After days of torrential rain, North Korea on Wednesday released water from a dam near its border with the South without warning, stoking concerns of flooding among residents in riverside regions and prompting local officials to spread evacuation notices.

The North started opening the floodgates of Hwanggang Dam in the upper part of the Imjin River at around 6 a.m., Seoul’s military officials said, adding that the size of discharge flow was to be seen. Satellite images also found that the breadth of waterways in the region had widened from the previous 80 meters to 280 meters.

“They appear to have opened the gates step by step and the amount of water discharged increased,” a military official said. 

The military has not received any relevant advance notice, but it does not see it as a flooding attack, given recent downpours and past cases, he noted.

The unilateral release defied a 2009 agreement under which the North promised to give prior warning to the South of any discharge at the dam. It was made after six South Koreans were killed in September that year after North Korea released water from the dam without notice.

The Unification Ministry here also expressed regret over the move, urging Pyongyang to follow through on the agreement.

“If North Korea is sincerely interested in dialogue, peace and improving cross-border relations as it says all the time, it should show that it’s willing to cooperate on little things like the water discharge,” ministry spokesperson Jeong Joon-hee said at a regular news briefing.

The dam is about 42.3 kilometers north of the inter-Korean military demarcation line, with its estimated full capacity between 300 million to 400 million tons.

Last May, the North also released water from the dam twice without notice, affecting fishing families who could not retrieve their fishing gear.

With downstream water levels set to rise, Seoul’s Land Ministry and local government officials in Gyeonggi Province aired warning broadcasts and sent text messages in the neighborhoods, calling for residents to stay clear of the river.

By Shin Hyon-hee (heeshin@heraldcorp.com)