Opening Rivers – Urban DesignUrban Design

Historically, rivers and streams played a crucial role in the development of cities. They served as sources of water, routes for trade, and even natural barriers for defense. However, as urbanization took hold, many of these rivers were buried in culverts or underground channels, often to make room for development or to mitigate flooding risks. (Varley, 2024) This practice, particularly during the Industrial Revolution and the early 20th century, led to the loss of many open waterways that once shaped urban landscapes. In recent years, however, there has been a growing movement to “uncover” or “daylight” these rivers, aiming to restore their ecological, aesthetic, and social value to modern cities.

The Reasons Behind River Covering

1. Flood Control: Rivers in urban areas were often covered to prevent flooding, especially in cities where flood management systems were underdeveloped or overwhelmed by rapid urban growth. Encasing rivers in underground pipes or tunnels (culverts) allowed cities to continue expanding without the risk of seasonal flooding by these rivers (Varley, 2024).
2. Land Availability: As cities grew, there was an increasing demand for space for infrastructure, housing, and businesses. Rivers often occupied valuable land that could otherwise be used for these purposes. Covering the rivers made it possible to build roads, buildings, and other structures on top of them (Varley, 2024).
3. Sanitation: In the past, rivers were used as waste disposal systems, and their open exposure led to unpleasant odors and unsanitary conditions. Covering them helped mitigate these public health concerns, especially in rapidly industrializing cities.
4. Functionality: Over time, rivers were seen as troubles, their natural beauty and function overshadowed by the need for more functional spaces in urban centers. As a result, urban planners turned to engineering solutions that buried rivers beneath the city, hiding them from public view.

Activism and the Call for River Reopening

As environmental awareness grew, and with it, calls for the reopening of covered rivers. Activists, urban designers, and community groups have been at the forefront of efforts to “daylight” rivers, acknowledging the many benefits of bringing them back to the surface.

1. Ecological Benefits: Daylighting rivers can improve the health of aquatic ecosystems, providing habitats for fish, birds, and other wildlife. Urban rivers also serve as natural water filtration systems, helping to purify rainwater and reduce pollution in surrounding areas. In addition, rivers provide valuable flood mitigation by offering natural water storage and slow-release systems, thus reducing the risk of urban flooding (Naturally Resilient Communities, no date).
2. Cultural and Social Value: Rivers are part of the cultural heritage of many cities. They offer recreational opportunities such as walking, cycling, and boating, and contribute to a city’s aesthetic value. Open rivers help create vibrant public spaces, fostering community interaction and improving quality of life for urban dwellers (Naturally Resilient Communities, no date).
3. Climate Change: With the increasing frequency of extreme weather events due to climate change, daylighting rivers can play an essential role in managing storm water and preventing flooding. Open rivers allow for more natural water management systems, helping cities become more resilient to climate change (Naturally Resilient Communities, no date).

Challenges in Reopening Covered Rivers

1. Cost: Uncovering a river often involves significant financial investment. This includes the cost of redesigning infrastructure, relocating existing buildings or roads, and ensuring the river’s ecological sustainability. These costs can be prohibitive for many municipalities, especially those facing budget constraints (Naturally Resilient Communities, no date).
2. Space Limitations: In densely populated urban areas, space is often limited. Uncovering a river may require the removal of structures and infrastructure, which could displace communities or businesses. The process might also require significant urban redesigns, which can face resistance from local stakeholders (Naturally Resilient Communities, no date).
3. Complex Engineering: Reopening a river is not simply a matter of removing a cover. It requires careful engineering to ensure that the watercourse is managed effectively. This includes mitigating flood risks, managing water flow, and ensuring that the river is integrated into the city’s existing drainage and water management systems (Naturally Resilient Communities, no date).

Example of River Reopening Projects

1. The Cheonggyecheon Stream in Seoul, South Korea: One of the most famous river reopening projects, the Cheonggyecheon was once covered by a highway. In 2003, the city of Seoul undertook a massive project to remove the highway and restore the stream, creating a 5.8-kilometer-long green space that revitalized the surrounding areas. The project improved local air quality, provided a habitat for wildlife, and became a popular recreational space for residents and tourists alike (Cheonggyecheon Restoration Project, 2024).

Conclusion

The movement to reopen covered rivers is a critical step towards creating more sustainable, livable cities. While the challenges of space, cost, and engineering are significant, the long-term benefits—ranging from ecological restoration to improved quality of life—make it a worthwhile investment. By learning from successful case studies around the world, cities can design more integrated, nature-based solutions to tackle the challenges of urban flooding and climate change, while simultaneously revitalizing their urban landscapes and reconnecting citizens with their natural heritage.

References:

• Varley, D. (2024), ‘Introduction to Blue Green Newcastle,’ Lecture Notes. Newcastle University.
• Naturally Resilient Communities (no date) Daylighting Rivers and Streams. Available at: https://nrcsolutions.org/daylighting-rivers/ (Accessed: 06/11/2024).
• Morton, D. (2022) The great storm of 2012: Recalling ‘Thunder Thursday’ in 20 photographs 10 years on. Available at: https://www.chroniclelive.co.uk/news/history/gallery/great-storm-2012-recalling-thunder-24333097 (Accessed: 07/11/2024).
• Kim, J. (2023) From Concrete to Oasis: The Cheonggyecheon and the Future of Urban Stream Restoration. Available at: https://greencityblog.com/cheonggyecheon-restoration-project/ (Accessed: 08/11/2024).
• Purucker, E. (2006) TGrenzenlose Landesgartenschau 2006 in Marktredwitz: Wasserspielplatz am wieder freigelegten Lohbach.. Available at: https://www.fichtelgebirge-oberfranken.de/marktredwitz/wasserspielplatz2.htm (Accessed: 08/11/2024).