The Ministry of Environment made a statement on the flood-prevention effects of the Four Major Rivers Project (Han River, Nakdong River, Geum River, Yeongsan River) promoted by the Lee Myung-bak government and announced, “The dams built by the Four Major Rivers Project were not effective in preventing floods.” The ministry refuted the argument of the United Future Party, which claimed that the areas surrounding the Seomjin River suffered from massive floods because the river was not part of the Four Major Rivers Project.

The Korea Water Resources Corporation (K-water), under attack for mismanaging the dams and aggravating the damage as the nation suffered from the longest monsoon in history, claimed that the damage was big because more rain fell than was forecasted by the Korea Meteorological Administration.

The environmental ministry held a press briefing on August 12 and argued that based on past surveys and data in connection to the Four Major Rivers Project, “The dams built as part of the Four Major Rivers Project actually raised the flood levels (water level during a flood), having a negative impact on flood control.” According to the ministry, an investigation by the Four Major Rivers Project Evaluation Committee in 2014, during the Park Geun-hye government, and the audit results of the Board of Audit and Inspection in 2018, in the incumbent government, both concluded that the dams constructed in the four rivers actually raised flood levels.

However, the conclusion at the time was based on an analysis of a virtual flood model, so the environmental ministry announced it would conduct an empirical study based on the actual measurements during this year’s floods according to the instructions of the president. An official from the environmental ministry said, “Since we have all the data on the latest flood damage, it will not take long to compare the figures with pre-dam figures.”

The Ministry of Environment refuted the argument by the United Future Party that Seomjin River experienced greater damage, because it was not part of the Four Major Rivers Project and simply argued, “It is not true.” The environmental ministry official explained, “A particularly large amount of rainfall was concentrated in the Seomjin River region, and in the case of the lower reaches of the river, they had rains that come around only about once in 500 years, which was why the damage was big.”

Local governments and residents around the Seomjin River Dam and Yongdam Dam suffered damages from the rain and are demanding K-water for compensation and measures to prevent recurrence. They argued that despite forecasts of an unprecedentedly long monsoon and torrential rains, K-water failed to properly adjust the water level at the dams and increased the damage. K-water explained, “We have no choice but to rely on the predictions by the Korea Meteorological Administration, but we had more rainfall than was forecast.”

Yi Han-gu, a director at K-water said, “We tried to reduce the damage downstream, but our actions were inevitable for the safety of the dam,” and mentioned the need to change future dam designs according to climate changes. Yi said, “Since we are experiencing climate change, there is a wide gap between the performance expected when designing the dam and the actual performance when it is in operation,” and argued, “We need a national system for our dams and streams to comprehensively prevent floods.”