Cheonggyecheon was once a landmark stream steeped in history. However, towards the middle of the 20th century, it became a victim of urbanization. To resolve this, the river was covered with concrete and turned into a 6 km roadway around the late 1950s. By 1971, it had a 5.8 km, 6-lane elevated highway to accommodate the increasing vehicular traffic in the capital.

For a while, this infrastructure served its purpose. However, by 2000, the highway reached its point of obsolescence. The structure lacked structural integrity, as carbon monoxide, methane and other gases accumulating at the sewer and drain level below the road were noted to have led to the foundation's corrosion.

Engineers from the Korean Society of Civil Engineering estimated that it would cost $95 million to fix. In addition, large volume of traffic also posed health concerns for the surrounding communities.

Then Mayor Myung-Bak Lee proposed a paradigm shift in urban management: a Seoul that is for people and not for cars. The first step was to dismantle the old road and elevated highway, and revitalize the historic stream.

During the demolition, they used diamond wire saws and wheel saws to minimize noise and dust. They generated 872,400 tons of waste (concrete and asphalt) and 96 percent of this was re-used, while all of the scrap iron was recycled.

For constant water supply, they fed in and treated water from the Han River and underground water from subway stations. They also future-proofed the waterfront by constructing embankments that can endure the worst kind of flood (noted to occur every 200 years).

For an effective urban paradigm shift, the city government engaged stakeholders through thorough consultations. They explained the value behind restoring the Cheonggyecheon stream over investing in an expressway.

In addition, the city government also integrated bus and rail for more seamless travel and discouraged driving private vehicles in the city center.

Removing the expressway and the many vehicles that traverse it improved the city's air quality and noise levels. The former roadway became a green belt combining three zones: history, urban and culture, and nature. The new waterfront with its teeming biodiversity enhanced this further.

The resulting serene stretch additionally contributed to reducing the urban heat island effect in Seoul. It also cemented Cheonggyecheon as a place for high quality living.

Photo by Sandi Benedicta on Unsplash