On July 23, information from Ban Ve Hydropower Plant said that due to the impact of storm No. 3, a particularly large flood occurred in the Ban Ve Hydropower Reservoir Basin.
At 4:00 a.m. on July 22, the Ban Ve Hydropower Reservoir Basin began recording a large flood with an input flow of 583 m3/s and the lake water level reached 189.08 m. Within 6 hours, the flood suddenly increased, reaching 1,500 m3/s at 10:00 a.m., causing the water level to rise to 189.69 m.
Next, the Company received an operating order to regulate flood reduction from the Steering Committee for Natural Disaster Prevention, Search and Rescue and Civil Defense of Nghe An province. At 4:00 p.m. the same day, the lake began to release floodwaters with a total flow of 845 m3/s, of which 508 m3/s passed the spillway (the valve gates were completely opened), ensuring that the lake's water level was still below the flood threshold (191.23 m compared to 191.5 m according to regulations).
The flood peak poured into the lake at 12,800 m3/s at 2:00 a.m. on July 23, higher than the designed flood level (10,500 m3/s).
However, the Company has controlled the situation well when it only released 3,285 m3/s, equivalent to a 74% reduction in flood flow, contributing significantly to reducing flooding in downstream areas.
Faced with the serious flooding situation in the downstream, the Company has proactively reported to the Chairman of Nghe An Provincial People's Committee and requested to switch from the safe operation regime of the project to unusual operation to minimize water discharge, continue to support to minimize the impact on people.
