According to information from the Power Generation Corporation 1, flooding began at 4:00 AM on July 22, with a flow of 583m³/s. The flow quickly increased to 1,500m³/s by 10:00 AM on the same day, with the reservoir's water level at 189.69 meters.

In compliance with the directive from the Disaster Prevention and Search and Rescue Command and Civil Defense of Nghe An Province to reduce the flood flow for the downstream, the reservoir began releasing floodwater at 508m³/s through the spillway at 4:00 PM, combined with a release through the power station at 845m³/s. The water level at that time was 191.23 meters (the lowest flood reception level is 191.5 meters).

At the flood peak (2:00 AM on July 23), the total water release was 3,285m³/s, and the reservoir reduced about 74% of the peak flood flow to lessen the flood impact on the downstream.

The reduction of floodwater for the downstream by retaining 74% of the peak flood flow at the hydropower reservoir caused the water level to rise rapidly, and the reservoir gradually shifted to an operational mode, ensuring the safety of the infrastructure.

This was an exceptionally large flood, exceeding the design flood frequency (the check flood flow for the Ban Ve Hydropower Plant is 10,500m³/s), but the company operated to ensure the absolute safety of the key infrastructure, significantly contributing to the reduction of floodwater for the downstream.

Translator: Thu Hường