Walter Nyamukondiwa — Water levels in Lake Kariba are rising at an average of 2cm daily, amid projections that the lake would have gathered at least 7 metres available for power generation in June, when peak inflows reach Kariba.
This would significantly increase power generation latitude for utilities Zesa and Zesco (Zambia) to ramp up power production.
The Zambezi River Authority (ZRA) has curtailed power generation to around 300MW using part of current inflows.
Yesterday, Kariba South Power Station generated 318MW of power, marginally lower than the 384MW produced at Hwange Thermal Power Station.
Of the other smaller thermal power stations including Harare and Bulawayo, only Munyati was on stream, generating 17MW of power.
This means total local power generation was 719MW, which falls short of average daily demand of around 2000MW, with part of the deficit offset by imports.
With Kariba producing the bulk of the electricity relatively cheaper, at a time when Hwange Units 7 and 8 are set to increase the station's feed to the national grid, higher water levels augur well for increased production towards energy sufficiency.
Projected water inflows would push reservoir storage to within 2022 peak levels at around 33,5 percent of usable water for power generation, still far below the 2021 levels of 53,36 percent.
It remains to be seen how flows from the Upper Zambezi Catchment would impact the lake levels as it contributes at least 70 percent of inflows.
As of yesterday, there were 5,3 billion cubic meters of water available for power generation from 4,62BCM on January 30.
This means that about 0,68BCM of water flowed into the lake in the past seven days.
Zambezi River Authority hydrologist Engineer Pherry Mwiinga said flows at gauging stations on the Upper Zambezi River were encouraging.
Higher inflows boost water levels which are key in turning the turbines for power generation at Kariba South and North hydropower stations.
"The Lake is still rising at a rate of 2cm per day which saw the reservoir storage rising to 5,3BCM," said Eng Mwiinga.
"The mainstream Zambezi River is doing very well. Flows at Chavuma and Victoria Falls are rising steadily. We expect that the conditions will continue improving."
Eng Mwiinga said levels were expected to continue rising with peak inflows expected between June and July.
In 2021, peak inflows were recorded between June 4 and 6 while in 2022 peak inflows were recorded in mid-June.
