Press statement by the Zambezi River Authority on the water levels at Kariba Dam
Zambezi River Authority, being a Bi-National Organisation jointly and equally owned by the Governments of the Republic of Zambia and Zimbabwe, with the mandate to manage Kariba dam and develop additional water storage infrastructure along the shared portion of the Zambezi River located along the common border between the two Sister Republics, hereby wishes to provide an update on the water levels at Kariba Dam.
The water levels at Kariba are mainly influenced by the inflows into Lake Kariba from the Zambezi River and its tributaries located in the Kariba catchment. The Authority has 14 gauging stations located within the Kariba catchment and among these are the Chavuma and Victoria falls gauging stations which are key in the monitoring of inflows into lake Kariba. The recorded flows at the two stations are detailed as follows.
Flows Recorded at Chavuma
The Zambezi River flows rose from 236 m3/s at the start of January 2020 to a peak of at 5,006 m3/s recorded on 25th February 2020 after which the flows receded. However, the Zambezi River at Chavuma Station is known for its double peaks in flows and has accordingly again begun to increase. As of 27th March 2020, the river flow was at 4,559 m3/s while last year same date it was 732 m3/s. The obtaining river flow at Chavuma has continued to trend above the long-term average of 2,005 m3/s by One Hundred and Twenty-seven percent (127%).
The recorded flow at Chavuma is higher than that recorded on the same date in 2019 by Five Hundred and Twenty-three percent (523%). The current flows at Chavuma are so far the highest in the last twenty years. However, there is a four (4) weeks’ time lag for the flows at Chavuma to reach Victoria Falls owing to the significant influence of the Barotse Flood Plains situated between the two stations. The Barotse Flood Plains are now full and the flood waters have now began to arrive and increase the flow at Victoria Falls.
Flows Recorded at Victoria Falls
The Zambezi River flows monitored at Victoria Falls rose from 349 m3/s at the start of January 2020 to 3,890 m3/s recorded on 27th March 2020. Last year on the same date the recorded flow was 800 m3/s. The flows are now Fifty-four percent (54%) above the recorded long-term average flow of 2,522 m3/s for this station.
Water Levels at Kariba
The lake level rose by 97cm between 1st January 2020 and 27th March 2020. This recorded increase in the lake levels at Kariba is attributable to the improvement in the inflow from the Upper Kariba Catchment.
As of 27th March 2020, the recorded lake level at Lake Kariba was 477.64m, signifying 14.86% live storage or 9.63 Billion Cubic Meters (BCM) of usable storage with the lake being just over 2m above the Minimum Operating Level (MOL). However, this recorded volume of stored usable water is Sixty (60%) lower than that recorded on the same date last year at a lake level of 480.73m with 24.16 BCM or 37.28 % usable storage with the lake being 5m above the MOL.
During the period October 2019 to Mid-March 2020, the total inflow into the Lake stood at 10.54 BCM when the historical average for this period is no less than 14.39 BCM. The below average inflow recorded to date under the 2019/2020 rainfall season accounts for the low water levels that continue to be recorded at Kariba.
Water Allocation and Power Generation at Kariba
The Authority allocated 22 Billion Cubic Meters to be shared equally between the two power stations at Kariba, effectively limiting the combined power generation output to an average 550MW (or 275MW for each of the two power plants at Kariba). The Authority has maintained this water allocation for the remainder of the 2020 period in the wake of the below average lake inflows under the 2019/2020 rainfall season in an effort to ensure build up the reservoir storage.
The Authority will continue to monitor the hydrological situation in the Kariba Catchment and water levels at Kariba Dam and keep the public accordingly informed.
ENGINEER MUNYARADZI C. MUNODAWAFA
27th March 2020