Bangkok: The Royal Irrigation Department is gradually increasing water discharge through the Chao Phraya Dam to align with the upstream water levels, diverting water into irrigation systems on the western and eastern sides. The discharge rate is anticipated to range between 500-700 cubic meters per second, with downstream water levels expected to rise but remain below riverbanks.
According to Thai News Agency, Dr. Thanes Somboon, Director of the Water Management and Hydrology Division at the Royal Irrigation Department, has detailed the water situation in the Chao Phraya River basin. Water from upper areas is gradually flowing into regions above the Chao Phraya Dam, with an expectation of increased flow. As of 6:00 AM on August 25th, station C.2 in Mueang Nakhon Sawan District recorded a water flow of 1,006 cubic meters per second, up from 936 cubic meters per second the previous day. Concurrently, the Royal Irrigation Department has been diverting water into irrigation systems on both sides of the dam, totaling 455.23 cubic meters per second, an increase from 406.99 cubic meters per second the day before. The western side is receiving 243.85 cubic meters per second, while the eastern side receives 211.38 cubic meters per second, to effectively manage water resources.
At the Chao Phraya Dam in Chai Nat Province, water discharge downstream has been incrementally increased to 550 cubic meters per second from 450 cubic meters per second the previous day. The aim is to maintain the upstream water level within appropriate limits and minimize the impact on downstream areas. The water flow through the Chao Phraya Dam is expected to increase to approximately 500-700 cubic meters per second, causing a rise in water levels downstream 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. The levels are expected to increase by about 1-1.5 meters but will remain below the riverbanks.
The Meteorological Department forecasts heavy rainfall in parts of Thailand from August 24-30 due to a strong southwest monsoon and a monsoon trough connected to Tropical Storm "Narra" in the Gulf of Tonkin. Although the storm will not impact Thailand directly, the monsoon trough will bring rain. From August 27-30, upper Thailand will experience increased rainfall, with particularly heavy rain expected in the North and Northeast, and very heavy rain in some areas west of the Central region. The National Environment Board has identified regions at risk of accumulated rainfall exceeding 150 millimeters over the three days from August 24-26, including districts in Tak, Kanchanaburi, and Trat provinces.
Regarding the main dams in the Chao Phraya River basin, Bhumibol Dam holds 7,526 million cubic meters of water at 56% capacity, Sirikit Dam has 6,718 million cubic meters at 71% capacity, Kwaenoi Bamrungdan Dam holds 339 million cubic meters at 36% capacity, and Pa Sak Chonlasit Dam has 300 million cubic meters at 30% capacity.
The Royal Irrigation Department has instructed regional agencies to closely monitor water levels in the upper Chao Phraya River basin and prepare machinery, equipment, and personnel to provide timely assistance to the public. The department issued Warning Notice No. 7 on August 24, 2026, informing governors of the basin's seven provinces and relevant agencies to disseminate information to residents along the Chao Phraya River, urging them to monitor the situation and follow official updates closely. The RID emphasizes managing water resources to prioritize public impact.