January 20, 2005 By Bruce Venter
Tshwane Emergency Services evacuated the residents of three Centurion townhouses after a sinkhole threatened their safety.
The evacuations occurred in an Alethea Road complex at about 1am yesterday when the sinkhole opened, damaging three properties.
This is the second sinkhole in a Centurion housing complex in six months.
An emergency services official said yesterday's evacuations were necessary when it became evident that the five metre wide, three metre deep sinkhole posed a threat to the residents' safety.
"It was decided to evacuate the residents when it became clear the sinkhole was getting bigger and posing a threat to the houses," he said.
Sandra Rompel, who was evacuated with her two children to a friend's house, said the sinkhole was not the first at the complex.
"We have had sinkholes here before, but nothing as serious as this," she said.
The sinkhole, which is about two metres away from Rompel's bedroom wall, caused extensive damage to the paving and garden walls of the affected houses.
Rompel's neighbour, Suzette Pieterse, said residents were concerned that the sinkhole would spread.
"We are worried about more damage if it collapses further," she said.
Pieterse's property suffered slight damage in the incident.
An empty house was also damaged when a wall partially collapsed, causing the roof to crack.
Municipal workers were on site yesterday to fill the sinkhole and prevent it from expanding.
Municipal spokesman Ashika Sudu said the recent heavy rains had caused the sinkhole.
She said the sinkhole would be filled and compacted to prevent further damage.
"We will rehabilitate the sinkhole and clear away as much of the damage as we possibly can," she said.
Ian Anderson of Geo Scientific and Exploration Services said widespread residential and road construction had resulted in rain water being channelled beneath the ground surface in unusual quantities.
"These developments have interfered with the natural drainage system."
"Underground cavities are now being filled with excessive water, which erodes the soil, causing sinkholes," he said.
Anderson added that an extensive restructuring of the drainage system was needed to prevent the situation from escalating.
"Surveys of areas sensitive to sinkholes need to be done and where necessary, the drainage systems need to be restructured to move excessive water away from these areas," he said.
The following problems (service / traffic) are currently being experienced by Tshwane residents:
* There is a sink hole on the corner of Jogn Vorster Drive and Oak Rd
(Akkerboomln) in Highveld, Centurion.
Roads Division is attending to it. (Dec 2004 - Jan 2005)