Despite its semi-arid climate, the risk of flooding in South Africa is a growing concern and is now one of the country’s most costly natural hazards. Whilst seasonal flood events are expected in certain regions of the country, recent years have seen extreme flood events become more frequent and disruptive, causing major damage to infrastructure across the country and having significant impact on communities and the insurance industry alike.
The economic cost of flooding in South Africa
Linked to infrastructure damage and the slowing of economic activity, flood events in South Africa have created significant losses. Examples include the 2019 Durban floods, with estimated total damage costs of over $100 million USD (WillisRe, 2019) and the more significant 2022 KwaZulu-Natal floods, where infrastructure damage alone was estimated to be over $650 million USD (Reuters, 2022).
Learning from past events
The 2022 flooding of the KwaZulu-Natal region was one of the most extreme events in recent times where over 400 lives were lost across the province. The city of Durban was most significantly affected, with major infrastructure such as the port unable to function, and crucial highways blocked by debris (BBC, 2022). A lack of preparation for the flood event, in addition to rapid urban growth were suggested as key driving factors in the severity of this event, especially within Durban, which has extensive neighbourhoods in low-lying areas (JBA Risk Management, 2022), and one of the fastest growing populations in the country (Durban Edge, 2023), giving rise to informal settlements.
Putting flood maps to work
Understanding flood risk in South Africa through the use of high quality, up-to-date flood maps helps enable more-informed preparation and decision-making. High resolution maps can be especially important for improving resilience in regions where reliable data is historically scarce. JBA’s global flood maps are widely used by a range of international businesses and organisations to aid the understanding of flood risk. JBA has recently completed an update to its South Africa flood map which included a range of method improvements and covered areas inhabited by 73% of South Africa’s population, improving the reliability of flood map data across the country.
JBA flood maps can be used to easily identify the areas that are most susceptible to flood events. Whilst the return period of the 2022 KwaZulu-Natal floods would have varied spatially, on average it is estimated that the flood was approximately a 20-year event (World Weather Attribution, 2022). Using this information, along with JBA’s flood maps, the most vulnerable areas of Durban can be identified. Figure 1 shows a 20-year return period flood in Durban with surface water flooding displayed in purple and river flooding in blue.
Figure 1 indicates that the district to the south of Durban’s port is among the most affected. These were the areas affected by the 2022 KwaZulu-Natal floods, as evidenced in news reports which stated that the highways leading to the port were blocked and damaged, preventing trucks from accessing the areas (IOL, 2022). By using JBA’s South Africa Flood Map in this area of Durban, this knowledge could aid future planning efforts, reduce uncertainty around future events, and potentially reduce losses.
For comparison, Figure 2 shows a 500-year flood in the same area of Durban, indicating possible flooding from a more severe event. The map shows river and surface water flooding covering a much wider area, with potentially more significant impacts. But it is this sort of insight that can be used in advance of future events to mitigate impacts and help support planning and recovery.
If you are interested in JBA’s global flood maps, or require more information, please contact hello@jbarisk.com.
REFERENCES
BBC. (2022). Durban floods: South Africa floods kill more than 300. https://www.bbc.co.uk/news/world-africa-61092334
Durban Edge. (2023). Census 2022 insights into demographics, economy and potential. https://economy.edge.durban/data-story/census-2022-insights-into-demographics-economy-and-potential
IOL. (2022). Port operations affected as major damage caused to Durban road networks. https://iol.co.za/mercury/news/2022-04-13-port-operations-affected-as-major-damage-caused-to-durban-road-networks/
JBA Risk Management. (2022). https://www.jbarisk.com/knowledge-hub/event-response/south-africa-kwazulu-natal-floods/
Reuters. (2022). https://www.reuters.com/world/africa/rescuers-hunt-missing-after-south-african-floods-kill-more-than-400-2022-04-17/
World Weather Attribution. (2022). The Price of Natural Catastrophes in Africa: Insights into the most recent losses. Climate change-exacerbated rainfall causing devastating flooding in Eastern South Africa – World Weather Attribution
WillisRe. (2019). Summary of Natural Catastrophe Events 2019. https://www.willistowerswatson.com/-/media/WTW/Insights/2020/01/Willis-Re-Summary-of-Natural-Catastrophe-Events-2019.pdf?modified=20200128113240
World Resource Institute. (2025). https://www.wri.org/insights/managing-extremes-how-south-african-cities-are-tackling-water-crises