Cross-Border Flooding Hits Mae Sai and Tachilek After Sai River Overflows
CHIANG RAI, Thailand – Heavy rainfall upstream in Myanmar caused the Sai River to overflow its banks, resulting in significant flooding across border areas in Thailand’s Mae Sai district and Myanmar’s Tachilek town. The floodwaters impacted both local communities and businesses, exposing vulnerabilities in the region’s infrastructure during the early stages of a joint river management project.
On Monday, runoff from persistent rain in Myanmar surged into the Sai River, flooding low-lying Thai communities such as Koh Sai and Mai Lung Khon in Mae Sai, as well as bustling markets in Tachilek including Sai Lom Joy and Ta Lor.
The flooding occurred while Thailand and Myanmar are undertaking a joint riverbank protection and dredging project along the Sai and Ruak rivers. The 20-kilometre-long initiative, which spans both nations, aims to strengthen flood defences and improve water flow. However, the temporary removal of old floodwalls and sandbags for construction may have left communities exposed to this unexpected inundation.
Despite efforts to contain the water using temporary flood walls, strong currents caused them to collapse, leading to further inundation of residential areas and market zones. Authorities responded swiftly to install additional sandbags and assist affected residents.
The incident highlights the need for closer cross-border coordination and readiness during transitional phases of infrastructure projects. Both Thai and Myanmar officials have pledged to reinforce protective measures while continuing with long-term solutions.
