Unsustainable Farming A Threat To Water Supply

South Africa’s estuarine and wetland ecosystems provide important ecological functions such as the purification of water. Yet 99% and 88% of these ecosystems respectively are threatened. Prof Francois Durand of the Department of Zoology at the University of Johannesburg writes that farmers, who are the main water users in the country, have a crucial role to play when it comes to reversing this degradation.

- Prof Francois Durand

I have come across some horrible things in my years of research on the environmental damage caused by mines, but for me the most terrifying sight of all is a burning underground coal field.

There is very little that one can do to solve a problem such as this, because you will have to pump millions of litres of water into the coal field to extinguish the fire. It can be done in areas where the burning coal threatens lives and infrastructure, but it’s usually only a temporary and limited solution, as it will start burning again as soon as the water subsides, drains away or evaporates, leaving the coal to come into contact with air again and dry out.

AN IRREPLACEABLE RESOURCE

Now imagine what it would feel like to come across a similar situation in an area where there used to be a wetland. There are, at this stage, numerous underground peat fires in South Africa, and not a single farmer or forester responsible for them has been prosecuted.

Burning peat is caused by two factors: firstly, global climate change and, secondly, the farmer who responds to it. At present, the groundwater level is lower than ever in many areas, due to farmers’ increasing reliance on it for irrigation in the face of unprecedented droughts. For instance, in the Molopo area of the Northern Cape, the groundwater is at its lowest level in 7 000 years due to these factors.

Peat can only form under water, and when the water table drops, the peat is aerated and dries out, and will burn when exposed to fire in the same way the burning coal fields were set alight. The irony is that if the farmer extracts water to saturate the burning peat, the water table will drop even further.