Heavy rain in Myanmar raises Sai River, putting Thailand’s Mae Sai on alert

Mae Sai, a border district in Thailand’s Chiang Rai province, has been on high alert since water levels in the Sai River increased following heavy rainfall in Myanmar. Although the water level remains below the temporary flood barriers, many residents and business operators were seen placing large sandbags and other items around their properties as a precaution against possible flooding. The water level in the Sai River at the First Thai-Myanmar Friendship Bridge had risen close to the underside of the bridge by 6am on 31 July, carrying large amounts of driftwood and debris downstream. However, the water was still well below the flood protection embankments. According to the Hydro-Informatics Institute, rainfall at the Jotada monitoring station in Myanmar’s upstream area reached 80mm, raising concerns that more water would flow into Mae Sai. Mae Sai District Chief Warayut Khombun said officials have been inspecting the entire flood defence system and found water seeping through some sections of the temporary barriers, particularly near buildings awaiting demolition along Koh Sai Road beside the Sai River. Workers have been reinforcing the weak points. Mae Sai Mayor Anucha Yodchiangkham said authorities are closely monitoring the situation following the heavy rainfall in the river’s upper catchment area. Water from the Jotada station in Myanmar takes about five hours to reach Mae Sai. Officials said the district will remain on alert, but if no additional rain falls upstream, water levels are expected to gradually fall and the situation should ease.