Seven Thai provinces warned as Chao Phraya Dam discharge set to rise
Regional Irrigation Office 12 says upstream runoff is raising water above Chao Phraya Dam, with discharge expected at 500–700 cubic metres per second.
- Seven provinces in the Chao Phraya River Basin have been warned of rising water levels by the Regional Irrigation Office 12.
- The warning is due to increased upstream runoff, which will require the Chao Phraya Dam to increase its water discharge rate to between 500 and 700 cubic metres per second.
- The increased discharge is expected to raise downstream river levels by 1 to 1.50 metres, though the
Regional Irrigation Office 12 has warned seven provinces in the Chao Phraya River Basin to prepare for rising water levels as runoff from upstream areas continues to flow into the area above Chao Phraya Dam at an increasing rate.
Songkran Chalosrithong, director of Regional Irrigation Office 12, alerted the governors of Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Suphan Buri, Phra Nakhon Si Ayutthaya and Lop Buri to the latest “water situation and water management in the Chao Phraya River Basin” in a letter dated Sunday (24 May 2026).
The office said the latest reading at water gauging station C.2 in Mueang Nakhon Sawan district, Nakhon Sawan province, showed water flowing through the monitoring point at 1,058 cubic metres per second.
The water mass has since flowed into the Chao Phraya Dam, causing the upstream water level to rise.
The dam is required to keep its upstream water level within the control threshold of no more than +16.60 metres above mean sea level, or MSL.
The volume of water flowing through Chao Phraya Dam is expected to trend higher, in the range of 500–700 cubic metres per second.
Any increase in discharge within that range would push up water levels in riverside areas downstream of the dam, from Sapphaya district in Chai Nat province to Ban Krathum and Hua Wiang subdistricts in Sena district, and Tha Din Daeng subdistrict in Phak Hai district, Phra Nakhon Si Ayutthaya province.
Water levels in those areas are expected to rise by about 1–1.50 metres, although the office said the higher levels would remain below the riverbanks.
Regional Irrigation Office 12 said it would control discharge through Chao Phraya Dam within the expected range by managing water as efficiently as possible, in order to avoid impacts on low-lying areas and local agricultural land.
Chao Phraya Dam in Sapphaya district, Chai Nat province, had an upstream water level of 16.56 metres MSL and a downstream water level of 8.60 metres MSL as of Sunday (24 May 2026).
The water level remained 7.74 metres below the riverbank, while the dam was maintaining its discharge rate at 500 cubic metres per second.
The office said it would issue a further announcement if runoff volumes increase and the flow through Chao Phraya Dam exceeds 700 cubic metres per second.
Relevant agencies, companies and businesses operating on the Chao Phraya River have been urged to prepare and reduce possible losses.
The warning covers activities such as embankment construction works, floating restaurants and fish farmers using cages.
People living along both banks of the Chao Phraya River and the Noi River have also been asked to “stay alert and closely monitor the water situation” during this period.
