Rising Tensions In Chiang Rai As New Flood Threats Loom Over Mae Sai

CHIANG RAI – High-ranking officials and disaster experts gathered in Chiang Rai on May 7, 2026, to issue an urgent warning regarding the Mae Sai River, stating that the border region faces an exceptionally high risk of severe flooding this year.

Chiang Rai Governor Chuphong Pongchai, alongside environmental scholars, revealed that changes in local infrastructure and a lack of cooperation from Myanmar have created a “highly sensitive” situation.

With the rainy season approaching, experts warn that even moderate rainfall of just 40 millimeters could trigger significant overflows, threatening the lives and property of residents in Mae Sai and the neighboring Tachileik district.

The current situation is far more dangerous than in previous years due to a significant imbalance in flood defenses. While Thai authorities have worked to dredge parts of the Ruak River and reinforce embankments, the Myanmar side has taken a different approach.

According to reports from the Chiang Rai Provincial Disaster Prevention and Mitigation Office, Myanmar has constructed flood walls that are nearly one meter higher than those on the Thai side.

This height difference acts as a funnel, pushing rising waters toward the Thai bank with increased speed and force. Furthermore, Myanmar has yet to fulfill its agreement to dredge a critical 12.8-kilometer stretch of the Sai River. This neglect has left the riverbed shallow, significantly reducing its capacity to handle the heavy runoff typical of the monsoon season.

Rising Tensions in Chiang Rai

Expert Warnings: Why 2026 is Different

Associate Professor Dr. Seri Supparatit, a leading expert on climate change and disaster management, highlighted several factors that make this year particularly volatile:

Environmental Shifts: New construction on both sides of the border has altered the natural flow of the river.
Faster Water Runoff: Water from upstream stations like Ban Jota-da now reaches Mae Sai much faster than the historical four-hour window.
Personnel Changes: A shift in the officials responsible for managing these borders means a loss of institutional memory during a critical time.

Dr. Chuchoke Aryupong from Chiang Mai University’s Center of Excellence in Natural Disaster Management (CENDiM) added that the Friendship Bridge 1 is a major point of concern. The gap beneath the bridge has narrowed to just 1 to 1.5 meters due to sediment buildup. If water levels hit critical thresholds, the bridge could act as a dam, catching debris and forcing water into the surrounding urban areas.

In response to these threats, Governor Chuphong has ordered an immediate mobilization of resources starting May 8, 2026. The provincial government has allocated a 39-million-baht budget for urgent embankment repairs, which are expected to be completed by the end of the month.

The military, including the 37th Military District and the Department of Military Engineers, will be stationed at key “weak points” along the river. Heavy machinery, such as backhoes from the Department of Disaster Prevention and Mitigation (DDPM) Region 15, will be positioned at the Friendship Bridge to clear branches and trash that could block the flow.

Rising Tensions in Chiang Rai

Safety Measures for Residents

The Mae Sai District Chief, Warayut Khombun, noted that the district is refining its early warning system. Residents are advised to stay alert and follow these safety protocols:

Monitor Rainfall: If rainfall at the Ban Jota-da station exceeds 50mm, the warning level will be raised.
Early Evacuation: Given the faster water flow, the evacuation window has been shortened. Families should be ready to move within 2 to 3 hours of a warning.
Safe Zones: Designated shelters include local temples, the district auditorium, and elevated parking structures.

Thai officials are continuing to coordinate with their Myanmar counterparts through the Thailand-Myanmar Border Committee to push for the promised dredging of the river. However, until that work is completed, the focus remains on local fortification and rapid emergency response to prevent a repeat of the catastrophic floods seen in 2024.