Bangkok and 10 central provinces put on Chao Phraya flood alert

The Department of Disaster Prevention and Mitigation (DDPM) has coordinated with 10 central provinces and Bangkok to closely monitor water conditions in the Chao Phraya basin.

The Royal Irrigation Department expects an increase in upstream flows at Chao Phraya Dam, requiring downstream releases of 700–1,000 cubic metres per second.

Water levels in low-lying areas outside flood embankments in Phra Nakhon Si Ayutthaya are consequently expected to rise by 0.30–0.40 metres.

Relevant agencies have been told to prepare disaster-response machinery and personnel to assist residents 24 hours a day.

The Central Disaster Management Centre, through the DDPM, issued an alert on Wednesday (November 11, 2026) and coordinated with 10 central provinces: Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Suphan Buri, Phra Nakhon Si Ayutthaya, Lop Buri, Pathum Thani, Nonthaburi and Samut Prakan, as well as Bangkok.

Authorities were instructed to prepare and closely monitor the Chao Phraya basin, particularly low-lying areas outside flood embankments and communities along both banks of the Chao Phraya and Noi rivers.

Upstream flow forecasts and Chao Phraya Dam release plan

Nirat Pongsitthithavorn, DDPM director-general and director of the Central Disaster Management Centre, said the department had been continuously monitoring weather conditions and assessing risk factors.

The Royal Irrigation Department had also issued warning notice No. 8 on water conditions in the Chao Phraya basin, setting out forecasts for the next one to nine days as follows.

Flows at C.2 station in Nakhon Sawan: The maximum flow at the C.2 gauging station in Mueang Nakhon Sawan district, Nakhon Sawan province, is forecast to reach approximately 1,000–1,125 cubic metres per second on November 12.

Tributary flows: An additional flow of approximately 180–200 cubic metres per second is expected from tributaries.

Flows upstream of Chao Phraya Dam: These combined flows are expected to total approximately 1,180–1,325 cubic metres per second upstream of the dam in Chai Nat.

Water management and releases: The Royal Irrigation Department will divert water into irrigation systems on both sides of the river at a rate of 400–500 cubic metres per second.

It will also need to release 700–1,000 cubic metres per second downstream through Chao Phraya Dam.

Areas requiring close monitoring as water rises by 0.30–0.40 metres

Increasing releases from Chao Phraya Dam to 700–1,000 cubic metres per second is expected to raise downstream water levels by approximately 0.30–0.40 metres above current levels, particularly in low-lying areas outside flood embankments in six districts of Phra Nakhon Si Ayutthaya:

• Sena
• Phak Hai
• Bang Ban
• Phra Nakhon Si Ayutthaya
• Bang Pa-in
• Bang Sai

The agencies involved confirmed that the rise remains within manageable limits and has not affected inner neighbourhoods.

However, residents in low-lying areas outside flood embankments in these six districts, as well as those along the Noi River, need to closely monitor water levels because rivers could overflow their banks.

Ten central provinces and Bangkok told to maintain 24-hour readiness

The Central Disaster Management Centre stressed that all 10 central provinces (Uthai Thani, Chai Nat, Sing Buri, Ang Thong, Suphan Buri, Phra Nakhon Si Ayutthaya, Lop Buri, Pathum Thani, Nonthaburi and Samut Prakan) and Bangkok must strictly follow preparedness measures to reduce potential impacts on residents and businesses.

1. Alert relevant groups and riverside businesses

Promptly issue water alerts to relevant agencies, private businesses operating on the Chao Phraya River, waterway users, and residents along both banks of the Chao Phraya and Noi rivers.

Businesses to be notified include contractors building riverbank protection structures, floating restaurant operators and pier operators.

The alerts should enable all these groups to understand water conditions and prepare to protect property and business premises from potential damage.

2. Inspect the strength of flood defences

If conditions appear likely to become severe or water levels rise rapidly, provincial authorities should coordinate with local administrative organisations and irrigation agencies to inspect embankments, flood walls and areas at risk of recurrent flooding.

Defences should be reinforced and leaks sealed in preparation for the incoming water.

3. Prepare machinery and personnel

Ensure materials, equipment, sandbags, water pumps and disaster-response machinery are ready for immediate use.

Deploy teams to monitor water and weather conditions 24 hours a day so they can promptly assist residents in an emergency.

4. Keep the public informed

Provide accurate information to all groups throughout the area to promote public awareness and understanding, using local communication channels including village broadcasting towers, public-address systems, social media and civil defence volunteer networks.

Advice for residents and how to request assistance

The DDPM has issued the following advice for people in areas at risk, particularly low-lying areas outside flood embankments along the Chao Phraya and Noi rivers.

Follow official updates closely: Regularly check water alerts and weather forecasts from government agencies to avoid confusion caused by rumours.

Move belongings to higher ground: Prepare to move household possessions, electrical appliances and vehicles to higher ground so they remain above the water after the expected rise of 0.30–0.40 metres.

Check electrical systems: Beware of electrical leakage in flooded areas and switch off the electricity supply in areas reached by floodwater.

Residents affected by water-related problems or other disasters can report incidents and request help 24 hours a day through the following channels.

• LINE: Add the DDPM incident-reporting account using the LINE ID @1784DDPM.
• Safety hotline: Call 1784, free of charge, 24 hours a day.