El Nino Weather Conditions negatively impact water inflows into Kariba Dam

THE prevailing El Nino weather conditions continue to negatively affect water inflows into the Zambezi and Kariba Dam, the Zambezi River Authority (ZRA) has said.

In a statement, ZRA chief executive Mr Munyaradzi Munodawafa said inflows have been unpredictable, looking at current statistics compared to the same period last year.

As such, Mr Munodawafa said in line with its mandate, ZRA continues to closely monitor the hydrological outlook of the Kariba Catchment.

The hydrological review will among other factors take into consideration the actual performance of the 2023/2024 rainfall season and the resulting inflows into the lake over the first quarter of the year 2024.

Water allocation for electricity production is affected as ZRA has maintained the 16BCM for the two contracting countries.

“The results of the hydrological simulations could result in an increment, reduction, or the keeping of the prevailing 2024 water allocation as is. The Authority will continue monitoring the hydro meteorological performance of the Kariba Catchment as evolving under the prevailing El Niño climate conditions and keep the public informed of any new positive or negative developments.

“Given that the Kariba inflows are so far below average, with a possibility of registering as one of the lowest on record, the Power Utilities have been advised to maintain strict adherence to their respective water allocation thresholds to sustain generation to the end of the year,” said Eng Munodawafa.

He said as announced in December 2023, based on the rainfall outlook from an ensemble of climate centres of excellence available in Quarter 4 of 2023, ZRA allocated a total of 16 Billion Cubic Meters (BCM) of water for power generation operations at Kariba for the year 2024, to be shared equally between ZESCO Limited and Zimbabwe Power Company/Kariba Hydro Power Company.

As a way forward, he said, given that the outcome of the rainfall forecast is generally below normal, ZRA has maintained the 16 BCM water allocation for the year 2024 providing for combined annual average power production of 428MW, shared equally.

“The water allocation of 8 BCM per power utility, translates into an average power production of 214MW per Utility to the end of March 2024 when the 1st Quarter 2024 hydrological review falls due as per standing operational framework for Kariba dam reservoir operations,” he said.

Eng Munodawafa said water flow on the Zambezi at Chavuma gauging station, rose from a flow of 350m3/s recorded on January 1, 2024,to a peak of 530m3/s on 23rd January 2024, after which the flows receded down to 357m3/s on 6th March, compared to the flow of 992m3 /s recorded on 6th March 2023.

Zambezi River flow at the Victoria Falls rose from 492 m3 /s recorded on 1st January 2024 to 800 m3/s recorded on 4 March 2024 after which the flows have been receding, subsequently recording a flow of 794m3 /s on 6th March 2024.

Last year at the same time, 2,569m3/s were recorded.

Eng Munodawafa said Kariba Lake levels rose from 477.24m on 1 January 2024 with 7.80 Billion Cubic Meters (BCM) of stored usable water, representing a live storage of 12 percent, to 477.87m with 10.68 BCM of stored usable water or 16.49 percent live storage recorded on 29th January 2024.

During the first week of the month of February 2024, the lake level registered a sluggish increase.

He said water began to steadily decrease due to low inflow and reduced rainfall activity associated with the below-average rainfall received in the catchment area.

On Wednesday 6 March lake level was 477.66m with 9.72 Billion Cubic Meters (BCM) of stored usable water or 15.00 percent live storage.

On the same date last year, the recorded lake level was slightly higher at 477.68m with 9.81 BCM of stored usable water or 15.15 percent live storage.

“The Kariba Catchment has recorded below-normal rainfall owing to the persisting effects of El Niño weather conditions globally and over the Southern African region, in particular.

“According to the predictions published by the 28th meeting of the Southern Africa Regional Climate Outlook Forum (SARCOF-28) at the end of January 2024, indications were that the larger part of the Kariba Catchment was likely to receive Normal-To-Below-Normal Rainfall during the peak of the 2023/24 rainy season until April 2024,” said Eng Munodawafa.

The Zambezi River Authority is a Bi-National organization mandated to contribute to the economic, industrial, and social development of Zambia and Zimbabwe by obtaining the greatest possible benefits from the natural advantages offered by the waters of the Zambezi River.