The Royal Irrigation Department (RID) has increased the water discharge rate through the Mae Klong Dam to 2,000m3/s since 1pm today, raising river levels by up to three metres downstream and triggering safety warnings across four western and coastal provinces.
Residents along the riverbanks and in low-lying areas in Kanchanaburi, Ratchaburi, Samut Songkhram and Samut Sakhon have been urged to move their belongings to higher ground, monitor vulnerable groups, such as bedridden patients and the elderly, and prepare evacuation plans.
Witthaya Kaewmee, director general of the RID, said that the department is monitoring the Mae Klong River Basin closely, following continuous increases in water volume flowing from the Khwae Noi and Khwae Yai rivers.
Earlier on Tuesday, Irrigation Office 13 sent an urgent letter to the governors of the four affected provinces.
Telemetry data from Station K.37 in Ban Wang Yen, Muang district, Kanchanaburi, recorded a flow rate of 1,895m3/s in the Khwae Noi River at 10am, with an upward trajectory.
The heavy inflows are driven by shifting rainfall patterns over northern and western central regions, particularly Kanchanaburi and Ratchaburi, where heavy rain and accumulated rainfall remain a threat.
Upstream, the reservoir behind the Vajiralongkorn Dam in Kanchanaburi reached 8.484 billion cubic metres of water, or 96% of its total capacity, on Monday. Continuous inflows have forced the Electricity Generating Authority of Thailand (EGAT) to step up discharge operations from 15 million cubic metres per day to 30 million cubic metres today.
EGAT plans to scale up the release to 42 million cubic metres daily from September 30 to October 4.
Water released through the Vajiralongkorn Dam flows down the Khwae Noi River before merging with the Khwae Yai River in Kanchanaburi to form the Mae Klong River, prompting ongoing assessments of incoming water volumes at the Mae Klong Dam.
The RID has called on local government agencies, local administrative organisations and residents along the riverfront to stay alert for sudden flash flooding and follow official updates closely.
