According to an update from Hoa Binh Hydropower Company, by 3:00 p.m. on November 26, 2025, the upstream water level of Hoa Binh Lake was at 116.61 m; the water flow to the lake reached 1,039 m3/s; the total discharge was 1,603 m3/s; the power generation flow through the generators was also about 1,603 m3/s.
Implementing the inter-reservoir operation process in the Red River basin, Hoa Binh Hydropower Plant opened the bottom spillway at 5:00 p.m. on November 23 and closed at 9:00 p.m. on November 24.
After closing the spillway, the reservoir is currently only operating power generation through generators to regulate the flow downstream. The water flow downstream has decreased sharply, the water level downstream of Hoa Binh dam is about 5 m higher than the discharge time.
Previously, another bottom spillway was also opened from 2:00 p.m. on November 20 and closed at 5:00 a.m. on November 22. During this time, the water level downstream of Hoa Binh Hydropower Dam decreased rapidly from 12.74 m; causing the flow of Da River to fluctuate significantly.
Although November is the dry season, when the rainfall in the Da River basin is not large, Hoa Binh Lake still has to carry out many bottom discharge phases.
Talking to reporters, Mr. Pham Van Vuong - Director of Hoa Binh Hydropower Company - said that upstream water flows in massively, the continuous closure and opening of bottom spillways to reduce the lake water level and ensure safe operation of the hydroelectric reservoir.
"This year, the frequency of flood discharge is high, reflecting complex weather and floods. The regulation will depend on the amount of water flowing in and the direction of the National Steering Committee for Natural Disaster Prevention and Control," Mr. Vuong emphasized.
The water level and water flow parameters of the reservoir are continuously updated, reported to the Ministry of Agriculture and Environment through the Department of Dyke Management and Natural Disaster Prevention and Control and related agencies.
According to the hydrological forecast bulletin of the National Center for Hydro-Meteorological Forecasting on November 26, the water flow into Hoa Binh Lake in the coming days is expected to fluctuate slightly, mainly affected by upstream lake regulation and tidal fluctuations in the downstream.
However, if there is heavy rain or low pressure in the East Sea, the flow to the reservoir can increase dramatically, forcing the reservoirs to regulate strongly, directly affecting the water level downstream.
