the lives and livelihoods of more than 3.5 million people in Zimbabwe, Zambia and Mozambique at risk. The Zambezi River Authority (ZRA), has confirmed that the dam wall needs urgent rehabilitation. However, it says there is no need to panic as engineers still have the situation under control.
The authority has identified three temporary maintenance programmes to be undertaken while a lasting solution is sought. Major structural defects include the spillway, which is no longer bending and does not open automatically, owing to the expansion of the concrete on the walls and heavy accumulations of rust on the steel bars.
The plunge pool below the dam wall has reportedly deepened from 10 m when the dam was built in 1959 to nearly 90 m at several points along the dam wall. The plunge pool erosion is reported to be gradually moving towards the 128-m-high wall, leading to fears that it may soon be undermined, destabilised and eventually collapse as the stabilising rock layer continues to erode.
By: Oscar Nkala