HARARE: The prolonged dry spell in the lower catchment of the Kariba Dam, which straddles Zimbabwe and Zambia, has resulted in a decreased inflow of water into the world’s largest man-made lake, but inflows are expected to increase during the second quarter of 2022.
In the second update for the year on the hydrological situation at Lake Kariba released Saturday, the chief executive officer of the Zambezi River Authority (ZRA) Munyaradzi Munodawafa said the lake level increased from 478.35 m recorded on Jan. 1, 2022, before receding to 478.52 m recorded on March 18.
ZRA is a bi-national organization mandated to contribute to the economic, industrial, and social development of Zimbabwe and Zambia by obtaining the greatest possible benefits from the natural advantages the two countries decide on. The two countries run power stations on the banks of the dam wall, which were in recent years expanded by Chinese engineers to generate more power.
“The increase in the lake level at the beginning of January 2022 was mainly due to sustained rainfall activity in the Kariba Lower Catchment, but the lake level then receded due to a reduction in rainfall activity,” said Munodawafa. “During that period, the Kariba Upper Catchment that contributes the larger portion of inflows into Lake Kariba experienced a delayed onset of rainfall activity. The lake level of 478.52 m recorded on March 14, 2022, meant that the lake was at 3.02 meters above the Minimum Operating Level (MOL) of 475.50 m.”
This translated into 13.66 billion cubic meters (BCM) of stored usable water or 21.07 percent live storage available for power generation, he said.
On the same date in 2021, the lake level was higher at 481.44 m with 27.62 BCM of stored usable water or 42.62 percent of live storage, with the lake level being 5.94 m above the MOL.
Munodawafa said despite the delayed onset of rainfall activities in the Kariba Upper Catchment, the preliminary hydrological simulations undertaken by ZRA indicated that owing to the upper catchment rainfall activity that continued to be recorded, the lake level would start increasing during the second quarter of the year.
“The simulations also indicated that the lake is likely to reach a peak of 480.30 m by June 18, 2022, which will put the lake at 4.8 m above the MOL with 22.06 BCM of stored usable water or 34 percent live storage available for power generation),” he said.
He said ZRA had maintained the 45 BCM of water allocated to ZESCO Limited and Zimbabwe Power Company for their respective power generation operations at Kariba for 2022. ZESCO Limited is the state-owned power company of Zambia.
“In line with its mandate, the authority will carry out a detailed quarterly review of the hydrological outlook at Kariba at the beginning of April 2022,” he said.