Major South African city sinking into a state of disaster

·1 Mar 2025

Centurion and the surrounding areas are slowly falling away as it faces a sinkhole crisis, with calls to declare the situation a national state of disaster.

The City of Tshwane is grappling with a significant sinkhole crisis, particularly in Region 4, which encompasses Centurion and Laudium.

According to the MMC for Cooperative and Shared Services Kholofelo Morodi, approximately 58 of the 61 identified sinkholes in Tshwane are located in Centurion.

She added that the sinkhole problem is due to its dolomitic landscape, which is highly susceptible to ground collapse, especially after heavy rains and water leaks.

Morodi noted that the municipality’s severe financial constraints make addressing the problem challenging.

She said the tight budget compounded the issue by competing with demands for service delivery, such as water and electricity provision, employee salaries, and payments to Eskom and Rand Water.

“Currently, the budget allocated to address the sinkholes is R14 million, which is insufficient compared to the estimated R200 million required to resolve the issue in Region 4 alone,” Morodi said.

“To address the crisis, the municipality plans to formally request the National Government to declare the sinkhole situation a National Disaster.

“Doing so would enable access to additional funding from the national disaster centre needed to fix the existing sinkholes plaguing the city,” she added.

The MMC also emphasised the importance of residents adhering to regulations, particularly the prohibition of borehole drilling in the area, as it exacerbates the formation of sinkholes.

According to Pretoria Rekord, residents have expressed their concerns about the frequency of such occurrences.

“The increasing number of sinkholes in Centurion is troubling,” said a Lyttelton resident, Nathaniel Scheepers.

The discovery has also sparked discussions online, with residents sharing photos and voicing their concerns across social media platforms.

Many worry about potential infrastructure damage and safety hazards should the hole expand or new ones develop.

Centurion’s big problem

According to a paper published in the Journal of the South African Institution of Civil Engineering, almost two-thirds of the Centurion CBD area represents a medium hazard for sinkhole formation.

However, almost a third of the area is considered high-hazard, and only a small portion (5%) represents low-hazard conditions.

Prof J Louis van Rooy of the Department of Geology at the University of Pretoria told Times Live that the dolomitic soil in Centurion is a significant factor in the frequency of sinkholes.

“The dolomite bedrock is not only pure dolomite, but there are other rock types like chert interlayered, which don’t dissolve, and other elements are left after the dolomite dissolves.

These materials are now loosely filling the voids, and the cavities may also be filled with soil falling from the surface,” said Van Rooy.

“This is then a metastable system, and if there is a cave or large void deeper down, heavy rains or concentrated water inflow from a burst pipe may mobilise the loose void infill into the deeper cavity, creating a sinkhole when the void appears on the surface.”

He said the main actions should be to prevent water from leaking into the possible sinkhole area, prevent further inflows from stormwater, and reroute waterborne services.

Van Rooy said areas where sinkholes occur were developed many years ago, and over time, waterborne services deteriorate.

“Residents need to look out for surface cracks that may indicate soil movement, not overwater gardens, and look out for leaking taps or wet soil patches that may indicate subsurface water leakages.

“The city needs to mitigate risk by keeping services up to the standards as prescribed, replacing ageing and leaking services, and generally managing surface stormwater to prevent concentrated inflows,” he said.

The City of Tshwane further stated that a delegation of officials, including the Regional Head, Chief of Emergency, and other city officials led by the MMC deployed to Region 4, completed a critical on-site assessment of the five largest sinkholes in Region 4.

“This inspection, which included municipal officials, emergency services, and experts in environmental management, underscores the administration’s immediate commitment to addressing this ongoing problem,” the city said.

“The administration has already begun implementing safety measures and is developing a comprehensive plan to restore and protect the region.

“This collaborative effort involves all relevant stakeholders and focuses on delivering concrete solutions for the communities most affected by the sinkholes,” it added.

The city reassured residents of Region 4 that the administration is fully engaged in resolving this issue and that swift and decisive action is being taken to protect lives and infrastructure.