Hydropower plant discharges water abnormally, causing damage to embankment project in downstream area of ​​Bac Kan

Thac Gieng 1 Hydropower Plant has repeatedly released water unexpectedly, causing heavy damage to the projects under construction at the Chu River and Cau River embankment project through Dong Tam town, Cho Moi district, Bac Kan province.

Hydropower plant releases water unexpectedly, causing damage downstream

According to the feedback from contractors at the project of Embankment to overcome landslides on the banks of Chu River and Cau River, recently Thac Gieng 1 Hydropower Plant, Xuat Hoa Ward, Bac Kan City suddenly released water many times without warning, causing water to rise, affecting and damaging the works under construction.

Floodwaters flooded the construction works under construction at the project to repair landslides on the banks of Chu and Cau rivers through Dong Tam town, Cho Moi district on November 5. (Photo provided by the unit)

An official from the Bac Kan Province Agriculture and Rural Development Project Management Board (investor) said that the project to repair landslides on the Chu and Cau River banks through Dong Tam town started construction on September 15, and to date the estimated construction volume has reached more than 10%.

This embankment project has a total length of 1,912m on the left bank of the Cau River, with a total investment of 63.3 billion VND (the central budget reserve in 2023 is 60 billion VND, the provincial budget is 3.3 billion VND), according to the project requirements to be completed in 2024.

However, on November 5, the above project encountered an incident when Thac Gieng 1 Hydropower Plant (of Song Da Bac Kan Joint Stock Company, Xuat Hoa Ward, Bac Kan City) suddenly released water, causing flooding, sweeping away many machines and unfinished construction items.

According to Giao Thong Newspaper's reporter on November 14, the water has basically receded and workers are constructing the items.

A construction supervisor at the site said: At about 3:20 a.m. on November 5, water flowed to the construction site.

Due to lack of prior notice, many construction machines were unable to move to higher ground and were flooded and severely damaged. Many foundation pits and dikes that had been dug were flooded and eroded. Many equipment were swept away by the water. The estimated damage was around 122 million VND.

Mr. Tung - a worker working on the project said: The incident happened at night so no one knew, it was only discovered when the water was completely flooded.

After many days of pumping water, the project has resumed construction, but it is difficult to meet the year-end schedule.

Workers and machinery are working at the project.

Workers and machines were mobilized urgently to speed up progress.

Similar incident happened

According to Giao Thong Newspaper, as of November 14, the water has completely receded in the entire flooded area. The teams have started to return to work.

At the construction site, workers and machines were mobilized to quickly make up for the time lost due to the incident.

Also according to the project investor representative, previously, at around 8:00 a.m. on October 19, Thac Gieng 1 Hydropower Plant also released water without prior notice, causing the water level of Cau River and Chu River downstream to rise nearly 3m above normal water level.

At that time, water also overflowed the dike, affecting the progress and quality of construction of downstream projects.

On October 19, Thac Gieng 1 Hydropower Plant also released water, causing the water level of Cau River and Chu River to rise, making construction work difficult.

To ensure the progress and quality of construction, the Project Management Board of Agricultural and Rural Development Projects of Bac Kan province has worked with and requested Song Da Bac Kan Joint Stock Company (the unit managing Thac Gieng 1 Hydropower Plant) to release water for electricity generation at fixed times of the day and provide the release schedule to the Board.

However, Song Da Bac Kan Joint Stock Company later discharged water many times outside the provided time frame, leading to the above damage.

After that, to avoid repeating the unfortunate incidents of October 19 and November 5, the Project Management Board of Agriculture and Rural Development of Bac Kan province sent a distress call to the People's Committee of Bac Kan province and related parties.

Water overflowing the dike affects the progress and quality of construction of downstream projects.

Mr. Dinh Huy Hoang, Director of the Department of Agriculture and Rural Development Project Management in Bac Kan province, said: Immediately after the incident, the unit sent a dispatch to the Department of Industry and Trade, and at the same time, the Department of Industry and Trade reported to the Provincial People's Committee to direct Song Da Bac Kan Joint Stock Company to coordinate with contractors to compensate for the damage. However, as of November 14, the hydropower plant has not yet coordinated.

Many downstream areas were affected by unusually high water levels during project construction.

Reasons for Thac Gieng 1 Hydropower Plant releasing water

Regarding this, Mr. Dinh Lam Sang - Deputy Director of the Department of Industry and Trade of Bac Kan province said: The Department has received a report from Song Da Bac Kan Joint Stock Company about the incident of Thac Gieng 1 Hydropower Plant releasing water causing damage to construction works under construction downstream.

The construction unit is rushing to implement the project to complete the progress in 2024.

Accordingly, Thac Gieng 1 Hydropower Plant reported that the cause of the incident was that after storm No. 3, a large amount of soil and rock on the slope of Highway 3B slid down to the operating road and water intake, burying the water intake, leading to the plant being unable to generate electricity since September 8.

To resume operation of the plant, the unit dredged the amount of soil and rock that buried the water intake from October 19 to November 2.

During this time, the reservoir did not store water and opened the bottom spillway to allow natural flow. At 8:00 p.m. on November 2, the hydropower plant allowed the reservoir to store water again and at 9:00 p.m. on November 4, the unit started generating electricity.

However, at this time, the water intake gate had an accident and could not be raised and the lake water level rose, so the dam's spillway gate had to be opened according to the operating procedure with a flow rate equivalent to the water flow rate for generating electricity at a water level of 5.5MW capacity (flow rate ^55m3 to ^60m3 /s).

The cause was an accident at Thac Gieng 1 hydroelectric plant.

By 9:00 a.m. on November 5, the company had resolved the water intake gate problem and closed the dam's spillway.

Due to the above incident handling, the unit maintains the flow at a rate equivalent to the power generation flow, so according to the procedure, it only has to turn on the siren according to the reservoir operation procedure.

To clarify the issue of the unit not coordinating with contractors to compensate for damages, Giao Thong Newspaper reporters contacted the leaders of Song Da Bac Kan Joint Stock Company many times but were unsuccessful.

Source: https://www.baogiaothong.vn/thuy-dien-xa-nuoc-bat-thuong-gay-thiet-hai-cho-du-an-ke-vung-ha-du-bac-kan-192241114210714545.htm