South issues advisories as water levels surge after surprise dam release by North
Despite agreeing to notify Seoul, Pyongyang's radio silence continued before a surge of water hit the Pilseung Bridge area of the Imjin River, triggering advisories.
Gunnam Dam in Yeoncheon County, Gyeonggi, discharges water on July 15.YONHAP
As heavy monsoon rain batters the peninsula, North Korea has once again caught the South off guard — not with a sudden missile launch, but with a release of water from a border dam.
The water level at Pilseung Bridge, located at the northernmost point of the Imjin River in the South's Yeoncheon County, Gyeonggi, rose sharply overnight on Tuesday, triggering an emergency evacuation notice in the county.
The water level at the bridge stood at 4.31 meters (14.1 feet) as of 8:50 a.m. Tuesday, up 3.58 meters from 0.73 meters recorded at around 5 p.m. the previous day, according to the Han River Flood Control Office.
Flood risk along the Imjin River is managed under a four-tier warning system based on the water level at Pilseung Bridge. When the level exceeds one meter, authorities advise people along the river, including visitors and campers, to evacuate. When the river rises to two meters, mandatory evacuation for nearby residents is activated, regardless of whether it is flood season. A reading of 7.5 meters activates the so-called concern level for emergency response in border areas, while 12 meters raises the alert to the highest caution level.
When the water level rose to one meter at 12:20 a.m. Tuesday, Yeoncheon County in northern Gyeonggi sounded evacuation sirens and sent emergency text alerts reading: "People along the river, including visitors, campers, fishers and nearby residents, are urged to evacuate immediately to a safe location."
The Ministry of Climate, Energy and Environment assessed that the North had begun discharging water from its Hwanggang Dam upstream, based on routine satellite imagery taken at 8:47 p.m. on Monday.
Fire personnel participate in a rescue training session in case of flood on the Imjin River in Gyeonggi on May 20, 2025.YONHAP
Authorities believe Pyongyang released water from the dam after heavy rain hit North Korea from last Friday to Sunday, with additional downpours forecast through Tuesday. The regime-controlled Korean Central TV reported that its weather agency had issued the fourth heavy rain advisory of this year's monsoon season.
The dam, built more than a decade ago, can hold 350 million tons of water — nearly five times as much as South Korea’s flood-control Gunnam Dam in Yeoncheon. The two dams are separated by just 56.2 kilometers (35 miles).
Water released from Hwanggang Dam, located 42.3 kilometers north of the military demarcation line, takes about nine hours to reach Pilseung Bridge if discharged at a rate of 500 tons per second.
Because water reaches downstream areas in a short time, advance notice from North Korea — which was agreed upon 17 years ago — could significantly reduce flood risks.
The Imjin River swells in Yeoncheon County, Gyeonggi, on July 10.YONHAP
North Korea did not provide prior notification of the latest release.
In September 2009, an unannounced discharge from Hwanggang Dam caused fatalities downstream along the Imjin River on the South’s side. The two Koreas agreed the following month to notify each other before future releases. However, Pyongyang has not provided advance notice since 2013.
"We will continue analyzing additional satellite imagery and closely monitor water levels at Pilseung Bridge to prevent damage to residents in border areas," the ministry said.
Separately, the Korea Meteorological Administration briefly issued a heavy rain advisory for Yeoncheon and northwestern parts of Paju in Gyeonggi at 3:10 a.m. Tuesday before lifting it about three hours and 20 minutes later.
This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
