Checking the water intake culvert of Khe Ngang irrigation lake (Long Ho ward, Phu Xuan district)

Many dams are degraded.

According to the Hue City Irrigation Department, through visual inspection of dams and reservoirs in the area and testing of equipment, in general, dams and reservoirs operate normally, and no major incidents have been detected in new projects.

However, many auxiliary items have been damaged, some earth dams have landslides and slight seepage, mechanical equipment has degraded and has not been repaired or invested in. In addition, the flood discharge routes at the spillway and the gate of the reservoirs have been filled with silt, and grass has grown on the dam body.

In particular, the dam face, dam body, and downstream dam slope of Ben Van 1 and Ben Van 2 reservoirs were severely damaged, posing a risk of insecurity for the headworks. The spillway of Thuy Yen reservoir was eroded and at risk of expanding. The authorities have requested the People's Committee of Phu Loc district and the Hue City Irrigation Works Management and Exploitation Company (Irrigation Company) to promptly repair and fix the damaged items.

At the end of 2024, the Provincial Dam and Reservoir Safety Assessment Advisory Council (now Hue City) inspected and assessed 55 dams and reservoirs in the area. The inspection results showed that 5 dams had slight seepage, 4 dams had dam slope deformation. Checking the spillway, the council assessed that 7 dams had slight cracks, 17 dams had erosion of the body, tail of the spillway, and energy dissipation, of which 5 spillways were severely damaged.

In addition, the management and operation roads of some lakes have degraded, such as Khe Ngang Lake (low and flooded road), Hoa My Lake (dirt road has not been invested in), the access roads to the main dams of some local reservoirs have not been invested in, making travel very difficult, such as Ha Roi Lake, Khe Mang (Phong Dien Town), Con Thon Lake (Hue City).

In particular, according to the advisory council, the results of the inspection of the safety assurance contents of dams and reservoirs according to regulations showed that no reservoir had a procedure for operating the gate valve or a maintenance procedure for the project; 2% of the reservoirs were inspected according to regulations and 7% of the reservoirs had markers marking the protection range of dams and reservoirs.

The Irrigation Company said that the unit is managing 24 large, medium and small reservoirs in Hue City. Currently, only Khe Ngang irrigation reservoir was inspected in 2020 and is due for re-inspection; 5 other irrigation reservoirs in localities have just been upgraded and repaired according to investment programs and have been inspected and assessed for dam safety; the remaining reservoirs are due but have not yet been inspected for dam and reservoir safety due to lack of funds.

Need funding to implement

The city currently has 56 dams and reservoirs for irrigation. Of these, one reservoir is an important project related to national security, the Ta Trach reservoir, eight large reservoirs, the rest are medium and small, and 275 dams are distributed in localities. These dams provide water for nearly 62,000 hectares of agricultural land, providing more than 1.2 billion m3 of water for daily life, industry, combined with power generation, flood prevention, drought, and saltwater intrusion.

The Irrigation Department believes that ensuring the safety of dams and reservoirs has been inadequate in recent times. The main reason is that most of the irrigation reservoirs in the area were invested in and built a long time ago, and have gone through many stages of management and exploitation, leading to lost records, making it difficult to complete management records. Dam safety inspection and construction of flood maps for downstream areas require large funds to implement, while the budgets of localities and units are limited, so they have not been implemented synchronously.

Mr. Dang Van Hoa, Permanent Vice Chairman of the Advisory Council for Safety Assessment of Dams and Irrigation Reservoirs, said that in general, the allocation of funds and implementation of legal regulations on dam safety management still have many limitations, and localities and units have not proactively allocated funds to implement the contents according to regulations.

To ensure the safety of irrigation works in the city, the advisory council recommends that the People's Committee of Hue City and the Department of Agriculture and Rural Development direct localities and the Irrigation Company to establish inspection teams for reservoir works in their localities to provide specific instructions, close to the actual situation, and have plans to ensure the safety of the works during the 2025 storm season. At the same time, there is an overall assessment of the safety status of the dam's headworks, test operation of the sluice gates, equipment serving the operation of the reservoirs and periodic maintenance of mechanical equipment...

Localities and units also need to proactively develop plans and allocate funds to implement the contents of dam and reservoir safety management in accordance with the provisions of the 2017 Law on Water Resources and related decrees and regulations. In particular, regular periodic inspections and assessments of the current status of works are required to promptly detect and handle hidden dangers and damage to minimize damage caused by incidents.

According to Mr. Dang Van Hoa, localities and units need to proactively organize safety inspections of dams and irrigation reservoirs, periodically inspecting every 5 years to detect incidents, damage... and assess the safety level of dams and reservoirs according to national technical standards and regulations...

Article and photos: HA NGUYEN