Re-Naturalizing a Stream: Seoul's Cheonggyecheon Restoration Project

One of the most memorable experiences from my trip to Seoul last summer was walking along the banks of Cheonggyecheon in the early evening. It was a thriving urban space with many activities — people resting with their feet dipped in the cool stream water, children frolicking in the shallow water.

But Cheonggyecheon wasn’t always like this — just over 2 decades ago, it was sealed by a concrete cover and an expressway bridge. How did Cheonggyecheon transform? How did this impact Seoul? Here are some things I discovered.

A brief history

Cheonggyecheon runs west to east through central Seoul before feeding into the Han River. It served a critical role as the city's water source and drainage system. However, Cheonggyecheon became severely polluted after the Korean War due to direct waste discharge from the shanty towns alongside the river.

Beginning in 1958, the government started covering the stream with concrete. Finally, in 1976, a highway was constructed directly above the stream in response to growing urban pressures.

Restoration

As the industrialization phase of South Korea’s rapid development passed, urban planners began to re-evaluate their strategies. Thus, in 2003, the Seoul government began restoring the stream to create a linear park and revitalize local ecology.  

Cheonggyecheon was re-naturalized — planners introduced pedestrian-friendly features while also crafting unique river ecosystems for plants and animals (Carrasco)

After demolishing the highway bridges and concrete coverings, planners diverted water from the Han River and underground tunnels to ensure a constant year-round flow that would keep the depth of the stream at around 40 cm. Vegetation profiles were also constructed along the banks, with designers seeking inspiration from streams in other parts of Korea. Pedestrian walkways and infrastructure were also built to develop Cheonggyecheon into a public green space that encourages civic engagement (Carrasco).

Impacts

While some have criticized Cheonggyecheon’s restoration as an example of forced “re-naturalization,” the project has brought many socio-environmental benefits to Seoul residents. For instance, it mitigates the heat island effect in central Seoul by reducing temperatures by 3 to 6 degrees Celsius while creating a corridor for urban ventilation. Land prices have also risen in riparian neighborhoods, with a boom in businesses due to the favorable environment Cheonggyecheon has fostered (Robinson and Hopton).

Cheonggyecheon before (left) and after (right) restoration (WWF) 

Overall, Cheonggyecheon is a fascinating case study of urban transformation that arises from new design doctrines. In downtown Shanghai, many streets lie above former rivers — perhaps planners can take a lesson from Seoul in restoring natural landscapes in urban environments.

Bibliography

Carrasco, Moises. ‘Re-Naturalization of Urban Waterways: The Case Study of Cheonggye Stream in Seoul, South Korea’. ArchDaily, 12 Sept. 2024, https://www.archdaily.com/1020945/re-naturalization-of-urban-waterways-the-case-study-of-cheonggye-stream-in-seoul-south-korea.

Robinson, Alexander, and Myvonwynn Hopton. “Cheonggyecheon Stream Restoration Project.” Landscape Performance Series. Landscape Architecture Foundation, 2011. https://doi.org/10.31353/cs0140

Thomas, Aaron. ‘Seoul Cheonggyecheon River’. WWF, https://wwf.panda.org/wwf_news/?204454/Seoul-Cheonggyecheon-river. Accessed 20 Jan. 2025.