A study by the Council for Geoscience has identified long-term risks from over 120 years of gold mining in the Klerksdorp, Orkney, Stilfontein and Hartbeesfontein region.
The research links groundwater dewatering and rewatering from underground mining to sinkholes, ground subsidence and acid mine drainage in the dolomitic geology of the KOSH area in North West.
Council for Geoscience representative Nomvelo Mkhize explained the process. “Dewatering and rewatering affects the environment which is dolomitic and has cavities that get filled with water. If you remove the water you are creating a cavity, a void and then there will be a collapse.”
The findings highlight how the pumping of groundwater for mining operations acts as a key trigger for these geohazards.