The changing story of groundwater science (extract from Geobulletin)
The changing story of groundwater science (extract from Geobulletin)
Guest Editorial by Matthys Dippenaar Associate Professor: Engineering Geology and Hydrogeology Department of Geology, University of Pretoria
We need nice stories about science, so we don’t have to perpetually defend science in a world flooded by intentional misinformation and misrepresentation of skill.
As geologists we face this constantly when we share the fascinating stories of the origin of the Universe, the history of the Earth, and the development of Life. We sometimes face different, more real-life and close-to-home matters, where conflict is not necessarily due to differences in narrative, science education or belief. Here, science becomes a surrogate for issues pertaining to moral, ethical, societal and monetary injustice: energy, land use, mineral resources and groundwater—all fundamentally geological resources.
What makes water supply different to minerals and energy, however, is that water is a basic human right. This implies that water is supplied at extremely watered-down tariffs to make it accessible and affordable to all. While this is both commendable and absolutely necessary, it does result in reduced respect and appreciation for the resource.
People tend to be more wasteful of something because it is free or cheap, making water management and governance a very difficult task indeed.
Most of us grew up with a friendly schematic version of the water cycle. A smiling water droplet accompanied you on a spectacular journey from a cloud to rain, and from a river to the ocean. With arms outstretched it yearned to be pulled up to the skies again to complete the circle of its existence.
Occasionally—rarely, but occasionally—we would see this droplet acknowledge the other 99% of the planet’s fresh water. You would be so lucky to be accompanied to the ice caps and glaciers where water is in solid phase, or underground where water stays in openings in soil an rock as groundwater. Though two thirds of our freshwater occurs as ice and one third as groundwater, humanity is still biased towards that 1% occurring in rivers and dams. Almost all fresh terrestrial water is practically excluded from the narrative.
When we look at the story that is told, it is one of reservoirs to store surface water. When that runs out, we talk of augmentation by desalination of ocean water. Whatever happened to the water that we walk on, that shows some delayed response to climatic extremes, and that has some lower vulnerability to contamination and evaporation losses when compared to most surface water alternatives?
This is why no one blinks an eye when boreholes are drilled at random and at one’s own prerogative. As long as the dam levels are monitored, the use of your groundwater is deemed your privilege—no, your right!—despite it being fundamentally wrong and in direct contradiction with our National Water Act (NWA; Act 36 of 1998).1 The Act states very clearly that water is a natural resource that belongs to everyone and that—despite its uneven distribution—its use should be equal. This is echoed by our Constitution (Act 108 of 1996), which states implicitly that everyone has the right to sufficient water, and an environment protected from pollution and ecological degradation, and subject to sustainable development.
Abuse of cheap water affects the story of groundwater. When the sound siting and installation of water infrastructure outweigh the ‘free water’ you are looking for, then why in the world would you spend more on doing it legally, sustainably and ethically? Why would you opt for geophysics and models and testing when someone knows someone who has a gift and can do it for less? This makes it very hard for well-trained groundwater scientists to compete with fairy tales of dowsing (or divining or witching; whatever hocus pocus term works). Science has been given a bad name.
It is a story so often told; one of the abilities of some individuals to site groundwater by some obscure means. But finding water is not the hard part. Practically all ground is wet at some depth. This is the premise of gravity, whereby water (or anything, for that matter) will go down as long as there are openings for it to go down into. No scientist has ever contested that. Finding water is not the skill.
Finding clean water, at acceptable yields, that will not adversely affect the environment or other users, both in space and time, and that will not falter in its yield—this is the skill. Doing this all subject to the SANS 0299 series (Code of Practice: Development, Maintenance and Management of Ground Water Resources), and subject to water use licensing requirements (NWA 36:1998)—this is the skill. This is where the science trumps the quackery, and where we need to be more forceful in protecting the water cycle from those without any respect of it (read, those who shamelessly mine or over abstract water, or those who knowingly pollute it).
This is where groundwater science comes in.
Hydrogeology or geohydrology (used synonymously for most purposes), the scientific study of groundwater, is a fairly well-established science with its roots very close to early-days civil engineering, geophysics, and of course, geology. It has developed to a science no longer concerned solely with water supply from boreholes (or wells), but to one understanding the complexity of the hydraulics of aquifers and its place within the greater water cycle.
No, we don’t just pump boreholes. And no, groundwater doesn’t come from underground rivers and lakes. It is more complex than that. I’d encourage everyone to start with the book by Nel 2 and then to work through the amazing free online platform of groundwater science information at the Groundwater Project (https://gw-project.org).
We need to study the mechanics of the aquifer to understand the regional ramifications of lower watelevels in boreholes. We need to understand the substantial significance of allowing water quality to deteriorate at one point in the water cycle.
