The Zambezi River Authority (ZRA) says there are no plans to open floodgates of Kariba Dam now despite improving inflows.
ZRA chief executive Munyaradzi Munodawafa said Lake Kariba is now above the minimum operating level of 475.50 metres but it will take more inflows for the waterbody to reach its full capacity. Said Munodawafa:
The lake current level recorded on 2nd March 2021 of 480.76m does not warrant any need for spilling.
As is the case for dams with the design such as that of Kariba dam, there is a Rule Curve under the Standing Operating Procedures (SOP) for Kariba dam that governs Kariba reservoir operations and guides as to when spilling would be required.
The current lake level is way below the rule curve limits of maximum storage for this time of the year and therefore, this implies that there is room to store incoming floods in the reservoir.
Therefore, as the lake level recorded on 2nd March 2021 falls way below the Rule Curve limit, the Authority will not undertake any spilling soon.
… The lake is not yet at its full capacity. When at full capacity, the lake level is 13m above the MOL with live storage at 100% with 65 billion cubic metres of usable water
The latest update from ZRA showed that its water elevation as of 2 March 2021 had risen to 480.76 meters. ZRA said:
From the last update made on 19th January 2021, the lake levels have increased by a total of 3.96 meters from the lake level of 476.80m recorded on January 19th to a lake level of 480.76 meters recorded on 2nd March 2021.
Lake Kariba’s sluice gates were opened to relieve pressure in 2001, 2009, 2010 and 2011.
The floodgates are usually opened where there are heavy rains in the Zambezi catchment area, particularly in Namibia and Angola.