The future of groundwater

Today, about 2.2 billion people lack access to safely managed drinking water services and 3.6 billion people lack safely managed sanitation services. The latest World Water Development Report (WWDR) tackles groundwater, which has remained under the radar for far too long.

By Yazeed van Wyk

Groundwater is a major water-supply source and provides almost half of all drinking water worldwide. While it delivers roughly 40% of water for irrigated agriculture, this figure can be much higher considering that half the water flowing in rivers comes from groundwater as baseflow. Furthermore, groundwater provides about a third of the water supply required for industry and also sustains biodiversity and terrestrial ecosystems. It is a strategic resource and an important component to adapt to the threats associated with climate change.

Despite these impressive statistics, groundwater is out of sight and often out of mind for most people. Human activities (including population and economic growth), poor land-use planning and climate change are putting pressure on groundwater resources. Serious depletion and contamination problems are reported in many parts of the world due to this lack of understanding, including in South Africa.

Locally, groundwater plays a pivotal role in ensuring water security. It supplies approximately 13% of the total water supply but often provides up to 100% of supply to some areas. It is thus a resource of strategic importance. The Water Research Commission has been a driving force in setting the research agenda for groundwater in the country for just over half a century. A core focus is to promote, create and disseminate

Yazeed van Wyk, national treasurer: Ground Water Division, GSSA

knowledge and innovation on the optimal and sustainable utilisation of South Africa’s groundwater resources through coordinated research activities.

Increased dependence on groundwater

Cities internationally are becoming increasingly reliant on groundwater and, right now, roughly 50% of all urban populations worldwide rely on groundwater. This dependence will intensify, particularly in the rapidly urbanising areas of developing countries and emerging economies.

As dependence on groundwater increases, how sustainably can it be used?

As an example, how many cities are sinking faster because of aquifer compaction (over-abstraction) than

sea level rise? This is something that has never been published in an Intergovernmental Panel on Climate Change report, showing that cities are sinking because of groundwater over-pumping. Cape Town is actively developing the Table Mountain Group (TMG) and Cape Flats aquifers to increase long-term water security. This is in direct response to the unprecedented multi-year drought that dramatically reduced surface run-off into the main water supply dams. The drought serves as a case in point and gives us a sense of how we are on a definitive trajectory to a drier climate and that we will reach the 1.5°C average rise in global temperatures a lot sooner than expected.

Managed aquifer recharge

A key intervention for adapting to climate change and to secure and augment the current water supply has been the practice of managed aquifer recharge (MAR). South Africa has advanced significantly in this regard, with a national map showing the prospects for MAR, an artificial recharge strategy on how to develop MAR projects, and well-documented case studies (e.g. Atlantis, Hermanus and Elandsfontein). However, the pace of MAR implementation in other areas has been slow and this could be because of a lack of awareness of and experience with MAR, financial resources, human and institutional capacity, enabling policy frameworks, sufficient and sufficiently wellfunctioning demonstration sites, and poor understanding of aquifer hydrogeology and geochemical properties. Another challenge that will need to be looked at from an MAR perspective is the role of the shallow unsaturated zone thickness, as there is a concern that some bacteria, viruses or parasites could survive and contaminate groundwater.

Groundwater professionals

The research that has been developed and implemented through Water Research Commission studies demonstrates that the know-how and technological solutions exist to address the many challenges we are facing in sustainably developing groundwater as an alternative mix to surface water. However, the general lack of groundwater professionals among the staff of institutions and especially at local government level, as well as insufficient mandates, financing and support of groundwater departments or agencies hamper effective groundwater assessment, monitoring, planning, development and management. Siting and constructing the higher-yielding boreholes that are necessary for large-scale irrigation or town supplies in complex hydrogeological environments require considerable expertise. In addition, how we procure for professional groundwater development services is an area of concern.

Improved knowledge, capacity building and training are not enough; to protect aquifers, we also need innovation, in terms of technical interventions, institutional and legal reforms, improved financing, and behavioural changes. Individuals, researchers, governments, NGOs, civil society, the private sector and, indeed, the entire international community need to make groundwater more visible. It is necessary that we work together to ensure each country can assess and sustainably manage its water resources. We are counting on you all to engage actively in our efforts to make groundwater visible in 2022 and beyond, and educate the next generation of groundwater industry leaders.