Honor Award

ChonGae Canal Source Point Park: Sunken Stone Garden,
Seoul, Korea

Mikyoung Kim Design, Brookline, MA
client: Seoul Metropolitan Government

Project Statement

This project is located within the two urban superblocks of the Central Business District in Seoul, the main source point of the ChonGae Canal. The design is comprised of individual stone sculptures, symbolizing the future unification of the nine provinces of North and South Korea, and celebrating the source point of cleansed surficial and sub grade runoff from the city. The stones, from provincial quarries, frame the urban plaza while bringing public access directly to the water’s edge. The canal design accommodates seasonal flooding, its appearance changing as stones are submerged and reappear.

Project Narrative

The ChonGae Canal Project is a part of the ambitious waterway redevelopment effort by the city of Seoul to restore this highly polluted and covered waterway with the demolition of nearly four miles of at grade and elevated highway infrastructure that divided the city. The submitting landscape architect designed two superblocks within this corridor. The other blocks were designed by local landscape architects and the Army Corp of Engineers. The outcome is the creation of a pedestrian focused corridor from this former vehicular access way that brings people to this historic ChonGae waterway.

The ChonGae Canal Project is located at the important source point of this seven-mile green corridor that begins in the central business and commercial district of the city. The charge of the international design competition for this project was to create a symbolic representation of the future reunification of North and South Korea within this two block urban park. The ChonGae Canal Project proposal defined the nine provinces through the use of local materials and nine sources of water. Regional stone quarried from each of the nine areas and nine source points of water and fiber-optic light highlight this collaborative effort of reunification and restoration of the waterway. The individual stones act to frame the nine source points of the canal and represent the unified effort in the transformation of this urban center.

The design was guided by the water levels from hour to hour and season to season, while addressing the catastrophic flooding that occurs during intense storms in the Monsoon season. The unique sloped and stepped stone elements allow for a reading of the various levels of water while encouraging direct public engagement with the river. The restoration of this area is the first step in a major redevelopment effort of this seven-mile corridor and current ambitious architectural redevelopment projects that frame this natural drainage basin to the city.

In addition to the environmental restoration effort, this urban open space has become a central gathering place for the city which is in dire need of more public landscapes. The Class II water quality level has allowed for families to come and reengage with this historical river. During specialized events such as the traditional New Year’s festivals, political rallies, fashion shows and rock concerts both the plaza and the Water Source area get redefined in inventive ways. Since the ribbon cutting ceremony in October 2005 on the main plaza, nearly 10 million visitors and residents have visited the river. Recently, coins that were tossed in the canal by visitors were collected from the basin and thousands of dollars were donated to local charities.

History of Chongae River
Historically, the ChonGae Canal was a naturally formed river collecting drainage from the surrounding mountains. The stream was one of the reasons Seoul was selected as the capitol of Korea in 1394. The strategic location of water and the surrounding protective mountains on each side of the city made it an ideal location for Korea’s political, cultural, and social center. For over four hundred and fifty years, wastewater and raw sewage drained directly in the ChonGae River. With intense population increases in Seoul, the river became a source of serious sanitation and health concerns and a symbol of poverty for the city. From 1920 to 1937, during the Japanese occupation of Korea, this severely degraded and contaminated river was covered and the makeshift shantytowns around it were demolished. In the mid 1960’s an elevated highway was built over the river, further obscuring its presence, and dividing the city.

Revitalization of the Historic Chongae River
The vision to revitalize this historically important natural feature of the city began with this Ideas Competition for the two urban superblocks at the source point of the entire waterway redevelopment. The Chongae Canal Project is a piece within with seven-mile stretch at the source point of the uncovered waterway. We worked closely with the Seoul Army Corps of Engineers to mitigate the contaminated condition, both addressing the trapped underground gases once the river was uncovered and the challenges of working with the new retention and purification infrastructure that manages peak demand during flooding conditions. Surficial and subgrade storm water runoff is harvested and enters the ChonGae waterway while sewage is diverted into a separate purification system.

At the source, the design accommodates up to a 100-year storm which mitigates serious flooding issues that inundate the city during Monsoon season. Surficial runoff and 22,000 tons of underground water/day from subway stations also drain into the ChonGae River. Up to 75,000 tons of water per day is pumped from the Han River during the dry season to help the conveyance of water from the central wastewater treatment plant and moves the water through the city back into the Han River.

The City of Seoul won the World Technology Award for its restoration efforts of the waterway from the World Technology Network in San Francisco in 2005. The project as a whole has been effective in decreasing air pollution by allowing greater wind passage through this area and has also decreased the heat island phenomenon that existed in this area prior to the renovation of the river. The ecosystem of the Cheonggyecheon Stream is also being restored encouraging 213 new species of birds and fish and other organisms in the area. The purification system has brought the water quality level to Class II allowing for the public to safely reengage the water.

This Sunken Stone Garden is the source point of a larger 5.8  km long public recreation space in Seoul, Korea. The remaining portion of the ChonGae Canal Restoration project and the upper public plaza were designed by others and not part of the ASLA award.