Mekong River rising as Thailand braces for floods, landslides and heavy rain from July 6-12 

Thailand’s Office of the National Water Resources (ONWR) on Saturday issued Warning No. 10/2025, urging the public to brace for widespread flash floods, runoff, and landslides across the country due to heavy to very heavy rainfall forecast from July 6–12. Authorities are also closely monitoring the rising water levels of the Mekong River, which may aggravate flood risks in many provinces.

The ONWR is working closely with the Meteorological Department, the Department of Mineral Resources, the Royal Irrigation Department, and the Department of Disaster Prevention and Mitigation to assess risks and issue advance warnings for vulnerable areas. Residents are urged to remain vigilant and prepared at all times.

Flood and Landslide Risk Areas Identified

Based on current forecasts and hydrological assessments, several high-risk areas across all regions of Thailand have been identified:

Northern Region

• Chiang Rai: Mueang Chiang Rai, Mae Sai, Phaya Mengrai, Wiang Chai, Thoeng, Chiang Khong, Wiang Kaen, Chiang Saen
• Nan: Mueang Nan, Bo Kluea, Pua, Thung Chang, Phu Phiang, Song Khwae, Chaloem Phra Kiat, Chiang Klang, Tha Wang Pha, Wiang Sa
• Phayao: Mueang Phayao, Dok Khamtai, Pong, Chiang Kham, Chiang Muan
• Tak: Tha Song Yang

Northeastern Region

• Loei: Mueang Loei, Na Duang, Dan Sai, Na Haeo, Pak Chom
• Nong Khai: Mueang Nong Khai, Phon Phisai, Rattanawapi
• Bueng Kan: Mueang Bueng Kan, Seka, Bung Khla, Pak Khat
• Udon Thani: Mueang Udon Thani, Wang Sam Mo, Phen, Sang Khom, Ban Dung, Nong Han
• Sakon Nakhon: Akat Amnuai, Sawang Daen Din
• Nakhon Phanom: Si Songkhram, Na Thom
• Yasothon: Mueang Yasothon, Maha Chana Chai
• Ubon Ratchathani: Khong Chiam, Sirindhorn, Phibun Mangsahan, Si Mueang Mai

Eastern Region

• Chonburi: Bang Lamung, Si Racha
• Rayong: Mueang Rayong, Ban Khai, Pluak Daeng, Nikhom Phatthana
• Chanthaburi: Mueang Chanthaburi, Khlung, Tha Mai, Na Yai Am, Makham, Laem Sing
• Trat: Mueang Trat, Khao Saming, Khlong Yai, Bo Rai

Southern Region

• Ranong: Mueang Ranong, Suk Samran, Kapoe, La-un, Kraburi
• Phang Nga: Kuraburi, Takua Pa, Kapong, Thai Mueang
• Phuket: Mueang Phuket, Kathu, Thalang
• Surat Thani: Chaiya, Ban Ta Khun, Ban Na San

Authorities have urged the public to monitor official weather updates and take precautionary measures, particularly those living near rivers, foothills, or flood-prone zones. Local water reservoirs are also being adjusted to manage inflows and prevent overflow.

Residents in high-risk areas should prepare for emergency evacuation and avoid travelling through flooded or landslide-prone routes during the warning period.

The ONWR also urged close monitoring of medium and small reservoirs that are currently storing more than 80% of their capacity across several provinces, including Lampang, Nan, Phitsanulok, Saraburi, Sakon Nakhon, Udon Thani, Chaiyaphum, Kalasin, Nakhon Phanom, Khon Kaen, Nakhon Ratchasima, Si Sa Ket, Ubon Ratchathani, Prachin Buri, Sa Kaeo, Chon Buri, Chanthaburi, Trat, Surat Thani, and Krabi.

In addition, the ONWR has instructed relevant agencies to urgently release water from reservoirs that have already exceeded capacity, such as:

• Huai Thong and Huai Suang reservoirs in Sakon Nakhon
• Nong Ya Ma reservoir in Kalasin
• Dan Chumphon reservoir in Trat

As well as major water bodies like Kwan Phayao, Nong Han, and Nong Kut Ting, to prepare for the expected heavy rainfall.

Ing and Sai rivers on flood watch

Areas at risk of sudden water level rises and riverbank overflows, particularly in low-lying regions, include:

• Ing River (Chiang Kham, Thoeng, Phaya Mengrai, Khun Tan, and Chiang Khong in Chiang Rai Province)
• Sai River (Mae Sai District, Chiang Rai Province)

These areas may be affected by accumulated rainfall.

Mekong River levels rising but not yet overflowing

The ONWR also reported that water levels in the Mekong River are continuing to rise due to accumulated rainfall in the Lao People's Democratic Republic (Laos). However, current levels have not yet reached flood stage in Thai provinces along the Mekong, such as Chiang Rai, Loei, Nong Khai, Bueng Kan, Nakhon Phanom, Mukdahan, Amnat Charoen, and Ubon Ratchathani.

To prepare for potential emergencies, the ONWR has ordered the following actions:

1. Closely monitor rainfall and water levels, especially in areas receiving more than 90 mm of rain within 24 hours, or areas historically prone to flooding or waterlogging.

2. Inspect and repair river embankments, remove obstructions in waterways, and coordinate water management plans across reservoirs and catchment areas, from upstream to downstream, while considering tidal influences.

3. Activate flood response plans, ensuring that personnel, machinery, equipment, and communication systems are ready for immediate deployment to assist affected residents.

4. Inform and warn the public in advance, so that those in at-risk areas can relocate belongings to higher ground or evacuate promptly in the event of an emergency.