Chronicle Editor
Oliver Kazunga, Senior Business Reporter
THE Zambezi River Authority (ZRA) has maintained the volume of water allocated to Kariba Hydro Power Station for electricity generation at 45 billion cubic metres this year.
The allocation is subject to a downward review if the region receives below normal rainfall.
Last year during the same period, ZRA allocated 30 billion cubic metres before the allocation was revised twice to reach 45 billion cubic metres in November following significant flows at Zambezi River and the resultant Lake Kariba inflows
Zimbabwe and Zambia through their power utilities – the Zimbabwe Power Company (ZPC) and Zambia Electricity Supply Corporation (Zesco) – share the allocation equally for electricity generation.
ZRA said the latest allocation was informed by the predictions of normal to above-normal rainfall that has been provided by regional weather and climate experts.
“The authority allocated 45BCM to be shared equally between Zesco Limited and Zimbabwe Power Company for their respective power generation operations at Kariba during 2022.
“The allocation was, among other factors, informed by the predictions of normal to above normal rainfall provided by the regional weather and climate experts mentioned above, but will be subject to a downward review where the rainfall season turns out to be a drought period to conserve the stored usable water and support power generation operations into 2023,” it said.
Owing to the delayed onset of the 2021/2022 rainfall season, ZRA has cautioned the two power utilities not to generate at higher levels (currently 550Mw for each Kariba power station) than that associated with the water allocation made for this year.
ZRA was now preparing to undertake the hydrological review for the first quarter of 2022 that will further inform the water allocation for power generation operations at Kariba.
“As per the historical hydrological trend, but compounded by the delayed onset of the 2021/2022 rainfall season, the Lake levels receded during the last quarter of 2021 into the first week of January 2022.
“However, owing to the recent steady increase in rainfall activity and associated increase in Zambezi River flows as well as the resultant Lake Kariba inflow, the Lake level rose from 478,23 metres recorded on 7th January 2022 to 478,47m recorded on 17th January 2022, positioning the lake 2,97 metres above the Minimum Operating Level (MOL) of 475, 50m,” it said.
This translates into 13,43 billion cubic metres or 21 percent of stored usable water or live storage.
On the same date last year, the lake level was slightly higher at 478,63m with 14,17 billion cubic metres or 21,87 percent of usable storage, with the lake level being 3m above the MOL.
During the last quarter of 2021, ZRA requested ZPC and Zesco to reduce their power generation levels for six hours on a few selected dates to facilitate coffer dam construction works under the plunge pool reshaping sub-project of the Kariba Dam Rehabilitation Project.
In doing so, ZRA said the two utilities were expected to implement measures that would mitigate the resulting reduction in power generation levels at Kariba.
“The specific works under the pool reshaping sub-project that called for this need have since advanced and are due to be completed by 25th January 2022, thereby ending the authority’s request to the two power generation utilities.
“Going forward, the remaining works of the Kariba Dam Rehabilitation Project will not result in the two utilities seeing reduced generation levels at their respective Kariba power stations,” it said.
The Kariba Dam Rehabilitation Project is scheduled to be completed by 2024 and is aimed at assuring the long-term safety and reliability of Kariba dam.
—@KazungaOliver
Online Reporter