'Deep Underground Stormwater Drainage Facilities' to be Prioritized for Installation at Gangnam Station, Gwanghwamun, and Dorimcheon in Seoul... Target Completion by 2027

Establishment of Implementation Plan for 'Deep Underground Stormwater Drainage Facility' Project... Disaster Prevention Performance Target Increased to a Maximum Frequency of 100 Years

Sinwol Rainwater Storage and Drainage Facility

[Asia Economy Reporter Lim Cheol-young] The Seoul Metropolitan Government is set to actively promote the ‘Deep Underground Rainwater Drainage Facility’ project at six flood-prone locations including Gangnam Station, Gwanghwamun, Dorimcheon, Sadang-dong in Dongjak-gu, Gangdong-gu, and Yongsan-gu.

On the 12th, Seoul announced that it has established an implementation plan for the ‘Deep Underground Rainwater Drainage Facility’ project to prepare for abnormal weather and create a safer Seoul against heavy rainfalls. The goal is to upgrade Seoul’s disaster prevention capacity from the current 30-year frequency (handling up to 95mm/h) to a 50- to 100-year frequency (handling up to 110mm/h).

The project will begin with three areas?Gangnam Station, Gwanghwamun, and Dorimcheon?where record-breaking heavy rains caused significant flooding damage in parts of Seoul last August. The plan is to minimize the project duration and complete it by 2027.

Gangnam Station is located in terrain more than 10 meters lower than its surroundings, causing rainwater to accumulate there during heavy downpours. The city plans to install a deep underground rainwater drainage facility along the 3.1 km stretch from Gangnam Station to the Han River, capable of handling heavy rain exceeding 110mm per hour. The Gwanghwamun area is where rainwater flowing down from nearby Inwangsan and Bugaksan Mountains concentrates. The city is considering installing a facility along the 3.2 km section from Hyoja-dong in Jongno-gu to Cheonggyecheon, capable of handling over 100mm of rain per hour.

Dorimcheon is narrower compared to other rivers, causing water levels to rise quickly during rain, and the steep slopes of nearby Gwanaksan Mountain cause rainwater to flow rapidly. The city plans to install a facility along the 5.2 km stretch from Sindaebang Station in Dongjak-gu to Yeouido, capable of handling over 100mm of rain per hour.

Dorimcheon Area Stormwater Drainage Facilities

The project budget is 350 billion KRW for the Gangnam Station area, 250 billion KRW for the Gwanghwamun area, and 300 billion KRW for the Dorimcheon area, totaling 900 billion KRW over five years from combined national and city funds. This ‘Deep Underground Rainwater Drainage Facility’ project revives a plan first initiated by then-Mayor Oh Se-hoon in 2011 following heavy rains in the Umyeonsan area, resuming it after 11 years. To ensure swift and consistent progress, Seoul has formed and is operating a dedicated organization called the ‘Deep Underground Project TF Team.’

Seoul expects that installing the ‘Deep Underground Rainwater Drainage Facility’ will minimize flood damage in the Gangnam Station, Gwanghwamun, and Dorimcheon areas. In fact, through the ‘Sinwol Rainwater Storage and Drainage Facility,’ the first of its kind installed domestically, no flood damage occurred in Sinwol-dong during the recent rainfall (about 60mm per hour). The city estimates that without this facility, 600 households would have been flooded.

As the first step of the project, feasibility studies and basic planning services for each site will begin next month to determine the specific scale of the facilities. The studies will be completed between the end of this year and the first half of next year, with installation completed by 2027. Additionally, the remaining three locations?Sadang-dong, Gangdong-gu, and Yongsan-gu?will be classified as phase two projects and promoted step-by-step.

Han Yoo-seok, Director of the Water Circulation Safety Bureau of Seoul, said, “The Deep Underground Rainwater Drainage Facility is one of the most effective measures to minimize large-scale flood and human damage in response to the climate crisis. We ask for the interest and support of citizens and experts from all fields. Seoul will also do its best to complete the project quickly for the safety of its citizens.”

This content was produced with the assistance of AI translation services.