Aquifer alert: are we drilling to water disaster?


BURIED deep beneath Saudi Arabia are two fossil treasures: oil, of course, is one. Oil gave Saudi Arabia and other OPEC countries considerable leverage – remember the 1973 oil crisis?

Oil producing countries placed an embargo on oil supplies to the USA, the UK and other countries, including South Africa. By the end of the crisis, in March 1974, the global price of oil had quadrupled, from $3 a barrel to $12.

But Saudi Arabia feared that other countries might turn on it and exploit its weakness, an inability to feed its citizens. So in the 1980s, it decided to tap its other ‘fossil’ resource, water that had collected in an underground aquifer when the region was much wetter, some 20 000 years ago, to grow wheat and other crops.

After all, there were about 500 cubic kilometres of it under the desert, a staggering amount of water.

An estimated four-fifths of that is now gone, three decades or so later. With very little rainfall in the Wadi As-Sirhan basin where the crops are grown (100mm to 200mm annually), the aquifer has not recharged.

“A groundwater account is much like a bank account: if withdrawals exceed deposits, the account shrinks,” writes expert Sandra Postel in her 2017 book, Replenish. “Rarely monitored or regulated, groundwater depletion is the sleeping tiger of global water threats.”

It’s happening all over the world. The enormous Ogallala Aquifer is pumped to grow wheat in Great Plains states like Nebraska, Colorado, Kansas and Texas, producing altogether about one-sixth of the world’s grain. The water in the aquifer has been collecting since the end of the last Ice Age, around 15 000 years ago.

“By the beginning of the 21st century, a third of the world depended on aquifers for drinking water and farming. In China, plagued by drought, the North China Plain aquifer sustains 117 million people in Beijing and surrounding areas. […] aquifers in several of the world’s most productive, heavily populated regions are being drawn down at precipitous rates.

"NASA satellites, monitoring changes in Earth’s gravitational pull, found that 21 of the world’s 37 largest aquifers have passed the sustainable tipping point.”

When news broke that Beaufort West’s dam had run dry, the immediate response on a social media account I belong to was: why isn’t national government providing funds to drill boreholes? We do have large aquifer resources under the Karoo in the Karoo Basin, after all.

It’s a familiar response to water issues in a dry country – echoing Cape Town’s response to its crisis.

So here I am, banging on again about the realities of recharge: “…the recharge in the Karoo formations of South Africa varies between 2 and ∼5% of the annual rainfall”, that is 2% to 5% of an annual rainfall that ranges from 100mm a year in the more westerly and southerly parts to 500mm at best in the more north-east parts of the Central Karoo, and “recharge becomes negligible for rainfall lower than 400 mm” (Beaufort West gets about 160mm per annum, for example). 

And that’s now: predictions are that climate change will bring with it significant decreases in rainfall for the Western Cape and Northern Cape; that includes much of the Karoo Basin.

Drill, baby, drill and forget about next year

So do we “drill, baby, drill”, and risk the fate of the Saudi and other global aquifers in pursuit of water now, and never mind next year or the year after?

I say No. Not No to ever drilling – No to doing it blind, risking a resource which could, in the immediate future (I’m thinking the next three decades) be a crucial insurance policy for a country facing hugely uncertain water prospects.

“Poor data is a key problem. Big projects to map groundwater reserves are still ongoing, but there are few measures of how many people are taking water out. The government has traditionally relied on people’s goodwill to hand over that information.

"There is no national control over the drilling of individual boreholes, unless a municipality has a specific bylaw to that effect. Legislation only kicks in when it comes to the industrial use of borehole water. In effect, anyone can drill a hole in the ground and suck up as much water as they want.”

This is too important to mess around with, to do piecemeal and without attention and study. We’ve in effect done it that way for long enough, and where has it got us? Let’s start by making sure we understand what we have and how it’s already being used.

But we also need to have an urgent, transparent, non-partisan and inclusive conversation about water – right now.

Let’s call on everyone (citizens and scientists alike) for thoughts, research, ideas, from the small-scale but effective – water harvesting and greywater use in every house and business – to grand schemes: can we find ways of artificially recharging aquifers, as some places globally are doing with recycled water, for instance?

Should we consider evacuating people from some of the harder-to-supply small towns? Is it at all feasible to direct precipitation from extreme weather events into potential storage spaces underground – and how safe would that be?

Only air is more important than water. In a rapidly changing environment, we simply cannot afford to get it wrong.

  • Mandi Smallhorne is a versatile journalist and editor. Views expressed are her own. Follow her on Twitter.

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