Numerous cities and towns throughout South Africa are dependent either fully or partially on groundwater in the water supply mix. 3,4,5 Urban groundwater also brings with it so much more than just matters of supply, also requiring input into water-related disasters, flooding, flooding of underground infrastructure, sustainable drainage solutions, and so much more.6,7
Cities are very often founded on or near water to serve as transport corridors, or for nutritional (drinking) purposes. Cities are near coastlines or rivers. Yet Gauteng is on top of a significant water divide in South Africa, diverting surface water to the Indian Ocean by means of the Crocodile, Olifants and Limpopo rivers, as well as to the Atlantic Ocean by means of the Vaal and Orange rivers. The founding of Pretoria, which predates the discovery of gold and the founding of Johannesburg, is deeply rooted in the high yielding springs from the Malmani Subgroup in the present-day Fountains Valley Resort. As you enter the capital city from the Fountains Valley Interchange, you are greeted with fountains, reminding us of the two high-yielding springs around the corner. To this day, these two springs (Upper Fountain and Lower Fountain) supply in the order of a combined 30–40 million litres per day to Tshwane. The discharge from the springs has remained constant for the 160 years since its first use, and they now supply 5–10% of the City of Tshwane’s water, together with some other springs and boreholes.
Unlike the karst springs in Pretoria, Cape Town itself has a number of springs associated with the Table Mountain Group that have contributed to the water supply of the city throughout its history. Even though the hydraulics of these springs is different from the karst springs in Pretoria, they also provide consistent discharges of remarkably good water quality.
One should never waste your word count with things everyone knows. Yet this needs to be said: South Africa is water scarce. South Africa’s water is erratically distributed. South Africa is predominantly semi-arid to arid.
None of this matters. We have to make do with what the complex geological and geomorphological development of our country has left us, and how this is further compounded by the climate and the changing climate. We have to make do with the difficult job we have as hydrogeologists, and how this is further compounded by ignorance and miscommunication. We need scientists who can communicate science through stories that will captivate audiences and convert those who fall prey to dishonesty and misrepresentation.
Maybe the water cycle also deserves some herd immunity; an additional layer of care and resilience where it is possible, to attempt to mitigate possible adverse effects elsewhere where it is more vulnerable...
Hydrogeology is a fascinating science that South Africa is remarkably competent in internationally. Our hydrogeologists are well respected abroad, and we contribute to academic research, collaborative research, and the international professional bodies. As a country, we are hosting the 50th Congress of the International Association of Hydrogeologists in Cape Town as a joint partnership between its South African National Chapter and the Ground Water Division of the Geological Society of South Africa, in 2021. This is the third on the continent and the second in the country. What a wonderful opportunity to showcase our country’s competence in the science of groundwater!
Hydrogeology is becoming increasingly important. The amount of work done by hydrogeologists in augmenting water supply during the recent droughts is astonishing. These teams spent months to years with geophysical investigations, field visits, modelling, hydraulic testing, and sampling to come up with water supply solutions that are sustainable in the long-term. As hydrogeologists, one needs to test and monitor to continuously verify and improve models. While these are very easily and very often neglected, the consequence of untested and unmonitored schemes is inevitably failure at the expense of the environment and the people. Water supply is as much a matter of drilling a borehole as driving is a matter of having a key, and doing it wrong is an enormous risk.
We no longer study and teach borehole drilling. The hydrogeologist of the twenty-first century has to manage the resource to ensure long-term sustainability and equitable access to the benefit of the people and the environment.
As scientists, we need a partnership with the public and a partnership with the environment. Our client is the Water Cycle, and it is becoming increasingly volatile in a time of climate change, brownfields developments, urbanisation and emerging contaminants. We should update the narrative; our stories should not only say that (groundwater-)science is fun, but that it is hard and that it requires skill and competence.
1. NWA. National Water Act 36 of 1998. Government Printer.
2. Nel M. (2017). Groundwater: The Myths, the Truths and the Basics. SP 108/17. Water Research Commission. Pretoria. Available online at www.wrc.org.za.
3. Dippenaar M.A. (2013). Pretoria’s Fountains - Arteries of Life. SP 44/13. Water Research Commission. Pretoria. Available online at www.wrc.org.za.
4. Dippenaar M.A. (2015). Johannesburg: Gold in the Rand, Water from the Land. SP 91/15. Water Research Commission. Pretoria. Available online at www.wrc.org.za.
5. Dippenaar M.A. (2016). Cape Town: where sweet Waters meet the Sea. SP 95/16. Water Research Commission. Pretoria. Available online at www.wrc.org.za.
6. Armitage N., Vice M., Fisher-Jeffes L., Winter K., Spiegel A., Dunstan J. (2013). The South African Guidelines for Sustainable Drainage Systems. TT 558/13. Water Research Commission. Pretoria. Available online at www.wrc.org.za.
7. Seyler H., Witthüser K., Sunaitis M. (2019). Urban Groundwater Development and Management. 2741/1/19. Water Research Commission. Pretoria. Available online at www.wrc.org.za.