Hope for power generation as Kariba rises

by | Feb 23, 2023 | Business, Local News | 0 comments

Hope for power generation as Kariba keeps rising

Hosia Mviringi

The incessant rains that have continued to pound the SADC region and some parts of Central Africa for the better part of this summer season has given a new lease of life to fading hopes on the prospects of power generation at Lake Kariba.

The Zambezi River Authority (ZRA), in their first update on the state of water inflows into Kariba for the year 2023 provided the latest message of hope to desperate power users in the two nations whose households and industries continue to face debilitating episodes of load shedding as a result of inadequate generating capacity.

The ZRA noted the marked increase in water inflows and expressed hope that if the current flow rate is maintained, power generation could be increased at both generation stations North and South of the Zambezi.

“It is worth noting that the lake level at Kariba, which has experienced a recession in the last quarter of 2022, has been rising steadily following the onset of the rains on and around the lake and Zambezi River Upper Catchment.”

“The year 2023 commenced with a low laje level of 475.61m, or 0.83 per cent of live storage available for power generation on the first of January, 2023. This was an increase from the lowest recorded level of 475.60m (10cm above Minimum Operating Level) recorded on December 30, 2022,” said ZRA in the update.

In the update, ZRA revealed that water levels had risen to 9.32 per cent of stored usable water for power generation, giving hope to power consumers who have endures rolling blackouts due to power load shedding

“From this lower lake level, the level now increased to 476.85m recorded today 16 February, 2022, which translates to 6 Billion Cubic Meters (BCM) or 9.32 per cent of stored usable water meant for power generation by the two utilities, Zimbabwe Power Company (ZPC) at Kariba South, and ZESCO Limited at Kariba North. This level translates to a rise of 1.24m from the level recorded on January 01, 2023,” said the statement.

The current recorded water level places the Dam at 1.35m above the Minimum Operating Level (MOL) of 475.50m, almost guaranteeing the safety of operating the two power stations, albeit at limited capacity.

According to the Africa Rainfall Climatology (ARC) Rainfall Estimator (RFE) of the Climate Prediction Centre (CPC) of the United States of America, the Kariba Catchment can be said to have received normal rainfall over the most parts of the Upper Catchment and normal to below normal rainfall over the larger part of the Lower Catchment during the last 90 days of the 2022/2023 rainfall season which stretches between November 2022 to February 2023.

This predictive outcome dovetails with the seasonal rainfall outlook predictions of both the CPC and SADC Climate Services Centre’s 26th Southern Africa Regional Outlook Forum (SARCOF-26) and the downscaled forecasts of the two Meteorological Departments of Zambia and Zimbabwe, of normal to above normal rainfall over Southern Africa in general, and the Kariba Catchment in particular.

The prevailing rainfall situation has therefore contributed to the current average inflows into Kariba Dam during the period under review, which, aided by a controlled generation outdoors, has been responsible for the steadily rising water levels at the iconic Kariba Dam.

The Zambezi River Flow rate, as recorded at Victoria Falls on 16 February 2023, was 1,412m³/s, rising from a low of 502m³/s recorded at the beginning of the year on January 01, 2023. At this flow rate, the season promises to be much better than the previous one which recorded a paltry flow rate of 989m³/s on the same date in 2022. The flow rate is expected to keep the upward trajectory until it reaches its peak in the second quarter of the year 2023, that is between April-June.

Despite the inflows from the Barotse Plains in the Western Province of Zambia most likely begin to feed into Kariba in the Second quarter of the year, not much changes inasmuch as water allocation to the power plants is concerned, at least in the short to medium term. This means that both power utilities will be expected to continue observing the current water usage parameters to avoid over usage of available capacity .

Power generation was reviewed upwards recently to 350MW on both sides, up from 250MW in December 2022 in response to positive inflows. This cap will continue to be reviewed during the weekly Joint Technical Committee meetings (JTC) between ZRA and the two power utilities