The power station straddles the border with Zimbabwe and supply both countries with electricity.
According to Reuters, the two countries have agreed to reduce electricity production on each side of the border, from about 1,000 MW, to 500 MW.
Water outflows through the turbines at Kariba has been cut by 27 percent this month.
According to a technical bulletin issued jointly by Zambia, Zimbabwe and Mozambique, the water level in the Kariba dam has dropped to 43 percent of capacity from 85 percent in October.
The Kariba hydropower station is Zambia’s biggest electricity source, with capacity of 1,830 megawatts out of state-owned electricity supplier Zesco Ltd.’s total of 2,337 megawatts.
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, LusakaTimes newsportal reported.
Zambia suffered a power crisis with rolling blackouts lasting as long as 12 hours when Kariba’s water levels showed a similar drop in 2015.
Kariba Dam rehabilitation project will cost $294.2 million. Co-operating partners will provide the funds, officials said.