by Delia Baumann, Kaspar Aeneas Lengacher, Maximilian Lengenfelder
In the mid-19th century, around 160 kilometres of open streams shaped the landscape of Zurich. By the late 20th century, rapid urban expansion had reduced this network to roughly 60 kilometres. Streams were increasingly channelled underground, often misused as sewage drains, to make room for buildings and infrastructure—at the cost of ecological function and spatial quality.
Since the 1980s, however, a societal and planning paradigm shift has taken place. Urban streams are now recognised as valuable ecological and social resources. Through renaturation projects, previously buried watercourses are being brought back to the surface in a process known as daylighting. This shift is also reflected in legislation: under the federal Water Protection Act, streams may no longer be covered except under specific circumstances such as flood protection or essential infrastructure crossings.
Our blog examines where additional daylighting could still be possible within Zurich and what benefits it might bring. Open streams contribute to biodiversity, improve microclimates and enhance human wellbeing. Daytime air temperatures can drop by up to 1.5 °C in well-designed, vegetated stream corridors, while access to water and green space has been shown to reduce stress and improve quality of life.
Using literature research and qualitative GIS analysis, we identified five stream segments with daylighting potential. We further discuss the feasibility of daylighting the specified streams, which are mostly located at the interface between settlement and agricultural land. These areas have fewer structural barriers but more complex land-use trade-offs.
Many questions remain: how can competing land uses be balanced, and where should future projects be prioritised? How can competing land uses be balanced, and where should future projects be prioritised? For answers to these questions, take a look at the blog post we produced in the context of the Geography. Matters. module at the Department of Geography in the fall semester of 2025.
https://zurichhiddenwaters.blogspot.com/
About GEO410
This blog post is part of the outcome of an interdisciplinary Master’s-level course in Geography: GEO410 Geography. Matters. The course aims to bring together diverse geographic research perspectives to engage with some of the most pressing societal and environmental challenges of our time. As the only compulsory module of the Geography MSc program, the course encourages students to think across sub-disciplines of geography and to explore how geographic research can meaningfully contribute to debates around sustainability, justice, and environmental change.
Beyond conducting interdisciplinary research as a team, a central aim of the course was to experiment with creative and accessible forms of science communication. Rather than producing a purely academic output, students translated their research insights into blogposts, intended for a wider, non-specialist audience. The contributions thus showcase not only rigorous scientific work by highly motivated students, but also the importance of communicating research beyond the university and engaging broader publics in conversations about geography, sustainability and the future of our shared environments.
The students in the course GEO410 were supervised by Andreas Vieli, Christian Berndt and Sofia van Moorsel as lecturers and by Nikolas Klaudy as teaching assistant.
Beitragsbild: Open stream in Zurich with well-developed stream ecosystem. Image: Stadt Zurich panotour