Cheonggyecheon: The Flow of Progress


Restoring a six-kilometre stream that has been covered by an expressway for over fifty years is not an easy task. The job is even more difficult when the stream happens to meander through one of the world’s largest and most densely populated cities. The Cheonggyecheon, or the Cheonggye Stream restoration project is without question the most ambitious urban renewal scheme to have ever been undertaken in the history of Seoul.

The aims of the Cheonggyecheon restoration project, completed in 2005, were first, to rectify a severe public safety problem caused by an expressway that threatened to collapse at any moment; second, to address Seoul’s deteriorating environmental conditions by creating an environmentally friendly place in the centre of the city; third, to pay tribute the history of the 600 year old Korean capital; and fourth, to spur redevelopment in the surrounding neighbourhoods, which at that time lagged behind other neighbourhoods in the central city.

To fully appreciate the significance of the Cheonggyecheon project to the Korean people it is necessary to know a little bit about Korean history, particularly as it relates to Seoul. The Choson Dynasty, led by Emperor Taiju, chose the land on the banks of the Cheonggyecheon near its intersection with the mighty Han River as Korea’s capital in 1392. Monk Muhak, on behalf of Taiju, selected the site after an extensive two-year search for a location that satisfied the principles of feng shui. According to Muhak, the site possessed powerful Earth energy that was enhanced by a prominent mountain directly to the north, another to the south and two other mountains situated to the east and west of the site.

It was along this stream that the Choson Dynasty temple was built and the capital city planned. The Choson Dynasty ruled Korea up until the end of the nineteenth century and Seoul had remained the country’s relatively quaint capital city for five centuries. The Cheonggyecheon, unpredictable and prone to flooding, was successfully managed by government engineers throughout the centuries of the Choson Dynasty. The fall of the Choson Dynasty and the creeping influence of the Japanese marked the beginning of a difficult time for the stream, and indeed the country as a whole. It was also the start of a disastrous era of urban planning in Seoul.

The Japanese began exerting their power in Korea in 1876 with the signing of the Treaty of Ganghwa, which essentially opened up Korea to Japanese trade. This was followed by the Japanese initiated assassination of Empress Myeongseong in 1895 creating the necessary conditions for the Japanese to begin infiltrating the Korean government (credit britton). By 1910, Japanese Imperialist forces had assumed control of the Korean peninsula. The Japanese maintained their occupation of Korea until the end of the Second World War (WWII). During their occupation, Korea suffered near cultural annihilation at the hands of the Japanese who embarked on an elaborate scheme to systematically erase Korean identity. Korean people were forbidden to speak their language and many temples and monuments of historic significance were deliberately destroyed. Following the victory of the allied forces and the subsequent end of WWII, Korea once again regained control of her territory but quickly descended into a brutal civil war between the communists in the north and the democratic forces of the south.

The civil war was devastating to the country’s economy. Korean living standards, once the highest in East Asia, became abysmal. Seoul suffered the brunt of the war, changing hands four times. During the war, an astonishing 47% of the housing stock in the city was destroyed leaving millions homeless and much of the capital city in ruin.


The Cheonggyecheon acted as a sort of meeting point for the displaced and dispossessed people of Korea as thousands fled to the safety of the South while others retreated to the North. A shantytown developed on either side of the Cheonggyecheon where beautiful temples and eloquent government buildings once stood. The stream was the only source of fresh water for the poor residents of the area and because the slum lacked adequate infrastructure, it also became a dumping ground for raw sewage. Due in part to Seoul’s extreme climate and also the destruction of the Choson era engineering solutions, the polluted stream would virtually dry up for much of the year while overflowing its banks during the August monsoons.

Despite a truce in fighting (which remains in effect today), conditions continued to worsen in the Cheonggyecheon and its surrounding neighbourhoods in central Seoul. Imminent threat of a disease epidemic in 1958 forced the newly minted government to finally act. The stream was covered with concrete to reduce the spread of disease, however the initiative did nothing to address the horrendous environmental state of the stream and covering it essentially turned the stream into a sewer.

Subsequent government administrations completed an inner city expressway overtop of the once celebrated stream. The Sang-il expressway was completed in 1967 and quickly became an important east-west access route to and from downtown Seoul.

Fast-forward 30 years from the construction of the expressway and one is transported to a very different Korea. Samsung Electronics has surpassed its Japanese rival Sony on world markets while Korean made Hyundai and Kia automobiles are bought and sold in almost every country around the world. By the end of the twentieth century Korea has the eleventh largest economy on Earth and the second richest populous in Asia. On its final day of existence in 2003 the Sang-il Expressway carried 170 000 cars a day, yet another sign of the immense economic progress Korea had experienced since the end of war. For the city’s forward thinking mayor, Lee Myung Bak, it was also an indication that Seoul was a city choking on its own success.

