GROUNDWATER
Groundwater: hidden but never forgotten
Part of the Geological Society of South Africa (GSSA), the Ground Water Division (GWD) is a body of scientists and technicians who have an interest in the optimal development of South Africa’s groundwater as a limited natural resource.
important to monitor your own borehole water quality and levels.
Fanus Fourie (FF) National Chairperson, GWD
Yazeed van Wyk (YW) National Treasurer, GWD
How much groundwater is used in South Africa? FF Between 13% and 16% of the nation's total water supply originates from groundwater. However, this would exclude all boreholes that are not registered at the Department of Water and Sanitation. YW In some areas, groundwater provides up to 100% of the water supply. How much local data is available on groundwater? FF The DWS monitors approximately 1 800 boreholes around the country and has issued in the order of 25 000 wateruse licences. As a borehole user, it is
54
JUL /AUG 2021
YW The Water Research Commission developed a study called the Strategic Water Source Areas (SWSA) of South Africa, showing that 50% of the water comes from just 10% of the land area. There are 57 SWSA-gw (groundwater) – about 11% of South Africa’s total water – with 37 of these being nationally strategic. The SWSA-gw supply 32% of the settlements that get more than half of their supply from groundwater (and house 4% of the national population). They supply 44% of the groundwater for agriculture, and 32% of the groundwater used for industrial purposes in South Africa. Groundwater is also the main source of water for a further 268 settlements in South Africa. This is significant. Is groundwater an underutilised resource? FF Yes and no. Yes, because 7.5 billion m3 per annum of groundwater is available and there is 10 billion m3 per annum of surface water, but almost all of the surface
water is fully allocated. Around 19% of all groundwater is found in KwaZuluNatal, but most of the province’s water is sourced from a river or a dam. Groundwater is definitely underutilised in KwaZulu-Natal. South Africa is currently using around 50% of available groundwater and still can develop the other 50%. But if a community has a river, it will not go to the expense of drilling a borehole to utilise available groundwater. There is around 2 billion m3 per annum of groundwater that can be developed. On the other hand, groundwater is not underutilised. In fact, it is overutilised in places like the Karoo. Groundwater has massive potential. Cape Town will be pumping roughly 10 Mℓ/day of groundwater. Once Port Elizabeth’s groundwater scheme is in place, roughly 15% to 20% of all its water will come from groundwater. Groundwater in Brandvlei in the Karoo is pumped as far as 50 km from the town. Many towns and communities are supplied solely from groundwater. In certain cases, we can utilise more groundwater; in other cases, we need to focus on protecting our groundwater.
