Bloomberg reports that Zambia has reduced hydropower production at the Kariba Dam because of rapidly declining water levels at the world’s biggest man-made reservoir that straddles the border with Zimbabwe, the energy minister said.
“We have noted the poor water situation for the Zambezi system necessitating reduction in generation at Kariba,” Matthew Nkhuwa said, without providing further details.
Water outflows through the turbines at Kariba, which shows how much power they’re producing, has been cut by 27 percent this month.
The dam has dropped to 43 percent of capacity from 85 percent in October, as inflows from the Zambezi River that feeds it dwindle.
Flows at Victoria Falls about 120 kilometers (75 miles) upstream are less than half of what they were a year ago, and near a record low for this time of the year, according to data from the Zambezi River Authority, which manages the dam.
Still, water supplies at other hydroelectric facilities in the country have been favorable, including at Kafue Gorge, the second-biggest power plant in Zambia, Nkhuwa said in reply to emailed questions. These will cover any shortages at Kariba, and the government doesn’t foresee power cuts as a result, he said.
The depletion of Kariba’s waters is “very troubling,” said Will Pearson, a director at U.S.-based advisory company Triskel.
“The levels at Kariba’s reservoir have fallen dramatically in recent months, and the situation will likely exacerbate,” he said by email.
“Unlike Zambia’s last power crisis only three years ago, the ability to tap regional markets will be limited by the power shortage hitting South Africa and the arrears Zesco owes for previous emergency imports from Mozambique and to domestic suppliers.”
Mines in Zambia, Africa’s second-biggest copper producer, account for more than half of electricity demand and any shortages could cut output of the metal.
If there are extensive shortages, this could hit the mining industry and add to the likelihood of cuts to copper production this year, Pearson said. Companies including First Quantum Minerals Ltd. and Glencore Plc operate mines in Zambia.
The Kariba hydropower station is Zambia’s biggest electricity source, with capacity of 1,080 megawatts out of state-owned electricity supplier Zesco Ltd.’s total of 2,337 megawatts. The southern African nation suffered a power crisis with rolling blackouts lasting as long as 12 hours when Kariba’s water levels showed a similar drop in 2015.