Zimbabwe and Zambia will experience further curtailed electricity generation from their two hydropower stations at Lake Kariba following a reduction in water allocation to their two power utilities for the coming year by the Zambezi River Authority (ZRA).
ZRA announced Thursday that the Zimbabwe Power Company and Zambia’s ZESCO Limited would equally share 16 billion cubic meters (BCM), down from the revised 30 BCM in 2023, as water inflows into the lake remained low because of poor rains in recent years.
ZRA chief executive officer Munyaradzi Munodawafa said in a statement that the bi-national organization was allocating the reduced allocation because of anticipated poor inflows from the lake’s catchment area. The organization in early 2023 allocated 40 BCM to be shared equally between the two power utilities but later revised the figure down to 30 BCM for the year as the lake’s water levels became too low.
“The 2024 water allocation was informed by the 2023/2024 rainfall forecasts made by the Southern Africa Climate Outlook Forum-27 and the corresponding downscaled projections by the National Metrological Agencies of Zambia and Zimbabwe, which all showed a high probability of a normal to below normal 2023/2024 rainfall season for the Kariba Lower Catchment and normal to above normal rainfall season for the Kariba Upper Catchment,” Munodawafa said. “This general outlook is highly influenced by the increasing occurrence of El Nino weather conditions, which are expected to significantly impact negatively, the rainfall season in Southern Africa. The 2023/2024 rainfall profile outlook implies a high likelihood of below-normal Zambezi River inflows into Lake Kariba.”
ZRA is mandated to contribute to the economic, industrial, and social development of Zimbabwe and by obtaining the greatest possible benefits from the natural advantages offered by the waters of the Zambezi River (between Zambia and Zimbabwe) through the most economical and effective means of providing water for generation of electricity and for other purposes which the two states may decide upon.
Munodawafa said the latest hydrological simulations considered the high likelihood of a below-average rainfall season which, in turn, would likely result in below-average inflows into Lake Kariba, thereby negatively impacting the volume of water available for power generation during the year.
“Accordingly, power utilities have been advised to consider alternative sources of power to complement generation at Kariba in order to fill any power generation deficit that could arise due to the lower water allocation at Kariba for the year 2024,” he said.
Munodawafa said lake levels at Kariba continued to recede during this time of the year, mainly due to lower inflows than outflows, with isolated fluctuations being observed recently due to sporadic rainfall activity on the lake.
“The 2023/24 rainfall season performance of the lower Kariba Catchment thus far has been poor, resulting in below-normal inflows into Lake Kariba,” he said.
The recorded lake level on Dec. 27 was 477.12 m with 7.25 BCM or 11.19 percent live storage, he said.
“With the two power generation utilities generating power within the confines of their respective water utilization plans for the year 2023, the lake is projected to close the year 2023 at 477.23 m with 7.78 BCM of live storage which translates to 12 percent live storage. It is recommended that the highest possible live storage be maintained going into 2024 as a buffer against the anticipated below-normal inflows,” he said.
He implored the two power utilities to adhere to their approved allocations to ensure sustainable management of the Kariba reservoir.
In Zimbabwe, many companies are reeling from the effects of curtailed power supplies.