Kariba Gets More Water for 2025, but Zambia's Power Supply Still Hangs on One Lake
The Zambezi River Authority, which manages Lake Kariba on behalf of Zambia and Zimbabwe, has allocated 13.5 billion cubic metres of water to ZESCO, Zambia's state utility, for power generation at the Kariba North Bank station in 2025. That compares with 8 billion cubic metres in 2024, according to reports in the Zambian press in early March. The higher allocation should allow more generation, but it follows one of the worst years for hydropower in the region's recent history.
Through 2024, a severe drought across southern Africa, linked in part to the El Niño event, cut inflows into Lake Kariba to very low levels. Lake Kariba is one of the largest man-made reservoirs in the world by volume, formed by the Kariba Dam on the Zambezi. The 2024 allocation of 8 billion cubic metres was well below normal levels, and ZESCO had to manage generation within that limit for the full year. Copper mining, the country's main export industry, depends on reliable electricity, and mines with long-term supply contracts faced curtailment or turned to imports and on-site generation.
The increase to 13.5 billion cubic metres reflects better rainfall in the 2024 to 2025 wet season. The Southern African Power Pool allows Zambia and Zimbabwe to import electricity from neighbours, including Mozambique, South Africa and Namibia, subject to transmission capacity and the availability of surplus power. Mozambique's Cahora Bassa hydropower station, downstream on the Zambezi, is also affected by the river's flow, which means regional drought can reduce output across several hydro plants at once.
Zambia's government has announced plans to diversify its power supply away from heavy reliance on hydropower. Zimbabwe has also pursued additional coal capacity at Hwange, where new units have been commissioned in recent years, and has opened the door to private solar projects. For international energy markets, the Kariba drought is a regional story with two wider implications. The main variable for the rest of 2025 is rainfall in the 2025 to 2026 wet season, which begins in November.