‘Burrowing like dinosaurs’ to find water
The desperate quest for groundwater in the Karoo can be compared with the way the dinosaurs started to burrow 230-million years ago, Gift of the Givers geologist Dr Gideon Groenewald said.
“Just as they burrowed to escape heat and drought, we are doing the same thing to look for water,” he said.
The dinosaurs, of course, went extinct, and while the future of humankind was not as definitively grim as that, people were living in perilous times, he said.
“We are right now in the midst of the sixth mass extinction where we are seeing the worst spate of species die-offs since the loss of the dinosaurs 65-million years ago.
“Global warming and the drought we are seeing here in places like Graaff-Reinet and Adelaide are part of that phenomenon, which is sweeping the planet.”
Groenewald, whose geology PhD focused on the palaeo-environment of the Karoo, spent most of his career working as a researcher with SANParks before becoming a consultant to disaster relief group Gift of the Givers.
Asked about the sustainability of continuing to sink an increasing number of boreholes and harvesting an increasing volume of groundwater, he said it was a concern.
“Absolutely it is important. But we are in survival mode.
“We can’t do it forever, but as a humanitarian I cannot say no if I have the means to help a child, especially.”
With that outlook, the aim in Graaff-Reinet was to sink the first boreholes at schools.
“The aim is to put in a borehole at each school.
“Many of them are on high ground so it will not be easy, but if there’s nothing available at one school we will pipe water across from the next one.
“We want to ensure 5l of drinking water a day for each of the 6,534 kids and 684 teachers in Graaff-Reinet.”
Groenewald said communities in arid areas should all be moving away from flush toilets to dry compost toilets.
“Politically and socially we are not at a point where we can all accept that, but this borehole initiative of ours anyway will not be to supply water for waterborne sewerage.”
The good news was that even with climate change, a fierce storm would at some point arrive and, because of the geography and geology of Graaff-Reinet, the water table would be quickly recharged.
“Run-off from the volcanic rock on the high ground will replenish the Sundays, the Pienaars and the Gats and seep down into the groundwater system.”
Explaining how he pinpointed good borehole sites where many other hydrologists had struggled, he said it started with high altitude aerial photographs which he studied to pick up “linear patterns” reflecting subterranean cracks left when Gondwana split 170 to 180-million years ago.
Focusing on the best looking ones, he then shot another round of aerial photographs at a much lower level to ensure these natural patterns were from rocks and plants and not a fence, road or even an old oxwagon track.
Rainfall seepage collected in the cracks so thereafter, using instinct and scientific apparatus, it was a matter of determining size and accessibility.
“It takes concentration and meditation,” he said.