The hydrological impact of the rewatering of the Gemsbokfontein dolomitic compartment on the Wonderfonteinspruit

Abstract

Water is an essential resource for any life on earth but water is also the most poorly managed of all resources. Many countries are facing a water crisis and South Africa is no exception. The dolomitic groundwater compartments of the West Rand and Far West Rand are one of the most important aquifers in South Africa. The problem is that the area houses some of the richest gold mines and most of the compartments have been dewatered resulting from the mining activities. The Gemsbokfontein Dolomitic Groundwater Compartment is one of the five regional groundwater compartments and North Shaft, Harmony Gold Ltd is situated within the compartment. The mine has reached its life span in 2002 and there is a possibility that the mine can be flooded. This will result in the Gemsbokfontein Compartment being flooded and will eventually decant into the Wonderfonteinspruit. The objectives of this study was to determine the rate of recharge of the compartment and the volume of discharge at the decant point. The results showed that the compartment would take between 5.8 years and 46.19 years to flood and that the flooding rates are sensitive to the effective porosity of the zones modelled. Once the compartment is filled, it will start to decant at the original 14 mL/day and flow into the Wonderfonteinspruit. Once the compartment starts to flood, the model will have to be redefined with the measured parameters.