Upstream water levels continue to rise. The Royal Irrigation Department. has increased water discharge. Chao Phraya Dam. Maximum discharge set at no more than 2,500 cubic meters per second, while the Department of Disaster Prevention and Mitigation issues Cell Broadcast alerts to watch areas.
At 21:58 on 30 September 2026, the Facebook page ofthe Royal Irrigation Departmentposted a statement announcing the 7th report on the Chao Phraya River Basin water situation dated 30 September 2026. Following heavy and accumulated rainfall in the upper area, upstream water flow into the Chao Phraya River has continuously increased, necessitating adjustments to water discharge through the Chao Phraya Dam to align with the situation.
Data on 30 September 2026 at 20:00 from station C.2 in Nakhon Sawan Province recorded water flow at 2,565 cubic meters per second, combined with flow from the Sakae Krang River at Ct.19 in Uthai Thani of 554 cubic meters per second. Inflow above the Chao Phraya Dam resulted in a discharge rate of 2,200 cubic meters per second, with the water level above the dam at +17.77 meters above mean sea level.
The Royal Irrigation Department forecasts that on 2 October 2026, flow at C.2 will peak at approximately 3,010 cubic meters per second. When combined with about 700–750 cubic meters per second from tributaries, the upstream volume above the dam is expected to reach roughly 3,600–3,700 cubic meters per second. The irrigation systems on both sides of the river will help absorb about 550–580 cubic meters per second.
In response to this trend, the National Water Resources Committee approved the Royal Irrigation Department's plan to increase discharge through the Chao Phraya Dam, controlling it to not exceed 2,500 cubic meters per second.
Starting at 21:00 on 30 September 2026, the Royal Irrigation Department will gradually increase discharge in steps, from 2,200 to 2,300 cubic meters per second by 02:00 on 1 October 2026 (approximately 20 cubic meters per second per hour), maintaining this rate to minimize downstream impact.
This increase in discharge is expected to raise water levels in low-lying areas outside flood barriers by about 15–30 centimeters. Areas to monitor include Sena, Phak Hai, Bang Ban, Phra Nakhon Si Ayutthaya, Bang Pa-in, and Bang Sai districts in Phra Nakhon Si Ayutthaya Province; Wiset Chai Chan, Pa Mok, Mueang Ang Thong, and Chaiyo districts in Ang Thong Province; In Buri, Phrom Buri, and Mueang Sing Buri districts in Singburi Province; and Sapphaya district in Chainat Province.
The Royal Irrigation Department will utilize irrigation systems on both sides and available areas above the dam to absorb and delay water flow, aiming to minimize downstream discharge as much as necessary. Adjustments will be made based on real-time conditions. If no additional rain occurs, discharge will gradually decrease, with accelerated drainage to the sea via Khlong Lat Pho timed with tidal cycles. Authorities, operators, and residents along the Chao Phraya and Noi rivers are urged to closely monitor the situation.
Meanwhile,the Department of Disaster Prevention and Mitigation (DDPM)has warned that the Chao Phraya Dam will increase discharge to between 2,200 and 2,500 cubic meters per second, causing the Chao Phraya River level to rise by 0.4 to 0.7 meters. This will impact riverside, canal, and low-lying areas in Sena, Phak Hai, Bang Ban, Phra Nakhon Si Ayutthaya, Bang Pa-in, and Bang Sai districts. Residents in riverside and low-lying areas on both banks are advised to move belongings to higher ground, relocate vehicles, and evacuate vulnerable groups. Those needing assistance should contact local village heads or community leaders.
The DDPM, in cooperation with mobile network providers AIS, True, and NT, has sent Cell Broadcast messages warning of rising water levels along the Chao Phraya River in Sena, Phak Hai, Bang Ban, Phra Nakhon Si Ayutthaya, Bang Pa-in, and Bang Sai districts of Phra Nakhon Si Ayutthaya Province.
For emergencies or assistance, people can contact via the LINE application at “DDPM Incident Reporting 1784” by adding Line ID @1784DDPM or call the DDPM emergency hotline 1784, available 24 hours.
Thanks to the Facebook pages of the Royal Irrigation Department and the Department of Disaster Prevention and Mitigation (DDPM).