MAE: El Nino may trigger water shortages in 2026-2027

In April, the Ministry of Agriculture and Environment sent Official Dispatch No. 3764/BNNMT-KTTV to the Head of the National Civil Defense Steering Committee to provide information on the El Nino phenomenon and an early assessment of the potential risk of water shortages.

According to observational data and climate forecast models, the ENSO system is transitioning from La Nina to a neutral phase and is highly likely to shift to El Nino between June and August 2026, with a probability of 80 - 90%. It is then expected to continue developing and may reach moderate to strong intensity by the end of 2026. Notably, the possibility of a very strong El Nino event (with a probability of about 20 - 25%) during October and December 2026 cannot be ruled out, and it may persist into 2027.

Although long-term forecast models still involve certain uncertainties, in order to support timely direction and management in disaster prevention and control as well as socio-economic development, the Ministry of Agriculture and Environment has issued an early assessment of the El Nino situation and water resources nationwide.

In Viet Nam, hot and dry conditions have appeared early since the beginning of 2026, with heatwaves intensifying sooner than the multi-year average. Rainfall from the start of the year to mid-April has generally been 10 - 40% lower than the long-term average nationwide; river flows and water levels in many basins have dropped to the lowest levels observed for the same period in the monitoring record. These are early warning signs of potential water shortages from the very start of the season.

The average storage of irrigation reservoirs in the Northern region currently stands at 59.3% of design capacity; provinces from Thanh Hoa to Hue are at around 71%; and those from Da Nang to Khanh Hoa and Lam Dong are also at approximately 71% of design capacity.

Regarding major hydropower reservoirs, as of April 15, storage levels in large reservoirs in the North range from 60% to 95% of design capacity, equivalent to 22.3 billion cubic meters, about 1.1 billion cubic meters higher than the average of the past five years. Reservoirs in the North Central region are at 60 - 96% of capacity; the South Central region at 55 - 92%; the Central Highlands at 52 - 95%; and the Dong Nai River basin at 48 - 99%.

In the coming period, if El Nino develops as forecast, average temperatures nationwide are expected to be higher than normal, with more frequent and more intense heatwaves compared to 2025. Rainfall is likely to be deficient during the dry months of 2026, particularly from late 2026 to early 2027, with a widespread reduction of 25-50%. The rainy season may also end earlier than usual.

According to the Ministry of Agriculture and Environment, water resources in river basins are likely to continue declining. In major reservoirs, especially in the Da River system, total inflows from May to July 2026 may be 10 - 25% below the long-term average, posing a high risk of water shortages due to reduced transboundary inflows combined with domestic rainfall deficits, potentially affecting downstream water supply and energy security.

There is a high risk of drought and saltwater intrusion, particularly in the South Central region, the Central Highlands, and the Mekong Delta during the 2026 - 2027 dry season. Water shortages may also occur on a wide scale in the early months of 2027.

Notably, during El Nino periods, although total rainfall decreases, localized heavy rains and short-duration extreme rainfall events may still occur, causing flash floods, landslides, and urban flooding. Storms and tropical depressions over the East Sea tend to be fewer than average, but strong storms with complex, unpredictable tracks may still occur and cause significant impacts in a short time.

In the coming time, the Ministry of Agriculture and Environment will continue to direct forecasting units to closely monitor meteorological and hydrological developments, especially ENSO conditions, water resources, and hazardous weather phenomena; and to promptly update and issue forecasts and warnings to support the Government, ministries, sectors, and localities in their direction and management efforts.