Lang Son: Initial information on the cause of the Bac Khe hydroelectric dam collapse

On the afternoon of October 7, the People's Committee of Tan Tien commune, Lang Son province reported on the situation of the Bac Khe 1 hydropower dam collapse, due to the impact of storm No. 11.

Scene of the Bac Khe hydroelectric dam ( Lang Son ) breaking on the afternoon of October 7, 2025. Photo: VNA

According to Vice Chairman of Tan Tien Commune People's Committee Nguyen Manh Tuan, due to the impact of storm No. 11 (MATMO), from the morning of October 6 to 7, Tan Tien Commune continuously had heavy rain, sometimes very heavy rain. According to the update at 9:00 on October 7 of Bac Khe Hydropower Plant, the water flow to the lake was 1,181 m3/s, the water flow to the downstream was 1,181 m3/s.

Bac Khe Hydropower Plant last updated at 12 noon the same day, water flow to the lake was 1,562 m3/s, water flow downstream was 1,562 m3/s. At 1:30 pm, it caused the Bac Khe 1 Hydropower Dam to collapse.

Bac Khe 1 Hydropower Plant in Bac Khe village, Tan Tien commune with installed capacity of 2.4M, basin area of ​​325 km2, water flow of 1,572 m3. The broken dam section is about 4 - 5m long and 3 - 4m deep.

According to initial assessment, the cause of the dam failure was due to prolonged heavy rain, the peak water flow reached 1,572 m3/s, causing a concrete slab at the water intake to break, and the central control room and equipment in the room to collapse. There have been no recorded human casualties; property damage has not been counted.

Currently, Lang Son province leaders and local authorities are trying to reach the scene and direct the handling of the incident. The Commune Civil Defense Command has urgently notified the villages in the surrounding areas of Bac Khe 1 Hydropower Plant and the downstream areas of communes such as That Khe, Trang Dinh, Khang Chien, and Quoc Viet through communication means such as telephone, zalo groups, etc. so that the authorities of the communes can notify people to evacuate from the dangerous area, ensuring safety of life is the top priority.

Police, military , militia, medical, and rescue forces are ready to join in searching and evacuating people from dangerous areas. Because National Highway 3B is currently still cut off at many points, it is difficult to respond to this incident.

Source: https://baotintuc.vn/xa-hoi/lang-son-thong-tin-ban-dau-ve-nguyen-nhan-vo-dap-thuy-dien-bac-khe-20251007163551087.htm