It was a record heavy rain… Last year’s floods were caused by overall poor management of the dam.

The results of a government service survey showed that the flood damage that occurred in the downstream areas of the dams such as Seomjingang Dam and Yongdam Dam last year was the result of a combination of unusually concentrated heavy rain caused by climate change and poor dam management.

The Ministry of Environment held a briefing at the government complex in Sejong on the 3rd and announced the results of the investigation on the cause of flood damage conducted by the Korean Water Resources Association in December of last year and future measures for the residents of the affected area.

As a result of the investigation, it was revealed that the primary cause of flood damage was record heavy rain, but the dam management regulations and guidelines and manuals did not properly reflect the changes in climate conditions over the decades, and it was found that the flood was not properly responded to. Last year, the rainy season lasted for 54 days (based on the central region), the longest period ever, and the amount of precipitation recorded 687 mm, the second highest since 1973. However, the Korea Water Resources Association pointed out that even though the increase in precipitation due to climate change did not happen overnight, the changes in these conditions were not properly reflected in the flood protection plan so far.

For example, in the case of the Seomjingang Dam, the flood control capacity was 6.5%, which was only about 40% of the national average (17.2%). Structurally, the situation was not able to respond to the flood. Bae Deok-hyo, president of the Korea Water Resources Association, said, “Efforts to reflect changes in conditions caused by abnormal weather have been insufficient for a long period of time.

Actual dam operation management was also insufficient. Dams should be operated with the water level adjusted according to regulations during the flood season, but the water level at the beginning of the flood period was maintained high even during the prolonged heavy rain, and in some dams, the water level exceeded the limit water level during the flood season. As a result of the service survey, the forecast for the end of the rainy season was erroneous for Yongdam Dam, and complaints arose in the downstream areas, so the flood season limit was exceeded. It was found that the Seomjingang Dam was structurally difficult to respond to flood damage as the flood flow exceeded the design frequency of the dam. In addition, when the dam is discharged, the residents living in the downstream area are notified later than the prescribed time, which led to a lack of response time.

The government announced that it will expedite the environmental dispute mediation process requested by residents of the affected area. Currently, victims of Hapcheon-gun, Cheongju-gun, and Gurye-gun have applied for environmental dispute mediation. In addition, the disaster recovery project in the damaged area, which is still in progress, will be completed by the beginning of next year, and flood management will be strengthened in preparation for the climate crisis based on the innovative comprehensive measures to respond to storms and floods announced in November last year. Flood season measures were also announced. The Ministry of Environment said, “We are operating the dams by lowering the water level, such as setting a separate upper water level for each dam so that flood control is possible even in the torrential rains of last year or more.”