Ensuring safety of dams, reservoirs and downstream areas

Currently, units are implementing solutions to ensure the safety of dams, irrigation and hydroelectric reservoirs and downstream areas of lakes and dams, especially hydroelectric reservoirs in the Vu Gia - Thu Bon river basin where water levels are high.

A Vuong Hydropower Reservoir is at approximately the lowest flood level, so the work of operating to ensure the safety of the reservoir, dam and downstream is being focused on and strengthened. Photo: HOANG HIEP

Flood storage capacity will not be much.

At this time in previous years, the water level of hydroelectric reservoirs in the Vu Gia - Thu Bon river basin had lowered, reaching the dead water level on August 31 every year to transition to the flood season operation period.

However, currently, the water level in 5 large hydroelectric reservoirs including: Song Tranh 2, Dak Mi 4, A Vuong, Song Bung 4 and Song Bung 2 are all very high.

At 7:00 a.m. on August 25, the Dak Mi 4 and Song Bung 2 hydropower reservoirs were still higher than the lowest flood water level as prescribed, in which the water level of Song Bung 2 hydropower reservoir was almost full (604.22m/605m).

As for A Vuong hydroelectric reservoir, the water level is approximately at the lowest flood level (369.98m/370m).

With the flood prevention capacity of these 5 large hydroelectric reservoirs not being much, it is likely that after only 1-2 floods at the beginning of the season, the reservoirs will be full, making it difficult to cut and reduce floods downstream this year if many floods occur.

Deputy General Director of A Vuong Hydropower Joint Stock Company Ngo Xuan The acknowledged: “With the current water level of A Vuong Hydropower Reservoir, only a rain of about 250mm will fill the reservoir. By the afternoon of August 23, the company had completed all inspections of related machinery and equipment; and prepared all conditions to ensure safe operation of the reservoir, hydropower dam and downstream during the flood season.”

For Dak Mi 4 Hydropower Reservoir, the water level at the above time (253.08m) is nearly equal to the water level in the flood reduction and operation scenario corresponding to the flood peak at the reservoir of 5,500m3/s (253.7m) that Dak Mi Hydropower Joint Stock Company has built.

Vice Chairman of Da Nang City People's Committee Tran Chi Cuong (4th from left) inspected the operation of A Vuong Hydropower Plant on August 20, 2025. Photo: HOANG HIEP

From this scenario, the company flexibly adjusts the cut rate and reduces floods most effectively to ensure the safety of the reservoir and downstream.

Deputy General Director of Dak Mi Hydropower Joint Stock Company Nguyen Thanh Binh said that Dak Mi 4 Hydropower Reservoir has a high basin slope and the correlation coefficient between the basin area (1,125km2) and the useful capacity of the reservoir (158.26 million cubic meters) is very large, so the flood comes quickly. Therefore, the company calculates, builds a water regulation plan and operates the reservoir according to the scenario to proactively operate to ensure the safety of the reservoir, dam and downstream.

In addition, as soon as there was a forecast of rain and flood in the basin, the company deployed many tasks related to the preparation of reservoir operations to respond. The company arranged a 24/24-hour natural disaster prevention schedule with at least 2 technical staff with extensive experience in flood calculation and regulation; increased 4 workers to operate flood regulation and promptly handle damage and incidents, and workers to directly monitor, collect and report hydrological data to serve timely flood calculation and regulation.

Deputy Director of the Department of Agriculture and Environment Truong Xuan Ty said that irrigation lakes in the city are below normal water level, ensuring safety.

Of the 5 large hydroelectric reservoirs in the Vu Gia - Thu Bon river basin (Song Tranh 2, Dak Mi 4, A Vuong, Song Bung 4, Song Bung 2), 3 have water levels in the safe zone, that is, lower than the lowest flood level (Song Tranh 2, A Vuong and Song Bung 4 hydroelectric reservoirs).

The two hydroelectric reservoirs Song Bung 2 and Dak Mi 4 are higher than the lowest flood water level.

Currently, the reservoir management and operation units have plans and are preparing conditions to ensure reservoir operation and respond to natural disasters. The Department of Agriculture and Environment continues to coordinate with units to organize the safe operation of reservoirs and dams during the flood season.

Strictly implement regulations on safety of lakes and dams

According to the Department of Water Resources and Irrigation Management (Department of Agriculture and Environment), currently in Da Nang city, there are 12 dams and reservoirs being invested in upgrading and repairing and have been basically completed, including Loc Dai, Ho Do, Phuoc Hoa, Thai Xuan, Da Vach, Cao Ngan, Huong Mao, Ho Giang, Trung Loc, Dong Tien, Ho Cai, and Nuoc Zut lakes.

Vice Chairman of Da Nang City People's Committee Tran Chi Cuong (third from right) inspects the operation of Dak Mi 4 hydropower reservoir on August 20, 2025. Photo: HOANG HIEP

The City People's Committee has assigned the Department of Agriculture and Environment to preside over and coordinate with the Department of Finance and relevant units and localities to continue reviewing, proposing repairs, upgrading, and ensuring the safety of dams and irrigation reservoirs; arranging public funding sources, enterprise financial capital sources, and development investment capital sources to implement regulations on dam and reservoir safety according to Decree No. 114/2018/ND-CP of the Government .

The Department of Water Resources and Irrigation Management (Department of Agriculture and Environment) said that, in the face of the high water level in hydroelectric reservoirs, the City People's Committee issued Official Dispatch No. 1070 dated August 13, 2025 directing departments, wards, communes and units to strictly implement regulations on safety management of dams, hydroelectric reservoirs and operations to ensure absolute safety for the works as well as downstream areas in the coming time.

To ensure the safety of dams and irrigation reservoirs, the City People's Committee continues to issue Official Dispatch No. 1396 dated August 22, 2025, assigning Da Nang Irrigation Exploitation Company Limited and Quang Nam Irrigation Exploitation Company Limited to make a plan to organize repairs and immediately fix minor damages; arrange qualified personnel for operation; organize on-duty shifts during the rainy and flood seasons and assign permanent staff to the construction site.

At the same time, regularly check the safety of the works even when there is no rain or flood to detect and handle the incident at the first hour; test the operation of the sluice gates and equipment serving flood discharge of the reservoirs; strengthen monitoring, update weather forecasts, hydrometeorology and apply advanced technologies to support reservoir regulation, ensure the safety of the works and the downstream area of ​​the dam.

The People's Committees of communes and wards shall intensify propaganda and training on knowledge and skills to respond to natural disasters for people in the downstream areas of dams and reservoirs. At the same time, review and update plans to evacuate people in the downstream areas of dams and reservoirs and coordinate with forces to proactively and promptly organize response when incidents occur.

Source: https://baodanang.vn/bao-dam-an-toan-dap-ho-chua-va-ha-du-3300327.html