1. Cheonggyecheon History and Restoration Project
1.1 Cheonggyecheon History
For 600 years, Cheonggyecheon had been the center of Seoul’s structural foundation, running from west to east in Hanyang (the name for Seoul when it was the capital of the Joseon Dynasty). The stream bisected the city’s south and north meridian.[1] For more detailed history, refer to ‘Feasibility & Basic Studies on the Social Impact of the CRP’ published in 2002~2005 by Seoul Metropolitan Government and Seoul Development Institute. And overall aspects of economic, social, cultural conditions also are contained in ‘Back to A Future Seoul: CRP’ book. Cheonggyecheon was once a living creek vital for everyday usage by the public, especially displaced refugees after the 1950-53 Korean War. It was slowly covered from 1958~1961 to solve pollution and flooding caused by the city’s rapid population increase.
The Cheonggye Elevated Expressway ran through the surrounding dense commercial district of the city and was an absolute necessity for post-Korean War development. It served as a vehicle for industrialization and modernization. The total length was 8.14km and the restored section is 5.84km long.
1.2 Push/Pull Factors of the CRP
The CRP was just the beginning of many more connected endeavors. An ecological space created from the restoration is undergoing phases of adjustment through ecological transformations and evolution. The CRP is influencing the redevelopment of the surrounding residential areas as well as commercial districts. The public is being encouraged to fully utilize the new waterside space and changed environment. The Seoul Metropolitan Government will provide administrational support for its smooth adaptation.
The main points of the arguments against the restoration project were that it would cause ① congestion and excessive through traffic; ② environmental degradation, air pollution, noise; ③ damage to historical heritage; ④ reduce competitiveness; and ⑤ stunt the growth potential of this northeastern district, etc. Most of these arguments, however, were outweighed by the enhancement of the natural environment and citizens’ quality of life, conservation of historical and cultural heritage, promotion of economic revival, a shift to more sustainable development, and the development of a future-oriented urban environment after the CRP.
Incidentally, this project did not end with the completion of the initial stream restoration, but is continuing into the next generation with more sections to be restored and revived. Seoul has found its identity through this work and will be able to restore its forgotten history. It will not only promote regional harmony but be reborn as an environment-friendly, international business hub.
2. Cheonggyecheon Restoration Process
2.1 Strategies
The restoration project extended almost 6km. The essence of the restoration program was “space creation” – a place where the city’s residents could enjoy the ‘liveliness of a friendly Seoul.’ Defined concepts of history (tradition), culture (modernity), and nature (future) were introduced to confer diversity onto the respective sections of restored areas.[2]Sections identified as History (tradition), Culture (modern), and Nature (future) were introduced to deal specifically with conferring diversity on the restored areas. History (tradition) were the key starting points over the first 2km segment. From 2km to 4km, the Culture (modern) theme dominated, and from 4km onward Nature (future) were the key ideas. Some devout ecologists have insisted that the restoration should have actually started from Cheonggyecheon’s original fountainhead. However, restoration refers to a number of different strategies and techniques applied to enhance the natural state and functioning of rivers and catchments.[3]Due to traffic problems and costs, inclusion of the original water source was moved to a long-term consideration. Instead, pipes and pumps were installed between Cheonggyecheon, its original source, and the Han River to provide a source of clean water.
2.2 Demolition of Structures
The demolition work started on July 1, 2003, and the elevated expressway was completely dismantled by October 5, 2003. The demolition of structures covering the stream began on August 18, 2003, and everything was completely dismantled by December 30, 2004. In order to reduce noise and dust during the work, the city used diamond wire saws and wheel saws. A total 680,000 tons of waste was generated during the demolition work. Of this 100% of the scrap iron and steel were recycled and 95% of the waste concrete and asphalt were recycled.
[Figure 1. Cheonggyecheon Stream]
2.3 Stream Design
The CRP was designed to create an urban natural stream to serve as a human- and environment-friendly space with sidewalks along its natural and constructed banks. Flood management was a top priority in designing the stream. To respond to increasing incidences of flooding and the frequent torrential showers during summer, the city built embankments that can withstand a 200-year-level extreme flood. Also, the minimum number of bridges were planned in order to transmit a maximum amount of water, and some covering road structures were preserved to further the amount of water flow during the monsoon season. Terraces and lower-level sidewalks were built along the upper and lower reaches of the stream for a water-friendly environment.
2.4 Water Supply and Management
Cheonggyecheon is an intermittent stream which requires additional water provision to maintain the water depth design guidelines of a maximum 40cm depth of water throughout the year. The water amount needed was estimated at more than 120,000 tons a day. The water is pumped from two sources: the Han River and an underground stream. The waters are discharged from four locations. The targeted level of water quality is Class-2, BOD 3mg/l.
[4]Class-1 has a high environmental adaptability for freshwater fish and Class-2 is for fish native to the Han River. Therefore the water of Cheonggyecheon is safe for recreational use, and children can play in the water with no worry of contamination from the habitat.
2.5 Roads and Bridges
Both sides of the stream are at least as wide as 13.5m to accommodate two-lane, one-way roads, sidewalks and loading/unloading spaces for business. The restored stream is accessible at 17 locations. Concerning traffic planning, left turns were kept to a minimum and U-turns are allowed only at three designated locations to protect the environment from car emissions. Five pedestrian bridges and 17 bridges for motorists were built across Cheonggyecheon.
2.6 Restoration of Historical Relics
The restoration of the old, buried Gwanggyo Bridge, one of the main relics, caused challenges because its original form had been severely damaged, and the location was at the center of an important traffic intersection.
[5]Gwanggyo Bridge was built in 1410 during the Joseon Dynasty. For more information on the history of other bridges, please visit "Culture Content offered by Korea Creative Content Agency"View It was very difficult to restore it in its original location because of ensuing traffic problems. Therefore, experts on cultural heritage decided the bridge should be moved upstream. Relocating another old stone bridge called Supyo Bridge to where it was originally placed would require a redesign of the stream due to the discrepancy between the length of the original bridge and the width of the restored stream. As for the Ogansu Bridge, it was considered to have only a slim chance at restoration in its original form, although its existence was confirmed. Restoration of all the old bridges was determined based on the results of a detailed index survey on relic restoration.
2.7 Construction Management
In order to reduce public inconveniences during construction, various measures were suggested: to set up a screen to separate commercial activities from the construction mess and to maintain functional loading/unloading spaces along Cheonggye Street. One drastic measure to respond to street parking shortages during the construction and the mounting complaints from Cheonggye street-vendors was to close Dongdaemun Soccer Stadium near Cheonggyecheon and turn its grounds into temporary parking lots and business space for the displaced street-vendors.
