Seoul Flooded in Just 14 Hours, Gimpo and Incheon under Water

It was confirmed on October 5 that the government has prepared an “Emergency Action Plan” (EAP) that prepares for a worst-case scenario in which the Soyang River Dam collapses due to heavy rainfall and the metropolitan area, including Seoul, becomes flooded.

According to data submitted by the Ministry of Construction and Transportation (MOCT) to Representative Huh Cheon, who sits on the National Assembly’s Construction and Transportation Committee, the Korea Water Resources Corporation (KOWACO) drafted the EAP in December 2002. The plan, which specifies the areas likely to go under water in the case of the Soyang River Dam’s disintegration as well as evacuation sites for local residents, is classified as “permanently confidential.”

The EAP posits a situation in which precipitation of 632mm or more falls over the 100km² area surrounding the Soyang River Dam in Chuncheon, Gangwon Province within a 24-hour period. If the Soyang River Dam breaks, Chuncheon will be almost completely flooded in two hours and 57 minutes. The estimated time of flooding is two hours and 58 minutes for the Uiam Dam, five hours nine minutes for the Cheongpyeong Dam, and eight hours 47 minutes for the Paldang Dam, while Seoul is expected to suffer significant water damage within 14 hours and 22 minutes. A total of 47 cities, counties, and districts in the metropolitan area will become submerged.

Half of Seoul under Water—

Simulation tests conducted by the MOCT and KOWACO show that the water pouring into the river when the Soyang River Dam breaks will reach Seoul in a matter of less than five hours. Over the succeeding nine hours, the level of the Han River will continue to rise and cause water damage across all 25 districts in Seoul.

The EAP’s flooding prediction chart forecasts that districts abutting the Han River including Mapo, Yangcheon, Yongsan, Yeongdeungpo, Songpa, and Seocho, and those in the Jungnang Stream area including Seongdong, Gwangjin, Jungnang, Dongdaemun, and Nowon, will be under 5m or more of water.

The Seoul World Cup Stadium in Mapo, the KBS and MBC broadcasting stations in Yeouido, and the Yongsan USFK base are expected to be completely submerged. The only areas likely to escape water damage in Mapo are parts of Ahyeon-dong and the World Cup Park, while in Yeouido all areas excepting the National Assembly Hall are expected to be under water.

South of the Han River, the flooding is expected to reach all the way to the city of Seongnam in Gyeonggi Province, with more than half of Gangdong, Songpa, and Seocho falling prey to the encroaching waters. Certain areas of Gangnam will also suffer damage.

The Han River will reverse its flow up the Jungnang Stream to cause flood damage in the districts of Dongdaemun, Jungnang, Gwangjin, and even Nowon. The water will reach as far as the Dongdaemun area and the neighborhood fronting Korea University.

But in Jongno, which is largely hilly and mountainous, such districts as Seodaemun, Gangbuk, Dobong, and Eunpyeong will suffer relatively less damage. Government buildings, including the Central Government Complex and the police headquarters, and various news agencies located in the area are expected to escape largely unscathed.

The flood water is expected to recede from Seoul in approximately 43 hours.

Chuncheon, Gimpo Almost Completely Submerged—

The EAP predicts that the city of Chuncheon will become flooded within three hours of dam breakage, excluding the Mount Bongui area.

Hanam and Guri, both located near the Han River, will suffer heavy flood damage, while parts of Gwangmyeong are also likely to fall under water.

Part of the water traveling past Chuncheon into Paldang will flow backward into the South Han River and cause flood damage in Gwangju, Yangpyeong, Yeoju, and Icheon.

In the city of Goyang, which lies further down the Han River, the entire district of Deokyang will become submerged, except for the Freedom Highway, the Lake Park area, and the Haengju Mountain Fortress. Gimpo will also be almost completely flooded, with Incheon also suffering flood damage across a significant number of districts.

In-Jik Cho Kang-Myoung Chang cij1999@donga.com tesomiom@donga.com