There are only a few months left until the peak of the 2026 rainy and storm season, but the incident of partial dam breach at Bac Khe 1 Hydropower Plant, Tan Tien commune, Lang Son province, occurring from October 2025 to now has not been completely overcome.
In the afternoon of October 7, 2025, prolonged heavy rain caused the water flow to Bac Khe 1 Hydropower reservoir to increase sharply to about 1,572m3/s. High water pressure broke part of the dam area's concrete structure, causing damage to the operating house, central control system and some electrical equipment.
In the dam shoulder area, a sinkhole about 4-5m wide and about 3m deep appeared; the central control room collapsed, many equipment were flooded and heavily damaged.
Fortunately, nearly 800 people in the affected area were evacuated in time, so there were no casualties.
After the incident, Lang Son Provincial People's Committee directed emergency response; The Department of Industry and Trade coordinated with relevant agencies to inspect the scene and urge the investor to implement safety measures.
The unscheduled dam safety inspection was carried out after Decision No. 2253/QD-UBND dated October 16, 2025.
The inspection results completed in November 2025 proposed to construct additional concrete, expand the spillway width to 260m, and at the same time expand the canal section in front of the spillway according to the design by 55m to ensure flood drainage capacity according to the design frequency, in accordance with the current status of the project.
However, by mid-April 2026, the recovery progress was still assessed as slow and not meeting requirements.
Talking to reporters, Mr. Dinh Ky Giang - Deputy Director of the Department of Industry and Trade of Lang Son province - said that the incident at Bac Khe 1 Hydropower dam has not been resolved yet. Although the dam safety inspection has been completed, there are specific reports and recommendations, the implementation of repairs by the relevant unit is still slow.
According to Mr. Giang, functional agencies have repeatedly urged and continued to issue documents requesting supplementation of dossiers and implementation of urgent measures to ensure dam safety before the rainy and flood season.
Not only facing procedural obstacles, the Department of Industry and Trade also pointed out that the investor's organization of implementation is still clumsy and lack of proactiveness; the preparation of financial resources, human resources, and equipment for remediation has not met the progress requirements.
Notably, according to the assessment of specialized agencies, the project was constructed based on the results of basic design appraisal from 2007 and the decision to adjust the technical design in 2013 is not guaranteed according to the provisions of law on project management for construction investment.
The investor is required to hire an independent consulting unit to re-evaluate the entire quality and safety level of the dam; develop a plan to ensure safety for the project and downstream area; and at the same time review and complete all legal documents related to investment, construction and land.
Although it has been urged and requested to be supplemented many times, the investor has not yet submitted complete dossiers for specialized agencies to review and appraise.
In the times of inviting to work and actual inspections, the legal representative of the company was not present. This is identified as one of the reasons why the incident remediation is prolonged, while the rainy and storm season is very near.
Bac Khe 1 Hydropower Plant is a small hydropower project, with a reservoir capacity of about 4.8 million m3, a 107m long earth dam, a 260m long concrete spillway dam, a maximum height of 26.5m, and a 2.4MW installed capacity.
The factory is located quite isolated, about 400m from the main traffic route, so access and incident handling in the early stages face many obstacles.