Mayor Lee Myung Bak ordered the expressway closed on July 1, 2003. The Seoul Metropolitan Government, in cooperation with various engineering, urban planning, construction and archeological specialists, as well as an active citizen’s group, were about to undertake an immense, two-year project. The project would consist of tearing down the expressway, removing the concrete, exposing and cleaning the Cheonggyecheon as well as salvaging whatever historic relics that could be found in the process. The Mayor’s ambitious plan was not only meant to improve the despicable environmental conditions of his enormous city or even to revitalize relatively poor areas of his city, but Lee Myung Bak was, in a greater sense, hoping to restore the dignity of the Korean people and celebrate an important era of a culture that was almost erased from our world not so long ago.

The initial stage of the project involved three major steps. Firstly, the existing expressway had to be cut up and transported to a more people friendly location where it was to be converted back to its base parts. Secondly the concrete pillars had to be cut away piece by piece and removed from the site. Thirdly, the ground level surface had to be ripped off to reveal the stream below.


The mayor ensured that the demolition work would be done without causing excessive noise or dust pollution, nor would there be any road closures as a result of the work. Furthermore, prior to the commencement of the project it was determined that 95% of all asphalt and concrete removed from the site, and 100% of the iron and steal were to be recycled and used for other construction projects that the Seoul Metropolitan Government was undertaking. In total 680 000 tonnes of debris was removed from the site. In addition to the highway structure itself, the demolition crew removed lampposts, crash rails, drain pipes, electrical conduits and expansion joints. Some pieces of the highway that were trucked away weighed as much as 300 tonnes and were up to 70 metres in length.

As the demolition work was being conducted, archeologists began the difficult task of sifting through the rubble in search of relevant artifacts. Archeologist Ji Yeoun Hong recalls the terrible stress of working on the construction timetable, in what was close to raw sewage, with the added distraction of “huge concrete masses being lifted away by massive machines, sometimes directly overhead.” The main objective of the archeologists was to find remaining components of the famed Gwangtonggyo Bridge. The Gwangtonggyo Bridge was the largest bridge crossing the Cheonggyecheon during the Choson Dynasty Era. Despite the unfavourable conditions of the dig, the archeologists were able to find many of the original stones of the bridge. To the surprise of the archeologists, it was revealed that some of the original stones used to construct the bridge were, at some point in time, plundered from the grave of a disgraced queen. The archeologists also uncovered 250 metres of the old embankment walls that were constructed by the Choson engineers. Among other items uncovered were hairpins, bronze mirrors, and shoes. It is believed that these items were offerings to ‘the gods’ from local peasant women.

Another difficult component of the Cheonggyecheon project was ensuring that water would remain clean and flowing throughout the year. Hydrologists determined that in order for the stream to run smoothly, constantly, and pathogen free, the water would have to flow at a speed of one kilometre per hour. To achieve such a flow rate it was necessary for engineers to divert water from the nearby Han River and carry the water through specially constructed pipes 12 kilometres to the head of the newly revealed stream. A redundant water works facility was built to filter the water diverted from the river so that by the time the water was released into the stream it was clean, clear and safe for contact with human toes and feet. Stepping-stones were laid at 28 different locations along the stream to further filter the water and control its flow speed.

In order to mitigate the threat of annual flooding during Seoul’s late summer monsoon season, engineers constructed flood control tunnels beyond the embankment walls. In times of heavy rain and high stream levels, doors would open so that that excess water, often containing pathogens, would be carried away safely to the much larger Han River.

To allow citizens, tourists and vehicles to conveniently access neighbourhoods on both sides of the stream, the Seoul Metropolitan Government constructed 22 bridges, some based on designs submitted by the public. The crowning piece of the Cheonggyecheon project, however, would be the reconstruction of the 12 metre long, 16 metre wide Gwangtonggyo Bridge. The bridge would be rebuilt, to the appeasement of the project’s archeological team, much like the first, complete with many of its original stones. An artificial waterfall, fountains, and sculptures were also constructed to enhance the aesthetic impacts of the stream project.


The public was invited to the grand opening of the Cheonggyecheon in July of 2003. They were encouraged to walk along the pedestrian paths running parallel with the stream and plant trees. People were also able to read commemorative plaques outlining the long history of the Cheonggyecheon, and to learn more about the six hundred year history of Korea’s capital city.

