Hundreds of damaged irrigation reservoirs need repairing

The forum discussing the state of the nation's dams and reservoirs opened yesterday in Hà Nội. VNS Photo Tố Như

HÀ NỘI – There are about 340 reservoirs across the country which are severely damaged and lack funding for repair and upgrades, according to the Department of Water Resources.

According to statistics from the department, the country currently has 7,315 dams and irrigation reservoirs with a total storage capacity of approximately 15.2 billion cu.m.

Irrigation reservoirs shoulder many critical responsibilities, such as supplying water for agriculture, industry and domestic use, combined with flood control and other purposes, including hydropower, providing spaces for solar power development, aquaculture and tourism development.

However, Việt Nam's system of dams and reservoirs is facing numerous challenges. Unusual rainfall patterns, flash floods due to climate change and the degradation of many structures pose significant safety risks.

At the forum 'Improving Information Efficiency, Warning, and Ensuring Safe Operations of Dams and Reservoirs in the New Context' yesterday in Hà Nội, the director of the Institute of Water Resources Planning, Đỗ Văn Thành, said there were numerous ongoing issues affecting the safety of irrigation dams and reservoirs.

“As of pre-flood 2024 statistics, around 340 reservoirs are severely damaged of which there are 43 large reservoirs, 95 medium-sized reservoirs and 202 small reservoirs, which have yet to receive funding for repair or upgrades,” Thành said.

“Many dams and reservoirs, built over 30 years ago, are experiencing degradation, including sedimentation.

“Numerous reservoirs, now serving multiple purposes, require a re-evaluation of their missions and design parameters. Boundary markers for project protection areas remain inadequately installed,” he said.

According to the expert, some large reservoirs have flood maps while their downstream flood drainage capacity has not been fully assessed.

Many small reservoirs lack safety assurance and downstream flood prevention plans.

The downstream flood drainage corridors of some large reservoirs have been encroached upon, narrowing waterways and hampering design flood discharge, which causes flooding in downstream areas during flood discharges.

Furthermore, forecasting and warning capabilities for rainfall, floods, and incoming water to reservoirs remain limited. Management, operation and safety assurance for dams have not been fully modernised.

“Managing and operating irrigation reservoirs faces many challenges due to climate change, which has increased the frequency and intensity of rain and floods.

“Most irrigation reservoirs were built before 2000 when designs did not fully assess downstream flood drainage capabilities. Additionally, in many regions, water demand for production now exceeds the reservoirs’ capacity to supply,” he added.

In light of these challenges, the expert proposed strengthening institutions and policies for the management, investment and protection of reservoirs and dams to optimise their functions and ensure the safety of the structures and downstream areas.

Detailed research should be conducted on reservoir and dam proposals outlined in the national planning schemes and operational procedures and safety plans should be developed and updated, especially for small and medium-sized reservoirs and dams.

Flexible and rational use of the volume above the normal water level should be considered to enhance water regulation and flood prevention. Research into using semi-submerged areas for effective exploitation should also be conducted.

Technological advancements should be applied to planning, design, construction and operational processes. Diverse funding sources for investment, exploitation and protection of irrigation reservoirs and dams should be mobilised.

At the forum, experts and managers emphasised that a key priority was enhancing information, warning and forecasting capabilities, while building monitoring systems in upstream regions and reservoirs to support hydrological analysis.

Furthermore, developing support tools, applying technical advancements, and using artificial intelligence (AI) in decision-making for the safe operation of dams and reservoirs was essential for proactive forecasting and warning.

This would also enable suitable flood regulation and discharge scenarios to ensure downstream safety.

Deputy director of the Department of Water Resources, Lương Văn Anh, said: “In addition to improving the institutional and policy framework for managing and operating irrigation reservoirs, it is necessary to modernise management systems.

“Investment in repairing and upgrading irrigation reservoirs should continue. Solutions to ensure downstream safety and maximise the multi-purpose use of reservoirs must also be reviewed and proposed,” Anh said.

The forum was co-organised by Việt Nam Agriculture Newspaper, the Department of Water Resources, the Institute of Water Resources Planning and the Việt Nam National Committee on Large Dams and Water Resource Development.