Water quality time: students contribute to sustainable water management in the Utrecht region

From the Utrecht University campus the sloping landscape of the National Park Utrechtse Heuvelrug is visible on the horizon, an area stretching from the heather fields of Hilversum all the way down to the floodplains near the river Rhine. The many water bodies found across the Utrechtse Heuvelrug’s country estates are not only valuable from a cultural and historical perspective, but also offer a home to a great diversity of flora and fauna. But what about the water quality of these ponds, streams and pools? This is what Utrecht University students explored in the course Chemistry & the Environment of the Bachelor's program Global Sustainability Science.

The nature in the National Park Utrechtse Heuvelrug is under severe pressure from climate change, which amongst others poses significant challenges for water management in the area. Utrecht University and the Foundation Nationaal Park Utrechtse Heuvelrug (Stichting NPUH) have joined forces to face the challenge and deepen the existing collaboration by setting up the socio-ecological Research & Education Hub Utrechtse Heuvelrug. As part of this collaboration UU bachelor students set out to assess the water quality of the country estates in the national park. Robin Aanstoot, project coordinator of the Hub, spoke to Stefanie Lutz, course coordinator and environmental hydrologist from Utrecht University’s Copernicus Institute of Sustainable Development, and Ivor de Baat, project leader at Utrechts Landschap. During a walk on the Hoog Beek en Royen estate near Zeist, they talk about impact of increased weather extremes in the national park and the importance of the student-collected water quality measurements.

Climate change impacting the natural surroundings of the Utrechtse Heuvelrug

“Do you notice anything odd about these trees?” de Baat asks while passing a cluster of historic Scots pines. A withered canopy and peeling bark are clear signs of a forest under pressure. "Due to water stress in the area, these trees and their symbiotic network of fungi have become less resilient and are no longer able to withstand the invasive spruce bark beetle." This is a frequently heard story on the Utrechtse Heuvelrug, which due to its elevated position must deal with deep groundwater levels, especially during periods of drought. At the Hoog Beek en Royen country estate, the water level in the ponds has been dropping below a critical level during dry periods for some time. This desiccation has led to the weakening or loss of traditionally abundant trees and plants—mostly ancient specimens with great scenic and cultural-historical value. Fauna such as butterflies and insects that depend on these species or their humid environments are also under threat.

In a large-scale restoration project, water bodies across the Utrechtse Heuvelrug have been cleaned up and climate-proofed, with added benefits for biodiversity and the preservation of the area’s unique cultural and historical heritage. And this has resulted in some good news: “To our surprise, we were able to revive the spring that originally supplied seepage water to the ponds, and it now provides a home to frogs and other amphibians,” says de Baat. With good water quality essential, students from Utrecht University eagerly took on the task of assessing this in the various springs and ponds.

We see great enthusiasm among students when fieldwork extends beyond education alone and actually has an impact on practice

In the course Chemistry and the Environment first-year students of Global Sustainability Science learn to conduct fieldwork and collect and interpret data. The fact that their measurements not only have an educational purpose, but also provide useful information for water management is a unique opportunity for the students to make the connection between science and practice. “We see great enthusiasm among students when fieldwork extends beyond education alone and actually has an impact on practice,” says Lutz.

In the spring of 2023, around 150 students measured several critical indicators for water quality, including nitrates and nitrites, phosphate, the acidity and electrical conductivity of the water. This took place at various places across the Utrechtse Heuvelrug, including several locations in ​​the Zeister Bos restoration project. “A good balance of these indicators is essential for the flora and fauna found in and around the area’s water bodies. The detection of any imbalance is therefore a reason for further research and possible intervention by the landowners”, explains Lutz.

How will these water bodies be affected by more frequent extreme weather events due to climate change?

The students would like to return in the spring of 2024. “The restoration project is now almost complete,” says de Baat. “But we are very curious about how the natural environment will develop in the near future. How will these water bodies be affected by more frequent extreme weather events due to climate change? “By coming back and taking measurements every year we can keep track of how basic water quality indicators develop in the long term,” adds Lutz.

More opportunities for research

A unique restoration project like this offers even more opportunities for research. For a number of large buildings in the vicinity the rainwater that falls onto the roofs drains into the sewer. “There is great enthusiasm among the various owners to disconnect rainwater from the sewage system and connect it to the natural landscape. With more than 5000m³ of extra water becoming available annually, this would mean that water is retained in the area for longer,” says de Baat. "The question is to what extent such a large amount of rainwater can enter a pond safely, and what this would mean for the water quality and the flora and fauna in the pond." An excellent thesis research opportunity for an enthusiastic UU student!

It's clear that in the future we will see more students around the country estates of the Utrechtse Heuvelrug, contributing to a climate-proof landscape and the preservation of its unique ecosystem. When it is time to take their picture de Baat suddenly looks up: "Did you see that? A kingfisher, here on the estate! Wonderful isn’t it?".