Real Parasite of Reality: Urging a Plan to Install Flood Barriers for Genuine Low-Income Basement Dwellers.

Recent surveys have revealed that over 80% of the basement dwellings in Seoul, particularly those built before 1995, suffer from severe aging. This concentration of aged basement dwellings can be attributed to the construction boom of such dwellings in the late 1980s and early 1990s. Among the 25 administrative districts in Seoul, Gangnam-gu has the highest number of basement dwellings, but the older and more deteriorated ones are predominantly found in the northern regions.

 

Addressing the basement dwelling issue in Seoul is a crucial challenge for ensuring the safety and stability of residential environments.

 

In 2023, during the Seoul Research Institute Policy Forum, Senior Researcher Seo Sang-yeong presented the topic of "Policy Approaches to Mitigate Flooding Risks in Seoul's Underground Spaces," unveiling these research findings. According to building records as of December 31, 2021, Seoul has an estimated 202,741 basement dwellings, accounting for approximately 5% of households (4,046,799 households) and 6.6% of housing units (3,068,494 housing units).

 

Examining the construction approval dates, it was confirmed that over 80% of basement dwellings were built before 1995. This phenomenon was a consequence of policies aimed at increasing urban housing stock, which led to a surge in the construction of multi-unit dwellings, including basement dwellings, from the late 1980s to the early 1990s.

 

While Gangnam-gu has the highest number of basement dwellings among the 25 administrative districts, the aging problem is relatively less pronounced there. On the other hand, areas with a high concentration of basement dwellings built before 1990 are mostly situated in the northern regions.

 

Based on flooding history, basement dwellings located in areas that experienced flooding at least once make up 9.7% of the total, while those in areas that flooded twice or more account for 1.3%. Among these, the districts with the highest number of basement dwellings in areas that flooded twice or more are Dongjak-gu (621 units, 24.4%), Yangcheon-gu (427 units, 16.8%), Gangnam-gu (420 units, 16.5%), Gangseo-gu (380 units, 14.9%), and Seocho-gu (264 units, 10.4%).

 

Assessing basement dwelling flooding risks based on expected flooding depth, there are 15,102 basement dwellings (7.4%) in areas designated as flood-prone according to Seoul's future disaster performance standards (rainfall treatment standards). Among these, the districts with the most basement dwellings in flood-prone areas are Gangnam-gu (1,374 units, 9.1%), Gangbuk-gu (1,367 units, 9.1%), Dongjak-gu (1,308 units, 8.7%), Eunpyeong-gu (1,259 units, 8.3%), Seongbuk-gu (1,254 units, 8.3%), and Jungnang-gu (1,137 units, 7.5%).

 

Senior Researcher Seo Sang-yeong emphasized that not all basement dwellings face high flood risks and that a careful and gradual policy approach is needed to protect the lives and well-being of residents facing repetitive flooding. He also stressed the importance of considering factors such as the aging of buildings and infrastructure (roads) in addition to flood risk when formulating policies for basement dwellings. He recommended actively pursuing small-scale housing redevelopment projects (collective housing and townhouse projects) and redevelopment projects in densely populated areas for effective risk reduction.

 

During the policy forum, proposals were made for Seoul's flood prevention measures, including standards for installing flood barriers and expanding their installation. Kim Seong, a sub-researcher at the Environmental Safety Research Laboratory of the Seoul Research Institute, presented the second topic titled "Expansion of Flood Barrier Installation in Seoul's Basement Dwellings." Kim pointed out that while Seoul is expanding flood barrier installations, there is a lack of appropriate standards, and some condominiums have negative perceptions of flood barrier installations, making it difficult to expand their use.

 

Kim emphasized the need for criteria to classify areas in Seoul that require flood barrier installation, similar to the zoning system used in the United States and the United Kingdom based on flood risk levels (Zones 1-3). This classification would help clearly identify high-risk flood areas.

 

Kim further proposed, "To install flood barriers effectively, they should be placed at least 50 cm above ground level, considering the flood characteristics and expected flood depth at points where surface water can enter. Additionally, measures should prioritize evacuations, including securing evacuation time for basement dwelling residents who may be affected by floods."

 

Addressing the basement dwelling issue in Seoul is a crucial challenge for ensuring the safety and stability of residential environments. A careful approach and policy development regarding this issue will play a significant role in enhancing the safety and convenience of underground housing residents in Seoul.