Why worry about groundwater?

Making the invisible visible: A chat with groundwater expert Dr. Karen Villholth, Principal Researcher, IWMI

Interviewed by Samurdhi Ranasinghe, Senior Communications Officer, IWMI

Farmer using an electric water pump to pump groundwater for his plantation. Photo: Hamish John Appleby / IWMI
Farmer using an electric water pump to pump groundwater for his plantation. Photo: Hamish John Appleby / IWMI

In 2022, groundwater is not only the focus of World Water Day, but also a key area of emphasis in the U.N. World Water Development Report. But why should we worry about this water below our feet, a resource that is largely out of sight and out of mind?

To answer that question, IWMI recently spoke with groundwater expert Dr. Karen Villholth to learn more about the ways groundwater can serve as a lifeline to help us more effectively navigate the escalating climate crisis.

With more than 30 years of experience in the field of groundwater, Karen has worked with IWMI for 13 years — first based at IWMI headquarters in Sri Lanka, and then later in South Africa. She has worked on advancing groundwater sustainability at both the local and international levels, and describes her work to date as a series of long hauls to have groundwater receive greater recognition as a fundamental asset for the survival and resilience of people and the planet.

Karen’s capacity-building efforts and partnership cultivation have helped bring groundwater to the forefront of the development agenda in Africa, through the support of the African Ministers’ Council on Water (AMCOW). She highlights this as a major recent achievement: “There is now a long-term and high-level commitment in Africa to invest resources in building infrastructure and institutional capacity for its sustainable development,” she says, emphasizing that efforts to strengthen “water security, food security, and resilience are badly needed.”  Given its centrality to many of the U.N. Sustainable Development Goals (SDGs), groundwater “is an invisible piece of the puzzle to resilience, sustainability, and natural ecosystems,” she adds, “more important today than ever.”

Continue reading below to learn more about what Karen has to say about this vital resource.

  • Why should we bother about groundwater?

“Groundwater is indispensable for an estimated half billion people in sub-Saharan Africa.”
Groundwater is a vital resource that provides almost half of all domestic water worldwide, serves about 38% of the world’s irrigated land, and about one-third of water required for industry. It sustains ecosystems and maintains the river flows during dry seasons. It prevents seawater intrusion and ground subsidence, like sink holes. Groundwater is also an important part of climate change adaptation and is often the alternative source of water during drought and other disasters. We are all dependent on groundwater. That’s why we must care about its sustainability.

  • How does groundwater become a solution for people without access to safe water?

Groundwater is key to survival of humans, livestock, wildlife, vegetation, and ecosystems. It is widely available, under the ground, and even in dry areas. For example, in Africa, most rural communities rely on groundwater as their main source of water. It goes without saying that maintaining these resources and the infrastructure to secure safe access to groundwater, like wells and boreholes, is crucial, especially for women who otherwise spend significant amounts of their productive time collecting water for their households. Groundwater is indispensable for an estimated half billion people in sub-Saharan Africa.

  • Does groundwater play a crucial role in mitigating climate change?

Naturally, groundwater provides a more climate-resilient resource. It remains protected underground from extreme heat. It is accessible to tie over dry or drought periods, as long as it gets replenished again during the wet seasons. This leveling out of dry and wet spells is the key virtue of groundwater in combatting climate change. It’s not rocket science, and has been used for millennia in traditional cultures and even by animals who have learned to dig for water. The innovative part of groundwater and climate change adaptation today is that we ‘engineer’ groundwater access and replenishment to suit our needs, e.g. through dedicated drought infrastructure and managed aquifer recharge, and this is something we will see a lot more of.

  • Is the quality of groundwater getting better or worse?

“Treat our land as if there was a precious treasure underneath”
Groundwater quality is generally deteriorating because of the pressure from human development, urbanization, and intensification of agriculture. What were once mostly issues in developed countries, we are now also see in developing countries. Soil and groundwater have a natural capacity to ‘self-remediate’ poor water quality through various processes. But the current level of pathogens and chemicals seeping uncontrolled into the ground is making these processes insufficient. And in return this has alarming consequences for people’s health and the environment. It is estimated that nearly 1,000 children under the age of five die every day due to preventable water and sanitation-related diseases. At the same time, coastal aquifers, upon which half a billion people rely, are increasingly under threat as groundwater is being pumped more intensively, worsened by sea-level rise, leading to flooding and salinity from the sea entering the previously freshwater sources. This may destabilize economic growth in these regions. Groundwater can retain hazardous human-induced chemicals ‘under cover’ for many years, only to show up in critical ecosystems where significant harm can occur. Our chemical footprints, from new forever-chemicals, are undermining the health of humans and ecosystems in the long term, and groundwater often becomes the long-term sink that captures these pollutants. What to do? We must treat our land as if there was a precious treasure underneath (there is!) and ban non-degradable chemicals.

  • Will we ever run out of groundwater?

