Can green infrastructure also protect foundations?
Dutch cities are increasingly facing foundation problems as a result of low groundwater levels, shrinking clay soils and land subsidence. Climate change is exacerbating these effects. At the same time, municipalities are investing more and more in green infrastructure, such as permeable pavements, rain gardens, swales and enhanced tree planting areas, to improve water management (drought, floodings), reduce heat stress, strengthen biodiversity and more . This raises an important question: what effect does green infrastructure have on soil conditions and foundations? Can it also contribute to protecting foundations?
To address this question, Deltares, in collaboration with municipalities and specialised companies, has launched the research project ‘Proactive Foundation Protection with Green Infrastructure’ (ProFundGI). The project investigates whether above-ground green measures can also influence subsurface conditions, helping to reduce foundation risks by regulating soil moisture and groundwater levels.
New role for green infrastructure
Green infrastructure is typically deployed as a climate adaptation measure, for example for water retention and cooling. However, its impact on subsurface conditions and foundations is still insufficiently understood.
We want to better understand how greening measures affect soil and groundwater, and whether they can extend the lifespan of both shallow and deep foundations.
Floris Boogaard, urban water expert at Deltares
The key lies below the surface
Foundation problems are often caused by changes in the soil. In areas with clay and peat soils, the ground responds strongly to fluctuations in moisture. During dry periods, groundwater levels drop and the soil shrinks, while in wet conditions it expands. These movements can lead to cracking and settlement.
Green infrastructure influences these processes, as it can either retain or drain water. This can help stabilise groundwater levels and reduce fluctuations, lowering the risk of subsidence and foundation damage.
We are bringing together two worlds – climate adaptation and foundation challenges – to explore where opportunities lie.
Nicoletta Nappo, foundation researcher at Deltares
Measurement, data-driven approach and practice
Deltares leads and coordinates the project, combining satellite observations, field measurements and geotechnical expertise. Techniques such as InSAR are used to accurately monitor ground movements, while soil moisture and groundwater levels are measured locally.
This combination enables a better understanding of how green infrastructure affects the subsurface. The insights are translated into an interactive GIS tool that supports municipalities in making foundation-aware decisions in spatial planning and climate adaptation strategies. In this way, the results are made directly applicable in practice.
From data to practical insights
The project partners are developing a validated monitoring approach, creating a standardised method that municipalities can apply. In addition, practical design and planning guidelines will be delivered for municipalities, engineers and infrastructure managers on how green infrastructure can be used to protect both shallow and deep foundations.
The project not only highlights the opportunities of green infrastructure but also identifies the conditions required for successful implementation. This includes assessing which measures contribute to more stable groundwater levels and improved foundation protection, and whether certain types of green infrastructure may have negative effects. For example, trees can extract water from the soil, potentially leading to increased drying.
Testing in Dutch cities
The research is being carried out in several Dutch cities, including Gouda, Groningen, Het Hogeland, Rotterdam, Utrecht and Amsterdam. These municipalities provide pilot locations, data and practical knowledge, and actively contribute to the development and validation of solutions.
Within the consortium, companies, knowledge institutes and government authorities work closely together. Partners include SkyGeo, Donkergroen, INDYMO, Polyciviel, RobbyTU, Aveco de Bondt, Waterketen in Beeld and Hanze University of Applied Sciences. Results are shared through publications and events, such as climate cafés and ClimateScan.
