Groundwater – real-world data on Africa’s hidden lifeline is lacking

By Bárbara Willaarts, Dor Fridman, Moctar Dembélé, Girma Ebrahim, Jonathan Lautze, Rebekah Hinton and Cebolenkosi Zuma

For communities straddling the border of Malawi and Mozambique, increasingly erratic rainy seasons are placing severe pressure on food systems and livelihoods. But there is a potential lifeline hidden entirely out of sight. Beneath the ground lies an unseen aquifer system that could keep crops alive and communities intact long after the surface rivers run dry.

In fact, the continent of Africa is estimated to hold roughly 0.66 million cubic kilometres of groundwater, a volume nearly 20 times greater than all the freshwater found in its lakes.

However, not all aquifers are created the same, making sustainable management highly complex.

In regions like North Africa, deep sedimentary basins beneath countries such as Libya and Algeria hold enormous volumes of water. Because these formations are highly porous and permeable, they can sustain large-capacity wells that drive urban expansion and large-scale farming.

Yet, there is a significant vulnerability. This is “paleowater”, deposited millennia ago, during a much wetter era. Trapped beneath impermeable rock, these deep reserves do not replenish today, meaning that their extraction is essentially a mining operation.

Further south, the hydrogeology shifts dramatically. Most of sub-Saharan Africa rests on hard, crystalline basement rock. Rather than vast porous sponges, these formations store water primarily in physical fractures and weathered zones. While these shallow systems cannot yield enough water for mega-farms or major cities, they do possess a critical advantage in that they are actively replenished by seasonal rains. This makes them ideal for supporting rural handpumps and small-scale irrigation, offering a renewable, decentralised defence against severe droughts.

Decoding a complex continental picture

The project Groundwater for Advancing Resilience in Africa (G4DR) — delivered by the International Water Management Institute (IWMI) and the Food and Agriculture Organization of the United Nations (FAO) with funding from the Global Environment Facility (GEF) – is trying to get a handle on this continental complexity .

G4DR works across Benin, Malawi, Mozambique, Togo and Uganda. The project is investigating groundwater availability across the continent and at key aquifers shared between different countries.  

At continental level, G4DR’s partner IIASA – the International Institute for Applied Systems Analysis  – is developing the GROW (Groundwater Risk and Opportunities in Africa) framework. Recognising that groundwater extraction is profoundly complex and multifactorial, GROW moves beyond simple geological maps. It overlays foundational hydrogeology — such as aquifer storage capacity and recharge rates — with vital socioeconomic and technical indicators, including population density, surface water scarcity and pit latrine use.

Map produced by the Groundwater Risk and Opportunities in Africa framework; Graphic adapted from: Dor Fridman/ IIASA.

By combining these diverse datasets, GROW highlights areas where groundwater extraction is feasible and could make a material difference to communities — while also red-flagging areas that pose risks if tapped.

For example, by measuring local groundwater recharge rates against basic domestic daily requirements (set at 30 litres per capita for rural populations), GROW highlights that 94 million people currently live in areas with a viable, sustainable drinking water opportunity. The map also shows that around 333 million Africans live in areas where groundwater could be sustainably used for irrigating crops, without seriously depleting aquifers

Conversely, by mapping high pollution probabilities against anthropogenic pressures, like livestock density, the framework reveals that 41 per cent of Africa’s population (535 million people) live in areas where reduced groundwater quality could pose a significant health risk.

Map produced by the Groundwater Risk and Opportunities in Africa framework; Graphic adapted from: Dor Fridman/ IIASA.

These various maps are now being incorporated into a dynamic, real-time interactive dashboard to give an unprecedented overview of groundwater in Africa.

Building local capacity

But macro-level dashboards mean little without ground-truthed data. To unlock the potential of shared aquifer systems, G4DR is undertaking intensive, localised science.

In key transboundary regions — specifically the Mono River Basin (shared by Togo and Benin) and the Shire Aquifer System (spanning Malawi and Mozambique) — researchers recently completed a comprehensive inventory of existing groundwater monitoring boreholes. Rather than extracting water for daily use, these specialised observation wells provide vital data on the overall health of the aquifers.

G4DR project teams are currently in the process of upgrading these monitoring posts, installing modern piezometer dataloggers that can digitally track groundwater levels, temperature and salinity. In some cases, the teams are drilling new, purpose-built observation boreholes strategically positioned to ensure that both sides of the border benefit from the data.

The development of these cross-border monitoring networks and hydrological models is a joint process, driven together by the G4DR team and local water authorities in the respective countries. Similar participatory assessments and planning frameworks are also getting underway in Uganda’s Upper Nile Water Management Zone.

Translating data into action

By combining big-picture continental mapping with hard-won local data, the foundations are in place to track and protect these invisible waters. But even that doesn’t automatically translate into practical decisions. Science only secures the future when it is codified into actionable, funded policy.

G4DR is ensuring that insights and experience from the project are being directly wired into the continent’s new “resilience roadmap” — the Strategic Programme on Groundwater for Water Security and Resilience in Africa. Formally launched in April 2026 by the African Ministers’ Council on Water (AMCOW) alongside G4DR, this roadmap ensures that groundwater is no longer sidelined in continental economic planning. With the political and financial weight of the strategic programme, Africa has an unprecedented opportunity to safely tap its invisible lifeline and map a resilient future for its people.

Bárbara Willaarts is a senior research scholar in the Water Security Research Group at the International Institute for Applied Systems Analysis (IIASA).
Dor Fridman is a research scholar in the Water Security Research Group at IIASA.
Moctar Dembélé is a Spatial Hydrologist at IWMI.
Girma Ebrahim is a researcher on Hydrology and Water Resources at IWMI. Jonathan Lautze is a research group leader on Integrated Management of Basins and Aquifers at IWMI.
Rebekah Hinton is a research scholar in the Water Security Research Group at IIASA.
Cebolenkosi Zuma is a project coordinator for Groundwater for Advancing Resilience in Africa at IWMI.

More information:

• Environmental Research Letters: Quantitative maps of groundwater resources in Africa
• Abouelmagd, A. (2012): Toward a better understanding of palaeoclimatic regimes that recharged the fossil aquifers in North Africa: Inferences from stable isotope and remote sensing data
• Groundwater for Advancing Resilience in Africa (G4DR)
• International Institute for Applied Systems Analysis (IIASA) – Water security
• Strategic Programme on Groundwater for Water Security and Resilience in Africa