LARGELY due to climate change, South Africa is becoming drier from the west to the east. Climate modelling for our area shows that our annual precipitation (rainfall) will reduce by between 10% and 15% at current warming levels. As a result, along coastal areas fresh water has to be transported from further and further afield to meet the demand of ever-growing urban areas. This has become a worldwide challenge, and around the globe researchers and scientists have being looking at the use of technology to increase the supply of fresh water.
Proposals include towing icebergs from Antarctica to water-stressed regions, cloud-seeding, desalination plants and extracting fresh water from deep submarine aquifers.
A longstanding proposal beginning in the late 1970s has been to tow icebergs from Antarctica to supply fresh water to water-scarce regions of the world.
One major challenge to this proposal has been how to tow the icebergs towards the equatorial zone without them melting before reaching their destination.
Cloud-seeding is a process in which dry ice or potassium iodide particles are used to increase rainfall. Although there is little scientific evidence that this actually works, many communities faced with water shortages are willing to try it.
There is also some legitimate fear that without proper research cloud- seeding could backfire, causing environmental catastrophe.
Desalination is the process of removing the salt impurities and other dissolved minerals from bodies of water. Currently, about 4000 such plants dot the globe, mostly located in developed countries. One of the main challenges of desalination is that it uses high amounts of energy and is therefore expensive to operate.
Closer to home, it was recently confirmed that during the search for oil and gas off our coastline, fresh water was found under the sea bed in submarine aquifers. According to the group Deepwater Water Research, an exploration well offshore of Port Elizabeth intersects a potentially abundant supply of potable water at a depth of 3km, and 60km out to sea. They claim this resource alone has the potential to produce 50 million m³ of water a year.
It seems the reason for these submarine aquifers is the geological sequence known as the “Table Mountain group” which basically acts as a giant sponge and runs deep under the surface in this part of the country. It is likely that there could be a number of these aquifers under the sea bed off our coastline.
The proposal (and feasibility studies are under way) is to drill into these aquifers and then pipe and pump this water to the shore. This should certainly be explored as a means of restocking our diminishing water resources. We do, however, need to look at the costs associated with such extraction, especially the environmental impacts.
No matter how many technical advances are made, we cannot change our need for water. We have to share that need with the plants and animals that we depend upon. Water will continue to be a scarce resource and research and water extraction will become more expensive.
The issues involved with water scarcity will never be solved by a technical “fix” alone. We must also take into account that as we humans seek to alter nature and its natural course, we could trigger other reactions. It is a sad reality that we are going to see many lesser developed countries become more deprived, as the cost of fresh- water utilisation grows.
Whatever the best solution is to this problem, surely the most prized goal would be to conserve, optimally utilise and recycle what we already have? – The Herald
– Bravo Andrew! Need I say more?