Rain forecast boost for Kariba power generation

THE projected normal-to-above normal rainfall in the 2024/25 farming season is expected to boost water levels on the Zambezi River and Kariba Dam and ultimately improve energy generation and tourism.

According to regional weather experts who attended the 29th Southern Africa Regional Climate Outlook Forum (Sarcof-29) this week, Zimbabwe and other Southern African countries are set to receive normal to above normal rainfall in the 2024/25 farming season.

This forecast has brought hope of improved agriculture production and better food security for the coming year.
Zimbabwe has been classified under “Zone 2” for increased chances of normal to below-normal rainfall from October to December and normal to above-normal rainfall from November to March just like Central DRC, northern Zambia, eastern Malawi, Tanzania and parts of Mozambique.

This comes as a relief as the region is emerging from one of the worst droughts following low rainfalls in the 2023/24 rainy season, which has seen water levels on the Zambezi reaching record low and power generation on Kariba Dam being capped.

In a statement on the hydrological outlook for the Kariba Catchment and the status of water levels at the Kariba Dam, Zambezi River Authority (ZRA) acting chief executive officer, Engineer Sithembinkosi Mhlanga, said water levels were substantially lower than average due to the severe drought that was experienced during the 2023/2024 rainfall season.

She said the water level on the river and Lake Kariba were significantly lower compared to last year. Africa’s fourth longest river, the Zambezi River originates from Mukangala area North West of Zambia and flows into Angola, back into Zambia, Namibia, Botswana, Zimbabwe and Mozambique. It has three gauging stations at Chavuma, Victoria Falls and Kariba.

Water levels are significantly low in Victoria Falls whose light showers are currently hardly felt. The Victoria Falls is a major tourist drawcard.

“From the last update, river flows at Chavuma gauging station — the first station where the Zambezi River re-enters Zambia from Angola — continued to be in recession.

“The Zambezi River flows at Victoria Falls are also currently receding as expected for this time of year but are substantially lower than average due to the severe drought that was experienced during the 2023/2024 rainfall season,” said Eng Mhlanga.

“Lake levels at Kariba Dam have been receding due to reduced upstream inflows. Notably, the lake level remains lower compared to the corresponding period last year. A decrease of 2.59m is evident when comparing today’s lake level to the lake level of the same date in 2023.”

ZRA gives four-week updates on river flows. Between August 5 and Tuesday, water levels had decreased from 146 cubic metres per second to 102m3/s at the Chavuma gauge, compared to 128m3/s on August 27 last year, it said.

In Victoria Falls, levels were at 397m3/s on August 5 and had dropped to 324m3/s on Tuesday. Last year, levels dropped from 616m3/s to 457m3/s during the same comparable period. At Lake Kariba, water was at 477.00m on 5 August and dropped to 476.75m on Tuesday.

Last year it had dropped from 479.62m to 479.34m during the same period. Eng Mhlanga said the Sarcof held in Harare was meant to provide a consensus outlook for the upcoming 2024/2025 rainfall season.

She said ZRA will be guided by the actual 2024/2025 downscaled rainfall forecast for the Kariba catchment given by meteorological departments of Zambia and Zimbabwe.

“The Zambezi River Authority will utilise the downscaled Kariba Catchment rainfall forecast to undertake detailed hydrological simulations using its state-of-the-art Kariba Hydrological Inflow Forecasting Software System (IFS) and allocate water for power generation operations at Kariba dam for the year 2025.

“As per usual equity considerations, the allocation will be shared equally between Zesco Limited and Zimbabwe Power Company (ZPC),” she said.

“The authority assures the public that it continues to maintain constant surveillance over the hydrological outlook and the Kariba Catchment’s performance and also ensures timeous dissemination of information.” — @ncubeleon.

ZRA is a bilateral organisation that is jointly and equally owned by the Governments of Zambia and Zimbabwe. It operates, maintains, monitors and regulates the water level in the Kariba Reservoir, as well as having a mandate to construct, operate and maintain any other dam infrastructure on the Zambezi River and to collect, accumulate and process hydrological and environmental data for improved performance of its functions and the socio-economic development of the contracting States.