Mayoral spokesman Samkelo Mgobozi said repair work was estimated to take nine months, not taking into account unforeseen delays. The work was likely to begin in the coming rainy season, Mgobozi said, and there could be delays due to the rainfall and wet ground, as well as availability of specialised equipment and contractor closure in December.
“The sinkhole has caused massive disruption to business and traffic flow in the area," he said. “This is the largest single cost of repair, and will also require a service provider with necessary capacity to undertake the work.
"Much of Centurion and Laudium are built on dolomitic soil, which is predisposed to collapse when coming into contact with a large concentration of acidic water. There are 24 sinkholes in Tshwane, of which 23 are in the Centurion, Laudium and Olievenhoutbosch region."
'Over the years Tshwane has not budgeted adequately for repairing sinkholes'
Mgobozi said that too repair all the city’s sinkholes at once was estimated to cost R60 million.
“We have committed ourselves to addressing the problem over the next financial years. However, site securing, geological investigations and periodic monitoring of the sinkholes are being done in the meantime.”
He said the city had also been approached by a corporate entity offering to assist in fixing the Jean Avenue sinkhole. A final assessment of the sinkhole repair method would be done within the next two weeks, and then the city would be able to determine how such generous offers could be used, according to Mgobozi.
He added that the biggest cost in fixing sinkholes was not merely the method and the material used to close the holes, but the relocation and reinstatement of service infrastructure that accompanied such a geomorphological disruption.
“The rehabilitation may also extend to the upgrade of services in the immediate vicinity surrounding the sinkhole,” he added.
Mgobozi said the other two sinkholes prioritised for repair as soon as possible were in Clubview - at a cost of approximately R3 million - which had the potential to affect 900 households, and 2nd Avenue in Claudius, at about R15 million.