Victoria Falls is thundering again after a deluge of rainfall increased Zambezi River flows this week, prompting a deluge of beautiful photographs – but also public concern about the stability of the Kariba Dam downriver.
Images of a surging waterfall posted to social media sites by photographers show the waterfall traditionally known as Mosi-oa-Tunya, or “the smoke that thunders”, living up to its name for the first time in years after an extended drought that had reduced the African landmark to a shallow stream.
The Zambezi River Authority, a corporation that oversees the maintenance of dams on the Zambezi River, reported last week that the Zambezi River flows recorded at Victoria Falls were 54% above the long-term average.
The surge in water is expected to continue, as upstream Zambezi River flows recorded in Chavuma, Zambia, were 523% above flows recorded in 2019, the Zambezi River Authority reported. These are the highest flows reported in the past 20 years, indicating that Victoria Falls will soon experience a further surge in flows as the water moves downstream.
The revival of one of Zambia and Zimbabwe’s major tourist drawcards comes only a few days after the two governments announced Victoria Falls would be closed indefinitely due to the coronavirus outbreak. On the Zimbabwean side, tourist bookings in the area had already fallen by 50% before the lockdown as the government’s earlier Covid-19 restriction that all incoming tourists present a ‘health certificate’ prompted many cancellations.
Energy and environmental experts have expressed concern about the structural integrity of the Kariba Dam, which lies downriver from Victoria Falls and will take on the surging flow in the coming weeks.
The Kariba Dam has been undergoing repairs since 2015, in the wake of concerns that its retaining wall could collapse. A 2014 report on the damn’s possible collapse by the Institute of Risk Management of South Africa warned that 181 billion cubic metres of water could be released if the dam wall failed. It would take eight hours for a wall of water to reach and destroy the Cahora Bassa dam in central Mozambique. It was estimated at the time that the lives of 3.5 million people would be at risk and some 30 million others would suffer severe economic impact.
Repair work, according to the World Bank, has included reshaping the plunge pool to limit erosion and renovating spillway infrastructure. According to The Herald, repairing the spillway is especially important because it allows water to be released from Lake Kariba if water levels are too high. Without repair, the sluice gates may jam and cause the dam to overflow, putting downstream communities at risk, The Herald reported.
According to the ZRA, repairs to the plunge pool and spillway are not expected to be complete until 2023 and 2025, respectively. The authority has not commented on whether the dam will be able to withstand the increased river flows. The Kariba Dam provides electricity for both Zambia and Zimbabwe, but its inflow in the past year was below average, the Zambezi River Authority reported. This lack of water has been one of the causes of load shedding and electricity shortages in both countries.
