South Africa is not near to exhausting its underground water resources – the view of hydrology experts and also the finding of the Water Research Commission.
A decade or more ago, it published a paper predicting that South Africa was heading for a water supply crisis… but that groundwater could play a significant role in bridging the predicted gap between water supply and demand.
Groundwater seen as strategic national resource
The paper said: “Groundwater is important, and undervalued and underused. It may emerge as the most important way in which any expansion in the agricultural sector is possible.”
The total volume of water stored underground in South Africa is estimated at around 235 billion cubic metres (m³) – and is in places like the geological formations, such as the massive Table Mountain group aquifer.
However, more than 90% of this water cannot be abstracted due to severe geographical, depth and geological constraints.
If South Africa were to maximise safe infrastructure abstraction, the maximum drinkable volume that could be pulled out sustainably sits between 12.6 billion and 14.8 billion m³ annually.
Warning against over-extraction risks
According to Groundwater and Geo-Environmental Solutions South Africa some years ago “pushing beyond this threshold risks severe environmental damage, such as sinkhole formation in dolomitic regions; seawater intrusion causing coastal aquifers to turn brackish and unusable and the drying out of local ecosystems”.
According to the International Groundwater Resources Assessment Centre, South Africa currently extracts between 2 000 and 4 000 million m³ of groundwater per year.
Because current usage only taps into a fraction of the renewable potential, groundwater remains an underutilised strategic resource to combat surface water scarcity across the country.
More than 400 small towns and rural settlements across South Africa rely entirely or partially on municipal borehole fields for their tap water.
Borehole drilling surges amid water failures
Driven by municipal “water shedding” and infrastructure failures, private suburban borehole drilling has exploded into a massive boom.
There is no single, definitive count for the total number of boreholes in South Africa, but there are at least hundreds of thousands currently in existence, with 80 000 to 100 000 new boreholes being drilled annually.
Because a vast number of private and residential boreholes go unregistered, tracking the exact number is a major challenge for water authorities.
The official database managed by the department of water and sanitation, the National Groundwater Archive, contains records for roughly 293 100 geosites.
This registry includes monitored boreholes, dug wells, springs and seepage ponds across the country.
District Municipality Mapping
Focused regional audits, such as data compiled in the Lets Respond Toolkit, have mapped out 79 374 distinct boreholes tied to specific municipal planning IDs.
The Borehole Water Association of SA believes the vast majority of newly drilled residential systems escape official archives.
