As shifts in the climate of South Africa make some areas wetter and others drier, mines will soon have to deal with having too little water or too much. SRK Consulting partner and principal hydrologist Peter Shepherd warns that most mines are still not paying enough attention to the effects that climate change will have on their site infrastructure.
(Seen left: Peter Shepherd, partner and hydrologist, SRK Consulting.)
"Local research shows that changes in the global climate is affecting the way that local mines need to plan and build their infrastructure, particularly when it comes to water management," he says. "The need for a thorough review of specifications is becoming urgent."
According to studies by Lumsden and Shulze, climate change is going to be making the eastern parts of SA significantly wetter, and western regions drier. They predict that in the eastern areas of the country, mines will experience a disproportionate increase in the amount of water that is spilled into the environment. On the other hand, mines in the western parts will need to manage their water resources with greater care.
"Managing the on-mine water balance in drier areas is going to need better re-use strategies," says Shepherd. "Continued improvement is required in the design and implementation of ways to keep dirty water within the mine boundary, and to limit the amount of clean water that mines procure from municipal or other sources."
In areas where more rain is predicted, mines face the prospect of breaking the law if their infrastructure is not able to limit mine spillage into the environment surrounding the site. "Facilities in these areas must be designed or modified to account for the new parameters that climate change brings," he urges. "For instance, if a tailings dam is designed for a one-in-50-year storm event, and changing climatic conditions reduces this probability to one-in-20-years, then this can pose a severe threat to the downstream environment."
Using the Lumsden and Shulze research, SRK scientists Phillip Hull and Hediyih Ghassai predict that a 40% increase in rainfall could more than double the amount of contaminated water spilled by a mine into the environment.