Heavy rain accompanied by strong winds hit Seoul on Sunday, the 18th, flooding roads and knocking down trees. Gangbuk District at one point recorded downpours exceeding 50 millimeters per hour, and water rose quickly in some areas as fallen leaves blown off by the winds clogged storm drains.
The Seoul Metropolitan Government said fire authorities had received a total of 129 reports of rain-related damage as of 5 p.m. These included 47 requests for drainage assistance, 21 cases of fallen trees and 60 reports related to the safety of other facilities.
Gangbuk District recorded 53.5 millimeters of rain in one hour, the highest hourly rainfall in the country. Its cumulative rainfall through 5 p.m. also led Seoul at 65 millimeters. Songpa District, by contrast, logged the least at 20 millimeters, a wide gap across districts.
The intense rainfall over a short period raised flooding concerns. The city issued successive flood alerts, starting with Eunpyeong District at 2:42 p.m., followed by Gangbuk District at 2:50 p.m. and Nowon District a minute later. Access was also restricted at 16 streams in the city, including Jungnangcheon, Yangjaecheon, Uicheon and Seongbukcheon.
Road closures followed across the city. The road beneath Jeungsan Bridge in Seodaemun District was fully closed after flooding at around 3:04 p.m., and Yeongdeungpo District blocked traffic on a four-lane road in the Yeongdeungpo 8-ga area at around 2:55 p.m. because of the risk of falling objects. Advisories were also issued to watch for wet roads and strong winds on the Yangjae-Anseong section of the Gyeongbu Expressway and the Geumcheon-Seo Pyeongtaek section of the West Coast Expressway.
In Yeoksam-dong, Gangnam District, a tree toppled onto a road in a gust of wind, disrupting traffic and pedestrians. A road near Yeonsinnae Station in Eunpyeong District was also flooded, slowing vehicles. Water was reported to have risen above knee level in some areas.
Fallen leaves driven down by the winds added to the flooding. Where leaves blocked storm drains and rainwater could not drain away in time, water pooled quickly on roads. Some merchants and residents cleared leaves from around the drains themselves.
Outdoor events were disrupted as well. The Grand Mint Festival at Olympic Park in Songpa District canceled some performances because of the weather and issued refunds. The Mapo Naru Salted Shrimp Festival at World Cup Park in Mapo District was also halted for safety reasons.
The city went on Level 1 emergency duty from 2:40 p.m. to respond to the damage. It partially activated 12 rainwater pumping stations and worked with district offices to clear leaves from storm drains and drain flooded areas. At around 3:16 p.m., it sent an emergency text message urging residents to avoid low-lying and hazardous areas and to watch for falling signs and other fixtures.
Heavy rain advisories for the northeastern, northwestern and southwestern parts of Seoul were lifted as of 3:30 p.m. Rain continued in some areas afterward. "The rain appears to be easing for now, but reports of damage are still coming in, so we are focusing our response on resolving them quickly," a Seoul city official said.