The Royal Irrigation Department (RID) is preparing to gradually increase the water discharge rate through the Chao Phraya Dam to between 1,000 and 1,300m3/s to accommodate northern run-offs following torrential downpours across several provinces.
The increased discharge is expected to raise water levels downstream by 0.50 to 1.50 metres.
Wittaya Kaewmee, director general of the RID, disclosed yesterday, after chairing a water situation monitoring and assessment meeting, that the department is closely monitoring weather conditions, rainfall volume and the overall water situation in the Chao Phraya River Basin.
“Water management plans are being adjusted accordingly to cope with northern run-offs and minimise the impact on local residents,” he said.
Currently, the C.2 water gauging station in Nakhon Sawan province reported a flow rate of 1,377m3/s, showing an upward trend from the previous day.
In response, the RID is stepping up the discharge rate below the Chao Phraya Dam.
Concurrently, water is being diverted into irrigation systems on both the eastern and western banks to reduce the volume flowing further downstream.
The discharge adjustment is anticipated to cause river levels downstream to rise by roughly 0.50 to 1.50 metres from current levels, particularly in low-lying areas outside flood embankments in Sena, Phak Hai, Bang Ban, Phra Nakhon Si Ayutthaya, Bang Pa-in and Bang Sai districts of Phra Nakhon Si Ayutthaya province.
These water levels, however, are not expected to affect communities located inside the flood walls.
According to the RID, the surge in water levels stems from heavy to very heavy rainfall across northern regions on September 19 and 20, where several areas recorded over 100mm of rain.
Recent measurements show Kamphaeng Phet receiving 146mm of rainfall and Phitsanulok recording 136mm, causing runoff in major tributaries to continuously rise.
Meanwhile, the four main reservoirs in the Chao Phraya River Basin, including those behind the Bhumibol, Sirikit, Kwae Noi Bamrung Daen and Pasak Jolasid dams, currently hold a combined 68% of their total capacity, with remaining storage capacity for approximately 7 billion cubic metres of water.
The RID has notified the governors of 11 provinces in the Chao Phraya Basin to prepare for the additional water discharge.
Residents living along the riverbanks and in low-lying areas are urged to monitor official announcements closely.
The department added that, should further increases in discharge become necessary, timely warnings will be issued to vulnerable communities.
