A new study from the University of the Witwatersrand and the University of Brighton in the United Kingdom has confirmed that the April 2022 floods were likely the most catastrophic natural disaster recorded in KwaZulu-Natal, in terms of the lives lost and overall economic impact.
Exactly one year ago this week, KwaZulu-Natal was hit by devastating flooding that claimed the lives of 459 people, destroyed more than 4 000 homes and left 40 000 people homeless.
In April last year, the KwaZulu-Natal coastal zone, including the greater Durban area and South Coast, received more than 300mm of rain in 24 hours.
By the end of May last year, 88 people were still missing and 45 000 people were temporarily left unemployed. The cost of infrastructure and business losses amount to an estimated $2 billion.
According to the study, the heavy rainfall that triggered the flooding and mass movement events was “reported in national and international media as having ‘smashed weather records’. However, no systematic and up-to-date flood record exists for KwaZulu-Natal to allow the April 2022 floods to be viewed within their full historical context”.
Trawling historical rainfall records
The study presents an historical geographic account of flooding in the province, with a particular focus on the greater Durban region. Stefan Grab from the School of Geography, Archaeology and Environmental Studies at Wits University and his colleague, David Nash, constructed a geographical history of flooding disasters in KwaZulu-Natal.
They sifted through thousands of archived articles held in old newspapers, colonial and government records, early missionary records, and meteorological records, which became available from the 1850s onwards.
They define extreme flooding events, where major rivers were overflowing their banks, together with one or more significant consequences, such as the loss of human life, livestock, agricultural fields and crops, and infrastructure such as buildings, roads and bridges.
Significant flood events
In their study, they document 53 significant flood events from 1850-1899 (an average of 1.1 per year) and 210 from 1900-2022 at an average of 1.7 per year.
“Within the limits of our data, we suggest that the frequency of flooding in Durban has likely doubled over the last century,” the authors said, noting that their research confirms that the April 2022 floods were “likely the most catastrophic natural disaster yet recorded in KwaZulu-Natal, in collective terms of lives lost and overall economic impact”.
“Right after the floods, many commentators like the media, some scientists and others were quick to report that the floods were the most severe ever recorded,” said Grab, the lead author.
“Our aim was to place the floods into perspective and see if this and other statements related to the disaster were factually correct by building a historic geographic account of past floods and associated extreme rainfall events for the province of KwaZulu-Natal and particularly the greater Durban region.”
‘Not the biggest’
The scientists found that while the floods were indeed the most catastrophic in terms of lives lost, infrastructure damaged, and economic loss, the flood was not actually the biggest in terms of the area affected, homes destroyed, or the amount of rainfall that fell collectively over a few days.
“When you look at a natural disaster you need to look at it in context,” Grab said. “Whether the April 2022 floods were the ‘worst in living memory’ is debatable, as a flooding event in September 1987 affected a larger geographic area of KwaZulu-Natal and destroyed more homes than the 2022 event.
“Similarly, a catastrophic flooding event in Durban, 1856 – also in April – produced a greater quantity of rainfall over a three-day period than last year’s floods.
In April 1856, 303mm of rain fell in Durban over 24 hours, and a record of 691mm over a three-day period from 14 April to April 16. During these historic floods, an unknown number of people drowned, the entire central area of Durban was flooded, bridges were destroyed and roads were closed for several days, cutting off all communication with other parts of the country.
The floods extended inland to Howick and the Umgeni bridge was swept away. Over a 16km stretch of beach, between the mouths of the Umgeni and Umhlanga rivers, 200 drowned oxen were deposited.
Grab said that it’s difficult to compare the two floods in terms of which was the most severe. “We must recognise that back in 1856 Durban was only a town with a much smaller population and economic infrastructure to that of today, and thus the percentage of individuals impacted or percentage economic loss may well have been greater back in 1856. In addition, coping mechanisms and ‘outside’ support would have been far more restricted during the 19th century.”
Global warming
According to the authors, it is highly likely that recent human-induced global climate warming has contributed to trends of increased flooding as they had demonstrated in their study. This trend is likely to continue in the foreseeable future.
“However, it is also important to recognise that catastrophic climate events such as severe floods are not temporally restricted to a ‘warmer world’ as the 1856 floods happened during a much colder climatic period,” Grab said.For flood disasters, history is repeating itself, he warned. “We need to prepare for bigger rainfall events in our cities, and that doesn’t just apply to Durban, it applies to all South African cities and towns. We must get our infrastructure, especially drainage systems, in order. It is urgent that we better prepare ourselves for the heavy rainfall and flood events that are guaranteed to come in times ahead.”
