Groundwater is increasingly used as a key source of water for both human consumption and economic activities. Around the world, it provides nearly 50% of drinking water, 40% for irrigated agriculture and 35% for industries. However, population growth, pollution and climate change are putting more and more pressure on global groundwater reserves. To protect this irreplaceably precious natural resource, it is essential to develop improved groundwater management systems.
What is groundwater?
Groundwater is water that fills the spaces and cracks between rocks, sand and gravel found underground. These underground layers that allow water to flow through are called aquifers. Groundwater is naturally refilled by rain or melting snow that seeps in from the surface. The water in aquifers can flow out to the surface through springs or feed into lakes, rivers and other ecosystems. People also pump groundwater from wells to use for drinking, farming and other needs.
Why is groundwater important?
Groundwater can supply water for towns and cities, and support industry and agricultural activities like irrigation, livestock raising and inland aquaculture.
A naturally climate-resilient resource due to its availability year-round, groundwater is protected underground from extreme heat. Groundwater can be drawn upon during dry seasons or drought, but only if it is carefully managed — the amount taken out should not exceed the amount naturally replenished. When this balance is maintained, groundwater becomes a valuable and reliable resource.
Groundwater is also extremely important for ecosystems. It provides a year-round base-flow to streams and sustains Groundwater Dependent Ecosystems (GDEs), which range from desert springs to mountain meadows and streams, to coastal wetlands and forests. According to a World Bank study from 2024, 60% of these GDEs coexist with pastoral land, making groundwater vital for wildlife grazing and livestock.
What challenges threaten groundwater supply?
Human activities — like clearing forests for farming, pollution and climate change — are putting groundwater and aquifers at risk in urban, industrial, rural and even natural environments.
Typically, groundwater is protected from pollutants by overlying soil and rock layers. However, shifts in land use and growing industrialization can increase the risk of contamination from chemical or biological pollutants coming from septic tanks or wastewater.
Some types of rock and soil naturally contain minerals like arsenic, fluoride and salts which can slowly dissolve into groundwater and make it unfit for certain uses. Over time, these hazardous chemicals can end up in vital ecosystems and pose serious health risks to humans through prolonged exposure.
Climate change will also significantly impact groundwater supply. As climate change makes water availability more erratic in many places worldwide, groundwater pumping has intensified to overcome shortfalls caused by inadequate surface water supply or to make up for insufficient rainfall. It will also impact other physical characteristics that contribute to groundwater recharge and supply, such as foliage patterns and surface water to groundwater exchange. Rising sea levels driven by climate change may also cause saltwater to seep into groundwater in coastal areas, making it unfit for human consumption and agriculture.
How can we better protect groundwater?
Managing groundwater quality and quantity is essential to maintaining a safe water supply for all. Preventing pollutants from reaching groundwater is a better management strategy than attempting to clean it up after, as decontamination is often expensive and time-consuming.
Establishing monitoring systems to inform groundwater basin modelling and management helps policymakers and researchers get a better understanding of the available resources and how best to allocate them. This can be done through direct technologies, such as sensors placed in wells, which record water levels and pressure, or through indirect or airborne technologies, like drones or satellites.
To protect groundwater stocks, it is essential to develop comprehensive and coherent groundwater management policies, particularly when groundwater is shared across administrative boundaries. This allows governments and consumers to better prepare for droughts and other potential disasters.
Groundwater management interventions cover different aspects of the groundwater system, from supply enhancement to demand control, quality protection and governance or institutional measures. Potential investments into groundwater include harvesting rainwater to replenish groundwater stocks, managing aquifer recharge and protection, developing water markets or rationing, implementing contamination prevention measures and building sponge cities, which are urban areas designed to collect, retain and use rainwater by replicating the natural hydrological cycle.
Governments and other stakeholders can strengthen groundwater management through incentives such as payment for ecosystem services, urban planning, legal frameworks and regulatory enforcements. They can also protect groundwater supplies by removing economic incentives that encourage its exploitation, such as free or cheap energy for pumping water.
Ultimately, safeguarding groundwater will require a multifaceted approach that includes both comprehensive monitoring and sound management plans to ensure its sustainable use and long-term resilience.