Vast human-made Lake Kariba is at near-record low, causing daily power cuts and devastating two African economies

All is not well with the waters of Lake Kariba, the world’s largest human-made lake. A punishing drought has drained the huge reservoir close to record lows, raising the prospect that the Kariba Dam, which powers the economies of Zambia and Zimbabwe, may have to shut down for the first time in its 65-year history.

Under the heat of the dry-season sun, the lake looks vast, serene. But, earlier this year, a severe effect of El Niño caused the worst mid-rainy season dry spell in southern Africa in a century.