Flood exceeds peak, Ban Ve Hydropower Plant cuts 74% of flow downstream

Due to the impact of storm No. 3, an exceptionally large flood occurred in the Ban Ve Hydropower Reservoir basin, exceeding the flood control frequency, with a peak flow of up to 12,800 m³/s at 2:00 a.m. on July 23. In the face of the emergency, Ban Ve Hydropower Company promptly switched to an unusual operation mode, cutting down 74% of the flood flow downstream, contributing significantly to limiting damage caused by flooding.

Báo Nghệ An•23/07/2025

The flood started at 4am on July 22 with a flow rate of 583 m³/s, the lake water level was at 189.08 m. By 10am the same day, the flood flow rate increased rapidly to 1,500 m³/s, the lake water level increased to 189.69 m.

Faced with this development, at 10:15 a.m., Ban Ve Hydropower Company received orders to regulate and reduce flooding downstream from the Steering Committee for Flood and Storm Prevention and Control and Disaster Prevention of Nghe An province.

At 4:00 p.m. on July 22, the company began operating the flood discharge through the spillway with a flow rate of 508 m³/s (valve gates fully open), the total discharge through the project reached 845 m³/s, while the lake water level increased to 191.23 m, close to the lowest flood level according to the design (191.5 m).

Ban Ve Hydropower Plant reaches flood peak water flow. Photo: CSCC

The peak of the flood occurred at 2:00 a.m. on July 23, when the water flow into the lake peaked at 12,800 m³/s, exceeding the project's test flood flow of 10,500 m³/s.

During this time, Ban Ve Hydropower Plant only discharged at a flow rate of 3,285 m³/s, cutting the water volume by 74%, helping to greatly reduce the pressure on the downstream area that is deeply flooded.

Flood reduction caused the lake water level to rise rapidly, forcing the company to switch from safe operation mode to abnormal operation mode. However, in the face of serious flooding downstream, Ban Ve Hydropower Company reported and asked for the opinion of the Chairman of Nghe An Provincial People's Committee to continue operating flexibly, minimizing the amount of water discharged, and supporting flood reduction in low-lying areas.

This is considered one of the rare major floods in recent years. Thanks to proactive, timely and flexible operations, Ban Ve Hydropower Plant has ensured the safety of the project, while also contributing significantly to minimizing damage to the downstream area.

Currently, the flood situation in the western region of Nghe An is still complicated. The authorities are actively monitoring and implementing on-site response plans to ensure the safety of life and property of people in the affected areas.

Source: https://baonghean.vn/lu-vuot-dinh-thuy-dien-ban-ve-cat-giam-74-luu-luong-ve-ha-du-10302948.html