19-06-2025
Deadly Mthatha flood underscores worsening factors increasing risks for SA
As South Africa reels from another deadly flood, this time in the Eastern Cape, we take a look at the bigger picture of the nation's vulnerability. Floods are the country's most common weather disaster, with intense cut-off low weather systems, probably amplified by climate change, repeatedly causing devastation.
After the devastating and deadly flooding that hit Mthatha and other parts of the Eastern Cape last week, people are still searching for missing loved ones, particularly children, and trying to salvage their belongings and homes.
Mussa AjiDa said that they were still searching for his child, Simbongile, who went missing after the school transport Simbongile was travelling in was swept up in the Mthatha flooding on Tuesday, 10 June 2025.
AjiDa was forlorn and exhausted when he spoke to Daily Maverick. Simbongile had still not been found, more than a week after 13 learners were swept away in the devastating scholar transport disaster. AjiDa said the search would continue until Simbongile had been found.
This is just one among several cases playing out as South Africa responds to this most recent flooding incident, driven by heavy rainfall in a cut-off low weather system.
Minister of Human Settlements Thembi Simelane confirmed on SAfm on Wednesday, 18 June that on top of the 90 lives lost – including learners from the tragic scholar transport incident – almost 1,600 structures and 5,000 people had been affected by the recent Eastern Cape floods.
The immediate priority, she said, was to provide alternative accommodation to allow people to rebuild. But a significant challenge is the availability of suitable land, as many of the destroyed homes were built in unsafe areas too close to the Mthatha River, where rebuilding is not an option.
President Cyril Ramaphosa promised last week that the government would assist those affected and provide shelter after entire homes were submerged and washed away.
Year after year, parts of South Africa undergo significant flooding, wreaking havoc on housing, infrastructure, the environment and lives as the nation and communities attempt to build more resilient and responsive systems.
Increasing trend of weather extremes
Dr Stefaan Conradie, a climate science lecturer at the UCT Climate System Analysis Group, told Daily Maverick that recent flooding attribution studies suggest that rainfall from the cut-off low weather system along the east coast was probably becoming more intense due to climate change.
In other words, climate change is likely exacerbating rainfall and causing devastating flooding in eastern South Africa. This was evidenced by the World Weather Attribution study on the 2022 KwaZulu-Natal floods.
South African Weather Service (Saws) meteorologist and weather forecaster Lehlohonolo Thobela told Daily Maverick that there was an increasing trend of weather extremes over the central and eastern parts of the country, especially with many adverse weather conditions linked to heavy rainfall affecting KwaZulu-Natal and the Eastern Cape.
In this case, an intense cut-off low weather system developed in the upper atmosphere on Sunday, 8 June, as forecast by Saws. Conradie said that as it moved across the eastern escarpment and south-east coast, a very intense surface low-pressure system developed roughly beneath it.
This drove extremely strong winds that also transported a lot of moisture off the still relatively warm Agulhas Current region.
'Extremely heavy rainfall and destructive wind gusts resulted, particularly in the early hours of Tuesday, 10 Jun, over the eastern parts of the Eastern Cape,' said Conradie
Multiple intersecting factors result in these kinds of disasters; weather and climate are only one aspect of that landscape.
'The adverse weather conditions in the Eastern Cape were because of the cut-off low that began by affecting the Western Cape and the Northern Cape from 7 June 2025. The weather system progressed to the eastern parts of the country and started to cause havoc over the Eastern Cape from 9-10 June 2025, Monday and Tuesday. The adverse weather conditions lasted for the week, with the emergency teams still helping. The weather system exited the area by Wednesday, 11 June 2025,' said Thobela.
The areas over the central and eastern half of the Eastern Cape that were hit the hardest, recorded more than 50mm of rainfall water depth in 24 hours – Mthatha recorded 149mm, Port Alfred recorded 51.6mm and Makhanda (formerly Grahamstown) recorded 93.6 mm.
But rainfall was not the only factor that escalated the disaster. Following an assessment by the Department of Water and Sanitation, engineers determined that the Mthatha flooding was exacerbated by two simultaneous events.
On Monday, 9 June 2025, the Mthatha Dam was already at 99.8% capacity before sudden upstream rains raised its level to 102% by midnight, causing it to spill. At the same time, the Cicira River tributary, located downstream from the dam, was also experiencing flash floods.
The department said that it was this combination of the dam's spillage and the heavy, independent flow from the flooded tributary that caused the Mthatha River to overflow its banks.
Floods most common disasters in SA and Africa
A recent study, published in May 2025, analysing weather-related disasters in South Africa from 1980 to 2023, found that floods and storms are the most common disasters in the country, with the highest number of incidents reported in KwaZulu-Natal.
The research, which used the Emergency Events Database, also identified the primary weather systems driving these events.
It was conducted by researchers from the University of Pretoria, the Global Change Institute at the University of Witwatersrand, the University of Limpopo, the South African Weather Service and others.
Their analysis revealed that the eThekwini metropolitan municipality in KwaZulu-Natal recorded the most disasters during this period, while the Cape Town metropolitan area had the highest number in the western region of South Africa. In Gauteng, the most populous province in the country, Johannesburg saw the highest number of floods, and Ekurhuleni had the most storms.
This aligns with what has been experienced across the continent – flooding has been the leading natural disaster in African countries for decades.
The study found that floods were the most reported disaster type, with 49 occurrences, followed by storms with 33. Droughts and wildfires were the next most common, with 11 and 10 events, respectively.
When it comes to the geographic distribution of these, the eastern part of South Africa, particularly KwaZulu-Natal, experienced the highest frequency of both floods and storms. The Cape Town metro was a hotspot for droughts.
When it came to what has been driving the weather systems causing these, the study linked flood and storm disasters to eight types of synoptic weather systems.
Cut-off lows were the most significant, causing 48 of the reported disasters. Upper troughs were the second most influential, responsible for 15 disasters. Ex-tropical cyclones were linked to four disasters during the 43-year period.
Cut-off lows were also responsible for the Heritage Day floods in Cape Town in 2023 and the Nelson Mandela Bay floods of April and June 2024.
The researchers found that the concentration of disasters in metropolitan areas such as eThekwini and Cape Town suggests that human factors such as urbanisation may amplify the impacts of extreme weather events.
The research was based on data from the Emergency Events Database, which has specific criteria for including an event, such as 10 or more deaths, 100 or more people affected, a declaration of a state of emergency, or a call for international assistance.
The authors noted that while their study provided a comprehensive overview, the reliance on the Emergency Events Database could lead to an underestimation of disaster events, particularly in rural areas where reporting may be less consistent.
The study concluded that mid-latitude, mid-tropospheric systems were the primary drivers of flood and storm disasters in South Africa; it is hoped that these findings enhance the understanding of weather-related disaster risks in South Africa for better climate resilience and proactive disaster management.
Thobela said the most important lesson they were learning was to make sure there was better communication with the affected communities and to make sure that there were more community engagements that taught about being proactive about weather warnings, rather than reactive. DM
