Lots of talk on social media about the volume of the Falls at the moment - some are even claiming highest levels in seventy years - tourism media hype or reality? Zambezi River Authority data shows river levels at the Falls have experienced an early rise in levels, and levels are high, with flow rates exceeding 4,000 cubic metres a second, but within normal ranges and by no means exceptional. The trend is much as per 2019-20, which also experienced an early peak to similar levels, followed by a second peak in June (but not many people experienced this high season due to the global pandemic). It remains to be seen whether this year will follow with a similar second peak.
The 2017/8 flood cycle experienced a slightly higher peak, but later in May, while 2009/10 recorded a yet higher 'double peak' (but still below 5,000 cubic metres/second) and 2008/9 recorded an even higher early peak (exceeding 5,500 cubic metres/second). Individual years prior to this date are not shown, with the long-term mean indicated by the dashed red line (partially obscured by subsequent data), but the exceptional flood years of 1977/8 and 1968/9 are shown, when flow rates exceeded 6,000 and 8,000 cubic metres a second respectively. The highest recorded flood levels at the Falls was 11,600 cubic metres/second in March 1958 (not shown on hydrograph).
What is abundantly clear from the hydrograph is the extreme variability in seasonal flow over the Falls - from lows of 300 cubic metres/second to highs of 3,000 cubic metres/second, and huge variability in annual flood levels, reflecting variability in seasonal rainfall across the vast upper catchment area of the Zambezi River. What is of particular note from the hydrograph is that 2023-24 was an exceptionally 'flat' year, with peak flows hardly exceeding 1,000 cubic metres/second.
Source: Zambezi River Authority website.

