Burst dam walls, cars trapped in bumper-high water and a raging Jukskei River were caused by a heavy overnight storm in Gauteng.
Pictures of flooded roads and a rugby field under water in Krugersdorp were shared on Twitter on Friday morning, all of which showed the seriousness of the storm.
According to Monument High School staff members, a nearby dam burst its banks, flooding the school sports fields and several classrooms.
Pupils at the school had to vacate the premises.
Principal Johann Calitz said the damage had been caused by the overflowing Key West Dam just up the road.
“There were no injuries luckily. We are still estimating the cost of the damage,” he said.
The rain and the excess water from the dam started to overflow from about 6am.
The Key West Dam has no surrounding walls to stop its overflow.
Traffic authorities and emergency services were gearing up to deal with flooding after several crashes were reported overnight.
“This storm is in a band coming from the north, through Botswana and North West,” said SA Weather Service meteorologist Bransby Bulo.
He said the thundershowers were expected to last in Gauteng until about Monday or Tuesday, before moving to northern Free State and Mpumalanga.
The Joburg Emergency Management Services said the rain had caused several crashes.
In about an eight-hour period, they had responded to 10 incidents in Joburg but there had been no fatalities, said the service’s spokesman, Robert Mulaudzi. However he said there had been several injuries.
The Johannesburg Roads Agency released a flash-flood warning on Friday morning, saying people stuck in their cars made up 80 percent of flood drownings.
“This often happens when drivers underestimate the dangers of navigating through flood waters,” said JRA managing director, Skhumbuzo Macozoma.
“Especially at low-lying bridges, where as little as 30cm of water is enough to float most vehicles.”
Macozoma urged motorists not to attempt crossing flooded bridges and said that if their car stalled, they should immediately get out and go to higher ground.
Netcare 911 paramedics responded to two separate crashes since last night. In the first, one person was killed in West Village in Krugersdorp and several were critically injured.
The second crash involved a truck and five cars this morning on the N3 eastern bypass near Marlboro Drive in Sandton. Four people were seriously injured.
The JMPD said the major problem areas on the roads included the double-decker highway section of the M1 in the Joburg CBD, the M1 between Carr and Smit streets in Newtown, the M1 south towards the Empire Road offramp and New Canada Road under the railway bridge near Riverlea.
In Soweto, the corner of Khumalo Main and Klipspruit Valley roads as well as Mtipa Street in Orlando were problem areas, Joburg metro police spokes-woman Edna Mamonyane said.
Google’s live traffic service showed traffic was extremely slow in and around the Joburg CBD and along the N3 south from Linbro Park to Voortrekker Road in Alberton and the R24 and N12 from Boksburg approaching the Gillooly’s Interchange.