Promptly renovate lakes and dams to serve disaster prevention and control.

Given the shortcomings, inconsistencies with current realities, and deterioration of many reservoirs and dams, Da Nang city is allocating local budget and coordinating with the Ministry of Agriculture and Environment to propose government support for the early renovation, upgrading, and new investment in several irrigation works to serve disaster prevention and control and ensure water supply for domestic use and production.

The An Trach dam is causing a difference in flood water levels between the upstream and downstream areas after more than 25 years of construction and urgently needs to be replaced with a new, modern, multi-purpose structure. Photo: HOANG HIEP

The dam is damaged and inadequate.

In reality, during the floods of recent years, the An Trach dam (Hoa Tien commune) has caused a difference in water levels on the Yen River (downstream of the Vu Gia River) between the upstream and downstream of the dam. The reason is that the structure was designed in an outdated style and built 25 years ago with large piles, making it obsolete and no longer suitable for extreme natural disasters and climate change. Furthermore, the sluice gate compartments also trap and accumulate debris upstream, hindering flood drainage and potentially endangering the structural integrity of the dam.

According to Vu Duc Khanh, General Director of Dak Mi Hydropower Joint Stock Company, there is a significant difference in flood water levels between the upstream and downstream areas. The technical specifications of the An Trach dam, with 12 sluice gates and a designed flood discharge capacity of only 1,447 m³/s, mean its ability to discharge floodwaters downstream is much lower than the flood flow on the Vu Gia River. Furthermore, observations during floods show that a large amount of debris flows into the An Trach dam, clogging the sluice gate compartments, limiting flood discharge capacity and threatening the safety of the structure.

A large aquaculture raft drifted in and became stuck in the spillway sections of the An Trach dam during the flood that occurred in mid-June 2025, obstructing flood drainage. Photo: HOANG HIEP

Recently, on October 27th, military forces were mobilized to clear the debris stuck in the An Trach dam, but on October 29th and 30th, a large amount of debris remained at the dam… To minimize damage and flooding in the downstream area, in addition to flood control from hydroelectric reservoirs, the company requests that relevant authorities assess and implement urgent and long-term solutions to increase flood drainage capacity through the An Trach dam in particular and the entire downstream area of ​​the Vu Gia - Thu Bon river system in general.

According to the Department of Agriculture and Environment, the hydraulic automatic gate opening and closing system of the An Trach dam frequently malfunctions during operation; the embankment downstream of the dam is subsiding. At the Ha Thanh dam, the concrete dam, traffic bridge, energy dissipation basin, etc., have deteriorated and cracked; the gate system, pulleys, winches, and lifting cables are rusted... The main dam of the Duy Thanh saltwater intrusion prevention dam has a slight landslide, with a 2cm crack that is not developing further; the dam foundation is slightly seeping. The floating tunnels of the Bau Nit and Thanh Quyt dams are damaged and silted up, rendering the automatic gate opening and closing system inoperable.

Proposal to repair and upgrade 11 irrigation reservoirs.

According to the Department of Agriculture and Environment, in addition to the five aforementioned dams, the city also has 92 irrigation reservoirs (including 24 large reservoirs, 25 medium-sized reservoirs, and 33 small reservoirs) and is currently constructing seven new irrigation reservoirs: Mo O, Ho Khe, Cha Mai, Suoi Tho, Loc Dai, Phuoc Hoa, and Ho Do.

The Duy Thanh saltwater intrusion prevention dam. Photo: HOANG HIEP

According to an inspection and assessment of dam safety during the rainy season by the Department of Agriculture and Environment, 26 reservoir dams experienced seepage; 13 dams suffered landslides and slope failures; 7 spillways had cracks; 6 spillway bodies, tails, and energy dissipators had minor erosion; and 7 spillways showed cracks…

Many dams in irrigation reservoirs are damaged and degraded, requiring continued investment in upgrading and repairing to ensure safe operation during the rainy and flood seasons. In addition, they need to be equipped with infrastructure, management and monitoring equipment, communication systems, and upgraded and repaired access roads.

The Department of Agriculture and Environment has proposed that the City People's Committee allocate funds in the medium-term public investment plan for the period 2026-2030 to repair and upgrade 11 reservoirs in order of priority. These include: Vung Tom, Ba Xa, Ho Quoc, Tra Can, Cay Son, Cuu Kien, O O, Khe Bo, Cay Xoay, Hoc Lach, and Chan Son, with a total estimated cost of approximately 160 billion VND.

The Khe Tan reservoir only has a free-flow spillway and urgently needs investment for repair, upgrading, and the addition of flood control gates to facilitate flood mitigation for downstream areas. Photo: HOANG HIEP

In addition, the Department of Agriculture and Environment has requested the Ministry of Agriculture and Environment and the Department of Water Resources Management and Construction to provide funding for the repair and upgrading of the headworks of five damaged and degraded reservoirs, namely Ho Quoc, Vung Tom, Ba Xa, Tra Can, and Cay Son, to ensure their safety. These five reservoirs should be included in the list of projects requiring upgrading and repair to ensure reservoir safety as soon as possible. Simultaneously, support should be provided for the installation of operational monitoring systems for reservoirs in the city.

During a meeting with the Da Nang City People's Committee on November 4th regarding the management of dikes, dams, and the operation of hydropower plants to regulate floods in the city, representatives from the Department of Water Resources Management and Construction proposed that the city review upstream areas to study the possibility of proposing the construction of reservoirs to serve flood control and reduction and water supply for downstream areas.

For some existing large-capacity irrigation reservoirs with free-flow spillways, especially Khe Tan reservoir (capacity 56 million cubic meters), it is necessary to propose renovation, upgrading, and the addition of regulating sluice gates to help mitigate flooding downstream.

According to Deputy Minister of Agriculture and Environment Nguyen Hoang Hiep, the Ministry will propose to the Government to select a number of large irrigation reservoirs (with a capacity of 20 million cubic meters or more), initially choosing one reservoir to add flood control gates to reduce flooding downstream, as the large capacity of the reservoir is very valuable.

The Ministry of Agriculture and Environment will direct, urge, and coordinate the completion of procedures to soon commence construction of several projects in the downstream area of ​​the Vu Gia - Thu Bon River, especially the construction of water regulation and erosion control works on the Quang Hue River; the construction of a new An Trach dam and the dismantling of the old dam, ensuring flood drainage and water supply for domestic and production purposes in the center of Da Nang city.

Source: https://baodanang.vn/som-cai-tao-ho-dap-phuc-vu-phong-chong-thien-tai-3309406.html