The stream has been open for about three and a half years and there have been some noticeable environmental and economic benefits associated with its reincarnation. According to local residents, office workers, and shop owners, air quality in the neighbourhoods immediately adjacent to the stream has improved substantially. Analysis of ground level temperatures in the vicinity of the stream indicates that the stream has reduced temperatures by approximately three and a half degrees Celsius. Studies also show that wind speeds along this corridor are on average 50% higher now than they were prior to the uncovering of the stream. In effect, the Cheonggyecheon acts as a natural air conditioner for this area of Seoul. Another surprising environmental benefit of the project has been the emergence of a small population of Chinese minnows in the stream.

Despite the above-mentioned environmental benefits of the project, the Cheonggycheon is not without its critics. Some South Korean environmentalist groups have criticized the high cost of the project (approximately 900 billion won or about US$1 billion). They claim the environmental benefits to be minimal given the amount of money spent, especially when factoring in the 800 million won (US$900 000) spent annually on electricity to pump over 100 000 tonnes of water a day from the Han River. Many skeptics in Korea see the Cheonggyecheon as a purely symbolic project that was undertaken to benefit the legacy of a mayor rather than the environment of a city.

Whether you believe the project makes financial or ecological sense, it must be said that the Seoul Metropolitan’s goals for the Cheonggyecheon have been achieved. The once dilapidated and dangerous highway is a thing of the past. Moreover, Seoul residents now have a soothing, semi-natural space to enjoy well within the city’s central core. Also, locals and tourists alike are able to learn about an important era of Korean history by reading the plaques commemorating the stream and by visualizing what life may have been like for people living there centuries ago. Finally, the surrounding neighbourhoods that were economically depressed now seem to be coming alive as modern department stores and multi-level western style cafes are rapidly replacing many of the structures reminiscent of the shantytowns of yesteryear.

The Cheonggyecheon project makes me think of the Red Hill Valley in my home city of Hamilton, Ontario, Canada. Unfortunately, the not so progressive establishment of my fair city has decided to use public funds to remove thousands of trees in a lush valley setting, and channelize, and essentially cover, large sections of the Red Hill Creek.

Like the Cheonggyecheon, the Red Hill Creek has a storied past. The Red Hill Creek, and indeed the whole valley system, was for thousands of years, the lifeblood of a vibrant aboriginal hunting and gathering community. More recently the Red Hill Valley was enjoyed by me, my childhood friends, and thousands of other Hamiltonians, not to mention eighteen species of fish and countless other mammals, reptiles, amphibians, birds, and butterflies that, until recently, thrived in their natural setting.

The decision has been made and the work has commenced. In no time, North America’s largest contiguous natural corridor within an urban area will be replaced by, you guessed it, and expressway.

I wonder what Emperor Taiju would think?

This entry was written by David Maloney , posted on Thursday February 08 2007at 01:02 am , filed under Asia Pacific, Environment, Public Space and tagged , , , , , . Bookmark the permalink . Post a comment below or leave a trackback: Trackback URL.

4 Responses to “Cheonggyecheon: The Flow of Progress”

  • I forgot to reply to this when you first posted it, but I first read about Cheonggyecheon a year or two ago. It’s absolutely remarkable. I’m sure there are other examples of hidden streams being uncovered, but this is probably the only case in which a highway covering a stream has been so completely removed and replaced with such a gorgeous civic space. I can only imagine how pleasant it must be to wander through the city along the water.

    Much of Montreal is crisscrossed by old rivers and streams that have been built over. A large part of the city’s southwest used to be a lake. I suppose the old streams must still run underground… I wonder if it would be possible to unearth a section of one.

  • Steinholtz says:

    Actually the work completed in Hamilton on Red Hill Creek represents the longest creek restoration project in North America, in an urban setting. Absolutely no portion of the creek has been covered over. In 2005, for the first time in a quarter century, salmon were observed swimming unaided to just below the Niagara Escarpment. The Red Hill Valley Project in Hamilton Ontario Canada is one which it’s citizens can be very proud, as defining the standard in sustainable infrastucture development. Delegations fron all over the world have been visiting Hamilton to view this marvel of environmental/hard engineering integration.

  • Liane Lafer Schevz says:

    Dear Sir
    The Municipality of São Paulo, Brazil, trough the Urban Planning Secretariat is preparing a publication concern to revitalization projects for a Elevated Central Artery in the city downton. For that purpose we decided to enlighten the book with some international experiences like the Cheonggyecheon project . We are interested in some pictures that shows the region, before and after the intervention. We need to know how to obtain these pictures in a high resolution image and how much it costs? My name is Liane. Thank you

  • Liane, I apologise for the late reply. If you still need the images, you can select the ones you want and I can send the original electronic files to you free of charge, as long as you give me credit for the photos! Anyway, email me and we can arrange things. Thanks for your interest in the Cheonggyecheon project and in my photos.