No, we will not run out of groundwater. But we may run out of easily accessible and fresh clean groundwater, making its availability and access increasingly difficult and costly. Prevention, to avoid depletion and degradation, is the key. We leave a very poor legacy for our children if we do not act today. We are increasingly seeing new, often little-replenished reserves of groundwater being developed as demand increases. Humans will increasingly strive to settle in areas where groundwater is secured and well-managed for the foreseeable future. Wealth will prove to follow where there is good groundwater, but this may also entice competition as groundwater tends to be the last resort. Hence, there is the need for more proactive and adaptable approaches.

  • What are the major threats to groundwater depletion?

“It is estimated that by 2050, we will need to grow 60% more food to feed a world population of 9.3 billion”
The major threat to groundwater depletion is intensive pumping for agriculture in arid and semi-arid areas, where groundwater is not being replenished naturally at the same rate. This is seen across a lot of the major food-producing areas in the world and is a growing concern for global food security. This is increasingly acknowledged but needs a lot more attention by policymakers across the world. Shifting diets and shifting production methods and geographies for food production will have to form part of the solution.


Solar-powered irrigation in Kenya Photo: Jeffery M Walcott / IWMI
Solar-powered irrigation in Kenya Photo: Jeffery M Walcott / IWMI

  • Can the agriculture sector function without groundwater?

Groundwater is essential for food production. The water gap arising from increasing food demand over the last half century has to a large extent been filled by groundwater, in a mostly unrecognized — and unsustainable — manner. As this resource is increasingly tapped, with no new easily accessible freshwater resource alternative available at the scale of groundwater, it is clear we have to think creatively and find new solutions to support the ever-increasing food demand. It is estimated that by 2050, we will need to grow 60% more food to feed a world population of 9.3 billion. Also, water demands for food are increasingly being trumped by water demand for urban areas and industry, so agriculture has to step up to use groundwater more sustainably, proper groundwater-sensitive economic incentives have to be put in place for farmers, recycling our waters must be prioritized, and at the same time we all limit our ‘foodprint’.

  • Can you highlight some of the solutions?

“Groundwater has to be visible to all. Policy makers have to see groundwater as a solution broker, rather than simply a problem to be ignored.”
We need a ‘multi-pronged’ approach, which brings groundwater front and center to development and climate action planning. This was made clear at COP26 and the World Water Forum in Dakar in March 2022. Managing our groundwater stocks as valuable accounts that are resilient to climate change in the short term but possibly vulnerable to climate change in the long term, is the first step. To do this, we need — besides monitoring and predicting climatic changes —  to keep track of the stock, monitor the groundwater levels and quality on a routine basis, and use novel direct technologies or more indirect or airborne technologies. This is part of making groundwater visible and hence manageable. Priority investments into groundwater as part of adaptation will prove to be no-regret. We have heard about sponge cities, water harvesting, recharge enhancement and protection (or artificial drainage where groundwater flooding occurs), and water markets or rationing: All of these are approaches and technologies that aim to maintain a healthy water balance underground. These approaches need to be actively implemented and incentivized through various means, such as payment for ecosystem services, legal measures, urban planning, community-based processes, and technological and IT advances coupled with enforceable regulations. We must also remove economic incentives that undermine groundwater, e.g. through free or cheap energy for pumping. On the other hand, we must make energy accessible in locations where groundwater is available but where people also suffer from ‘economic’ water scarcity.

  • What is being done right now, and is it enough?

“The groundwater crisis and the climate crisis have many similarities and are closely linked. They need to be solved together”
Obviously, it’s not enough! Sustaining our groundwater is a defining challenge of our lifetime, along with the climate crisis. From the personal level and then on to the local and global levels, we have to take an active stance on groundwater. We can all do our share. Personally, you can be a champion of groundwater, maybe start in your backyard where you could harvest rainwater and take pressure off the public water supply system, or at local level, avoid intentionally or unintendedly dumping chemicals or dangerous waste. Build overall awareness at all levels. Groundwater has to be visible to all. Policymakers have to see groundwater as a solution broker, rather than simply a problem to be ignored.

  • How can we accelerate global action for sustainable groundwater management?

We know the issues. Now we need the attention of global leaders and decision makers. In the inland food bowls of China and the USA, which produce almost 40% of the global food, groundwater is running out. Economic drivers will help shift production to new potential areas, like South America and sub-Saharan Africa, but we cannot move huge delta populations and need to find local solutions.

Achieving the SDGs requires that groundwater is developed and managed properly, with priority for 1) basic supplies for domestic use, WASH, and small-scale productive uses in poor countries; 2) protecting critical groundwater-dependent ecosystems (GDEs); and 3) ensuring global food production. Including more explicit and well-formulated criteria for groundwater sustainability in global development goals are also needed, like the present one for SDG 6.4.2 on environmental flows. Others need to follow, e.g. on how much countries are doing in terms of protecting their land, GDEs, and actively enhancing and managing groundwater recharge.

More economic and political incentives need to be developed and put in place, similar to carbon credits. This is an unexplored field with potential going forward. The groundwater crisis and the climate crisis have many similarities and are closely linked. So they need to be solved together. After all, countries and regions that manage their groundwater resources sustainably will enjoy water security and resilience deep into the future, even under a changing climate.

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