Call for Measures Amid Spread of Anxiety
Highest Number in Metropolitan Areas Among 12 National Cases
Most Common Cause: Sewer Pipe Damage
City to Draft 5-Stage Safety Map by 2024
Insists on Non-disclosure Due to “Anxiety Generation”
Exploration of Railroad Construction Sites until May
Establishment of One-Stop System for Reporting to Processing
Last month, a sinkhole incident in Myeongil-dong, Gangdong-gu, Seoul, led to the death of one individual, shocking the public and causing fear among citizens due to successive similar incidents. Indeed, it was revealed that out of 12 sinkhole incidents nationwide by March of this year, five occurred in Seoul, indicating a need for countermeasures. Seoul is also taking steps to address the issue.
According to the Underground Safety Information System of the Ministry of Land, Infrastructure and Transport, 72 sinkhole incidents occurred in Seoul from January 2021 to March of this year. The incidents had risen to 22 in 2023 but dropped to 16 last year. However, there have been five incidents until March of this year, showing an increasing trend. Among the 12 sinkhole incidents nationwide this year, five occurred in Seoul, making it the highest among metropolitan areas.
In recent occurrences in Seoul, citizens’ anxiety is rising due to the repeated sinkhole incidents. Notably, a large sinkhole that spanned four lanes and was 20 meters deep occurred on the 24th of last month in Myeongil-dong, resulting in one fatality. On the same day, a ground crack measuring approximately 10 cm wide, though not categorized as a sinkhole, appeared near the redevelopment area in Samsung-dong, Gwanak-gu.
As the city and fire authorities are investigating the causes of the recent sinkholes, it was found that ‘sewer pipe damage’ was the leading cause of sinkhole incidents, accounting for 32 cases over the past five years in Seoul. Old sewer pipes leak, extracting soil around them, gradually enlarging underground voids. Poor backfilling (10 cases), faulty excavation work (10 cases), and water pipe damage (8 cases) followed.
Recurring annually, sinkhole incidents led the Seoul city government to draft a “ground subsidence safety map” last year, though it hasn’t been disclosed to the public. The map reportedly categorizes the entire city into five risk levels based on sinkhole hazards and classifies areas with aging water pipes or ongoing underground construction as risk zones.
Despite growing calls to disclose this after the Myeongil-dong incident, the city insists on non-disclosure claiming it could lead to unnecessary misunderstandings and anxiety. The map is explained as management material intended to enhance the efficiency of ground-penetrating radar (GPR) surveys, not as data indicating ground risk directly.
Despite these explanations, criticism persists. The Korean Confederation of Trade Unions and the Information Disclosure Center held a press conference in front of Seoul City Hall, stating, “There’s a widespread belief that the non-disclosure stems from property value concerns” and urged the release of the ground subsidence safety map for the safety and life of transportation workers.
Seoul held a countermeasure meeting attended by Mayor Oh Se-hoon and directors related to citizen safety. The city decided to conduct intensive GPR surveys of a 49.3 km section across five areas, including the Dongbuk Line, Sinansan Line, and the metropolitan express railway (GTX), plus surrounding roads by next month. The results, locations of cavities, and recovery details will be disclosed on ‘Seoul Safety Nuri.’
Additionally, the city is establishing a “rapid field inspection system” where signs of incidents can be processed from reporting to resolution in a one-stop manner. An advanced cooperative system with relevant agencies will be built, allowing rapid onsite response and prompt recovery and resolution upon reporting from citizens through any channel.
A city official stated, “We plan to create a map encompassing various factors and functions related to sinkholes,” adding that the decision to disclose the map will be internally reviewed considering social consensus.