Flash floods hit Thai province as heavy rain inundates homes and roads

Heavy rainfall has triggered flash floods across parts of Nan province in northern Thailand, flooding homes and roads, damaging infrastructure and forcing authorities to assist residents in affected areas.

The Nan Provincial Disaster Prevention and Mitigation Office reported on Wednesday morning that heavy rain began falling at about 8am, generating runoff from forested areas and causing rivers and waterways to overflow.

Several districts have been affected, with flooding reported in residential communities, farmland and roads. Authorities have urged people in low-lying and foothill areas to monitor water levels and prepare for possible evacuation.

Homes and roads inundated in Pua

Pua district was among the worst-affected areas after heavy rainfall caused runoff and waterways to overflow.

Flooding was reported in several villages, including Moo 2, 8 and 10 in tambon Ouan; Moo 3, 6 and 7 in tambon Woranakhon; Moo 1 and 5 in tambon Sila Laeng; Moo 2 in tambon Chai Wattana; and Moo 1, 4, 7 and 8 in tambon Pua.

Floodwaters entered homes and several roads became impassable because of flooding and landslides, according to the Nan Provincial Disaster Prevention and Mitigation Office.

Flooding was also reported in other parts of the province, including Moo 11 in tambon Fai Kaeo, Phu Phiang district; Moo 4 in tambon Muang Chang; and Moo 1 in tambon Phong, Santisuk district.

Authorities have been helping residents evacuate from flooded areas while conducting preliminary assessments of damage.

More than 200mm of rain recorded

Nan municipality said more than 200 millimetres of rain had fallen in some areas, particularly Pua, Santisuk and Mae Charim districts, since midnight.

The rainfall caused flash floods in northern parts of Nan province, while water levels in the Yao and Wa rivers were continuing to rise.

Khaosod English reported that heavy to very heavy rain was continuing as of 6am on Wednesday, with flooding affecting homes, farmland and roads in several areas.

The municipality urged residents in communities at risk of flooding in Nan city to move belongings and vehicles to higher ground and prepare to evacuate vulnerable people.

Particular attention was given to areas that experienced flooding in 2006 and 2024.

Residents who choose to remain at home were advised to prepare at least three days of food, drinking water and medicines, as well as lighting, cooking and communication equipment.

Authorities warned that electricity supplies could be suspended in some areas.

Bridge collapses on Highway 1256

Flooding and strong currents have damaged infrastructure in several locations.

A bridge on Highway 1256, along the Pua–Bo Kluea route, collapsed, making the road impassable to all vehicles.

Authorities advised travellers heading towards Bo Kluea to use Highway 1081 through Santisuk as an alternative route.

The Nan Highway Office 2 also reported flooding on several other roads.

Traffic was halted on Highway 101 between the Chang Phueak and Pua intersections, while Highway 1371 between Teentok and the Ban Mon area near Ban Fai Bridge was also affected.

Highway 1256 was flooded at locations between Pua and Doi Phu Kha National Park, where the collapsed bridge further disrupted access.

Officials installed warning signs and safety equipment and advised motorists to avoid affected routes.

Irrigation weir damaged by strong currents

In Santisuk district, strong currents washed away one side of the Na Lao irrigation weir, damaging the road beside the structure, according to the Nan provincial public relations office.

Persistent heavy to very heavy rain caused waterways in the district to overflow, flooding homes, agricultural land and roads.

Ban Pang Chang in Pong subdistrict was among the affected communities.

The Phayaeng–Kiew Muang road, which provides access towards Nan's provincial capital, was rendered impassable by flooding.

Rescue teams assist stranded residents

Authorities have also carried out rescue and evacuation operations as floodwaters rose.

A motorboat from the Pa Laeo Luang Subdistrict Administrative Organisation was used to assist residents stranded near floodwaters in Ban Sri Bun Rueang, Pong subdistrict.

Strong currents made the operation difficult.

Residents were also stranded on a bridge over the Muap stream at Ban Nam Song in Du Phong subdistrict. Santisuk district authorities later reported that everyone on the bridge had been brought to safety.

The Department of Disaster Prevention and Mitigation urged local authorities to move vulnerable residents, including elderly people and bedridden patients, to safer locations where necessary.

Cell Broadcast warning issued

The Department of Disaster Prevention and Mitigation issued a Cell Broadcast warning for flooding in Pua district earlier on Wednesday.

Residents were instructed to move their belongings to higher ground immediately.

The warning followed reports of flooding across Pua, Chiang Klang and Tha Wang Pha districts, particularly around the Nam Pua and Nam Khuang waterways.

Authorities have continued to monitor rainfall and water levels while assisting residents in affected communities.

More rain forecast across northern Thailand

The Northern Meteorological Centre issued a weather advisory at 7am on Wednesday, reporting light to moderate rain across all districts of Nan and neighbouring provinces including Phrae, Phayao, Lampang, Lamphun and Chiang Rai.

The rain was moving towards the south-west.

Residents were advised to exercise caution when driving because of slippery roads and reduced visibility.

People living in low-lying areas and communities near foothills were also advised to monitor rainfall closely, as continued precipitation could result in further flooding and flash floods.

The authorities have urged residents to follow official warnings and prepare to move to safer areas if conditions deteriorate.