Why groundwater needs stewardship

Clean, fresh groundwater is essential for drinking water, agriculture, industry, nature, and the energy transition. Yet both quality and quantity are under growing pressure from population growth, pollution, and a changing climate. The dry summers of 2018 to 2022 offered a stark illustration: across the Netherlands, streams ran dry, foundations were damaged, and agricultural losses ran into the hundreds of millions. A pattern increasingly seen in regions around the world.

TNO develops reliable 4D information products that show not just where groundwater is, but how conditions are changing over time. Through tools like Groundwater Levels in View and Groundwater Quality in View, we provide accessible, real-time insight into current groundwater conditions, trends, and future scenarios. With the open-source model Everest, we help optimise extraction locations to balance competing demands on the resource.

Groundwater systems respond slowly to change. The effects of a prolonged drought on water tables may only become fully apparent years later, while recovery after a wet period can take equally long. This slow-motion dynamic demands early informed action.

Across multiple fronts, pressure on groundwater systems is increasing. Falling water tables lead to salinisation, threatening agriculture and drinking water supply. In built-up areas, shifting groundwater levels cause foundation damage and subsidence. Extreme rainfall puts pressure on the balance between surface water and groundwater. Future climate scenarios, both for the Netherlands and globally, point to increasing pressure on groundwater systems and with these impacts set to intensify.

Addressing these challenges requires reliable data, integrated system knowledge, and decision support that connects science to practice. TNO develops the knowledge, tools, and decision-support frameworks that enable more robust and adaptive groundwater management.

Drawing on national subsurface data from the BRO, the hydrogeological model REGIS II, climate scenarios, and the open-source model Everest, we provide the evidence base stakeholders need to plan for a future where groundwater systems remain resilient and reliable in the face of climate change and broader socio-economic developments.

The subsurface is getting crowded. Drinking water extraction, geothermal energy, aquifer thermal energy storage, industrial cooling, agricultural irrigation, and groundwater-dependent nature all compete for the same space. These uses interact in ways that are not always visible. A thermal storage system, for instance, can alter groundwater chemistry and affect drinking water extraction in the surrounding area.

TNO develops 4D decision-making frameworks, decision-support tools, and innovative technologies that enable stakeholders to weigh competing interests, reduce risks, and make coordinated use of the subsurface.

Considering groundwater alongside other subsurface functions such as geothermal energy, aquifer thermal energy storage, and carbon storage. In doing so, we help unlock the full potential of the subsurface, while ensuring it is used responsibly and sustainably for current and future generations.

Effective management of groundwater resources depends on timely, reliable, and actionable information. Groundwater Stewardship at TNO develops advanced information products, from 4D subsurface models to decision-support tools and data platforms, that cut across all pillars of groundwater stewardship. These products form the backbone of our work, enabling stakeholders to act on the best available subsurface knowledge.