MAE constructs scenario to secure water resources in Mekong Delta

The Ministry of Agriculture and Environment (MAE) released the Water Resources Scenario in the 2025–2026 dry season in the Mekong River Basin under Decision No. 4815/QD-BNNMT. The scenario is constructed based on a comprehensive analysis of current conditions, meteorological and hydrological forecasts, water resource dynamics, extraction demands, and requirements for ensuring water security in the Mekong Delta. The assessment period runs from November 2025 to May 2026.

Potential risks of water shortages

Based on the current status of water resources, combined with meteorological and hydrological forecasts and extraction demands across the basin, the specialized agency has given an integrated assessment of the Mekong River's water supply capacity in the 2025–2026 dry season and clarified potential risks that may arise to serve management and ensure water security and food security.

Regarding upstream water sources, the scenario forecasts that flows from the Tonle Sap Lake will continue to serve as an essential replenishment for downstream areas from November 2025 to May 2026. Total volume of water is expected to reach around 47 billion m³, 20–21% higher than the multi-year average and the same period of 2024–2025. At the Kratie station, flow rate is also projected at 100–112 billion m³, up 10–25%. These positive signals show that water resources for the Mekong Delta during the 2025–2026 dry season will generally be more favorable than last year.

Within the Mekong Delta, total water intake through Tan Chau and Chau Doc is estimated at 150–170 billion m³, up 10–25% from the multi-year average. In addition, the ability to have off-season rain during the dry period will help improve local water resources for production and domestic use.

As for groundwater, forecasts indicate that from November 2025 to May 2026, supplies will remain basically stable and sufficient to meet demand. However, the level of adequacy varies across regions. In coastal provinces from Vinh Long to Ca Mau, several groundwater extraction works are forecast to have dynamic water levels approaching the 35 m threshold, including water supply stations in Bac Lieu and several inner-city wards. Although total extraction capacity can still remain at around 33,900 m³/day-night, these works require close monitoring. Other wells maintain dynamic water levels of 25–30 m, ensuring extraction of more than 43,900 m³/day-night.

In Can Tho, Dong Thap, and Tay Ninh, some constructions also have dynamic water levels approaching the allowable threshold, including the Binh Anh and Tan An water plants and certain seafood enterprise extraction facilities. Total extraction remains at roughly 18,200 m³/day-night. Most of the remaining works still ensure stable extraction.

Regarding saltwater intrusion, severity is projected to be milder than in the 2024–2025 dry season thanks to better-performing salinity control structures. In Tay Ninh, saltwater may penetrate as far as Tam Vu, Vinh Cong, and Tan Tru along the Vam Co Tay River, and to Binh Duc and Ben Luc along the Vam Co Dong River. In Dong Thap, salinity could reach My Phong (Cu Tieu River) and My Tho (Cua Dai River). In Vinh Long, where the salinity control system remains incomplete, saltwater may intrude deeply into communes along the Ham Luong, Co Chien, and Hau rivers. Can Tho is relatively well-protected thanks to the Cai Lon–Cai Be sluice system. An Giang remains shielded by coastal structures along the West Sea, while Ca Mau continues to face saltwater intrusion via the Ong Doc and Ganh Hao Rivers.

A synthesis of upstream flow, surface water, groundwater, and saltwater intrusion factors indicates that water resources in the 2025–2026 dry season in the Mekong River Basin are assessed to be in a normal state, adequately meeting demands for domestic water supply, social welfare, economic production, and environmental protection. However, localized shortages may still arise in several downstream communes of Tay Ninh, Dong Thap, Vinh Long, and Ca Mau, primarily due to saltwater intrusion and unsynchronized irrigation infrastructure.

Planning for appropriate water extraction and use under the scenario

To reduce the risk of localized water shortages, prevent saltwater intrusion, and prioritize domestic water supply, the MAE has proposed several key measures for the Mekong River Basin.

First, the Ministry of Construction and provincial People’s Committees are required to develop water extraction and usage plans based on actual demands of each sector and locality, following principles of efficiency, loss reduction, and contingency for peak months of saltwater intrusion. Provincial People’s Committees should update meteorological and hydrological forecasts, review and upgrade irrigation systems to improve storage capacity and flow circulation, prevent stagnation and pollution, and establish lists of reservoirs, ponds, lagoons, and zones where groundwater extraction is restricted or prohibited.

The MAE's agencies will coordinate in implementing water resources scenarios, regulating and allocating water during periods of widespread shortages, and providing periodic reports on the current status of water resources. Specialized departments will provide guidance on adjusting cropping schedules, crop and livestock structures, and aquaculture activities in line with water conditions, while also monitoring, forecasting, and issuing warnings for areas at risk of water shortages or saltwater intrusion.

For areas facing risks of localized water shortages, provinces such as Tay Ninh, Dong Thap, Vinh Long, and Ca Mau should develop response plans for each shortage level; adjust cropping calendars; combine the use of surface water, groundwater, and rainwater; enhance water storage; and invest in the construction of water regulating and storage works, especially in water-scarce zones and communities of ethnic minorities.

To enhance water-use efficiency, localities need to ensure rational water extraction, provide cultivation guidance based on technical recommendations, and operate irrigation systems flexibly according to water conditions. The Ministry of Construction and provincial People's Committees should work together to upgrade water plants, expand water supply networks, and implement technologies for saline and brackish water treatment and wastewater reuse to ensure domestic water security.

Regarding groundwater, provinces need to control extraction at centralized works and small wells, study artificial groundwater recharge, and monitor areas at risk of land subsidence, pollution, or salinization to protect water resources sustainably.

If implemented synchronously, these measures will help ensure water security, minimize localized water shortages, prevent saltwater intrusion, and maintain stable and safe water supplies for domestic use, production, and economic development in the Mekong River Basin.