The restoration of Cheonggyecheon was not a simple matter of lifting a cover and allowing an ancient watercourse to flow naturally again. It was a large-scale reconfiguration of central Seoul: the aging elevated road was demolished, covered structures were opened, and a new stream channel, walking paths, bridges, and landscaping were built. Construction began in July 2003, and the corridor opened to the public in October 2005.
The stream is not sustained only by natural upstream flow
Urbanization eliminated many old tributaries and altered groundwater conditions. Today's Cheonggyecheon therefore relies on water supplied from outside sources, including the Han River and groundwater, to maintain its flow. It is more accurate to understand it as a technologically maintained urban stream than as a natural river returned completely to its original state. Energy use and maintenance costs are part of the restoration story.
Removing the elevated road changed walking and the downtown landscape
Water and pedestrian paths replaced a space dominated by vehicles, altering the thermal environment, urban scenery, and how residents spend leisure time downtown. Traffic was also redistributed to surrounding streets, and access to the water remains restricted in some sections. The project did not eliminate cars from central Seoul; it was a policy choice that reordered priorities for movement.
Historical recovery, ecological recovery, and commercial recovery are different questions
The treatment of Gwangtonggyo, Supyogyo, and surviving stonework was disputed during construction. Nearby merchants faced disruption, rent pressure, and changes in business composition, and some relocated. The creation of water and greenery does not by itself prove that the historical form, ecosystem, and local economy were all restored. Cheonggyecheon is a place where substantial achievements and unfinished problems must be considered together.