The Deputy Secretary-General of the National Water Resources Office (NWRO) revealed that northern water volumes have decreased, with efforts underway to expedite drainage from all water basins into the Gulf of Thailand in preparation for rainfall from 11 to 13 October. Meanwhile, the Meteorological Department has issued a warning to monitor a low-pressure trough crossing central Thailand and Bangkok on 11 October.
At 11:10 a.m. on 2 October 2026 at the Government House, Mr. Paitoon Kengkanchang, Deputy Secretary-General of the National Water Resources Office (NWRO), discussed the water situation. He noted concerns about the northern water mass flowing into the Chao Phraya basin. Currently, the main dams in the basin include Bhumibol Dam at 70% capacity, Sirikit Dam at 80%, and Kwae Noi Bamrung Dan Dam at 70-80%. Only Pasak Cholasit Dam exceeds 100% capacity but still has a buffer of 6 billion cubic meters, unlike the 2011 situation. Water flow in the Ping and Sakae Krang rivers is significantly decreasing by over 500 cubic meters per second. He confirmed that northern water volume is decreasing, with outflow maintained at 2,500 cubic meters per second. This rate can be sustained for 5-6 days to accommodate rainfall expected from 11 to 13 October.
Mr. Paitoon stated that although Pasak Cholasit Dam is over capacity, water is currently being released at 400 cubic meters per second into the Pasak River, with downstream areas in Saraburi Province unaffected. Combined flow with the Chainat-Pasak canal is about 540 cubic meters per second, joining the Chao Phraya River’s discharge of 2,500 cubic meters per second. Recent observations show this water will merge at Bang Pa-in and Bang Sai districts in Phra Nakhon Si Ayutthaya before flowing into Pathum Thani and Nonthaburi at approximately 2,100 cubic meters per second. The water also flows toward Phak Hai and Chao Chet subdistrict in Sena district, then onward to Suphanburi Province.
Mr. Paitoon added that riverbank water levels in Nonthaburi remain 1.2 meters below the embankment or flood walls, while Pathum Thani is 0.57 meters below, and Bangkok is 1.2 meters below, allowing continued drainage. Therefore, the Chao Phraya water situation, especially the northern water mass causing concern, is not worrisome and tends to decrease. However, rainfall between 11-13 October must be monitored. If drainage continues at 2,500 cubic meters per second, there will be sufficient reservoir capacity, minimizing impact on Bangkok and surrounding provinces. Nonetheless, some areas in eight districts of Phra Nakhon Si Ayutthaya, such as Sena and Phak Hai, may be affected as they lie outside flood barriers. The provincial governor has deployed military forces to assist and evacuate residents due to the planned drainage at 2,500 cubic meters per second for 5-6 days.
The NWRO Deputy Secretary-General acknowledged that the Tha Chin River basin currently has substantial water volumes. At the downstream Pho Phraya watergate in Suphanburi Province, water release levels are managed to avoid significant impact. Previously, rainfall in five districts of Kanchanaburi Province flowed into the Tha Chin River near Song Phi Nong District in Suphanburi. Therefore, water management at the boundary between Suphanburi and Nakhon Pathom provinces has been effectively handled.
The Deputy Secretary-General further explained that Bangkok’s water management on the Chao Phraya side can pump over 70 million cubic meters daily, or roughly 800 cubic meters per second, through tunnels and canals. However, drainage on the eastern side toward Chachoengsao and Samut Prakan provinces remains limited. Orders have been given to the Royal Thai Army and Ministry of Defense to increase pumping equipment at points where drainage is efficient.
“Regarding northern water, people can be reassured, but continuous monitoring of the Chao Phraya basin is necessary. Flooding may occur upstream of the Chao Phraya Dam, such as in Nakhon Sawan, Sawang Arom District, and Kwae Tak Daet River in Uthai Thani. The government is providing full assistance to affected residents,” said Mr. Paitoon.
The Deputy Secretary-General noted that on 2 October, the Bang Pakong River basin recorded a new high water level at 4.98 meters, 11 centimeters above the 2013 record. Water release is controlled by Khun Dan Prakan Chon Dam, which allows regulation. The Royal Irrigation Department will continue controlled releases to maintain buffer capacity. From 11 to 13 October, water releases will be reduced to prevent downstream impact, though areas such as Bang Nam Priao District in Chachoengsao, Ongkharak and Pak Phli districts in Nakhon Nayok, and Ban Sang District in Prachinburi face flooding in some spots. The government and Navy have deployed boats to push water along the Bang Pakong River.
Mr. Paitoon mentioned that smaller basins, such as in Rayong Province—including Ban Khai, parts of Mueang Rayong, and Mueang Chanthaburi districts—may experience heavy rain on 11 October according to the Meteorological Department. Eastern provinces are preparing accordingly. In the Mae Klong basin, Vajiralongkorn Dam still has about 120 million cubic meters of available capacity, releasing about 40 million cubic meters per day, which can last about 50 days. Inflows are about 50 million cubic meters per day, with an additional 40 million expected on 3 October. Outflow and inflow are balanced, but releases will be accelerated to prepare for rainfall on 11-13 October. Srinakarin Dam has about 700 million cubic meters capacity remaining for rains expected on 6 and 11-13 October. Mae Klong Dam, at the downstream end of Vajiralongkorn and Srinakarin dams, releases over 1,800 cubic meters per second. It is expected that within a week, releases will reduce below 1,000 cubic meters per second near Ban Pong, Photharam, Mueang Ratchaburi, Amphawa, and Bang Khonthi districts in Samut Songkhram, where water levels will decline.
Mr. Paitoon also said that Kaeng Krachan Dam in the Phetchaburi basin currently has an inflow of 11-13 million cubic meters and outflow of 10 million cubic meters, which remains manageable. Therefore, Phetchaburi Province remains safe from expected flooding.
Nonetheless, preparations must continue for 6 and 11-13 October, requiring ongoing water releases. He emphasized that northern water volumes are trending downward and remain safe, including in Pathum Thani, Nonthaburi, Bangkok, and Samut Prakan provinces, although some localized flooding may occur.
Mr. Fata Marsatavee, a specialist in meteorological forecasting system development, stated that starting 4 October, rainfall will increase beginning in northeastern Thailand, moving into the Chao Phraya basin and Bangkok on 5 October, and western areas, especially Kanchanaburi Province, on 6-7 October. After 7 October, rain will decrease to isolated showers in the north. However, on 11 October, vigilance is required for a low-pressure trough over central Thailand and Bangkok. The Meteorological Department, NWRO, and relevant agencies will closely monitor and prepare for the situation.
