Coal and Gold Mining
Coal and gold mining causes acid mine drainage (AMD) as water reacts with sulphides in the ore and rock, making sulphuric acid. Acid dissolves toxic metals more easily than neutral water, and these metals damage the health of people, livestock and fish in the rivers. Acidic water can generally not be used to irrigate crops and runs the risk of contaminating ground water.
Leaking Waste Water Treatment
Leaking, spillage or flooding of waste water can result in completely untreated sewage entering rivers, streams and dams. This contamination has significant negative impacts on water quality, biodiversity and human health. Notably, waste water contamination in our water source areas can enhance the spread of diseases such as e-coli, diarrhea and hepatitis A.
Hydraulic fracturing or ‘fracking’ associated with natural and shale gas extraction poses significant threats to our water source areas. Potential negative impacts on water quality include stress on surface water and groundwater supplies from the withdrawal of large volumes of water, contamination of ground and surface water resulting from spills or faulty well construction and adverse impacts from discharges into surface waters or disposal into underground injection wells.
Climate change is hitting South Africa harder than countries in the north and is being felt first through water impacts. Higher temperatures will mean that plants need more water, evaporation rates increase and algal blooms are more likely to make the water in dams unusable.
Land degradation happens when land is over-used, over-grazed and poorly managed. Water runoff increases, transporting nutrients and soil from poorly managed crop and range lands into rivers and wetlands. Degraded land cannot recover easily from inevitable droughts and floods.
Large-scale plantations of pine and wattle use much more water than natural vegetation cover and reduce stream flows. Where plantations are poorly managed they can further reduce available water to other users and are a source of invasive plants.
Irrigation is South Africa’s largest water user and reduces water availability to others. Large-scale cultivation of mono-crops such as sugarcane can reduce the amount of water available in rivers, wetlands and aquifers. These crops use more water than the natural vegetation and accordingly may reduce stream flow.
Fires are a part of the natural life cycle. Today we are seeing a very high frequency of fires, which doesn’t allow enough time for natural ecosystems to recover; and results in soil erosion which then clogs up rivers and dams.
Alien plants (black wattle, pine) invade landscapes, outcompeting natural plants. They reduce the natural biodiversity, degrade ecosystems and use more water than indigenous plants. Roughly 3% of South Africa’s available water resources are lost to alien plants.