Rescue workers also directed traffic after slides blocked the Lampang-Phrae road at Ban Pha Lad, eight kilometers from the Lampang provincial seat, leaving only one lane passable for inbound and outbound traffic.
The Lampang-Phayao road at Ban Dong subdistrict office in Mae Mo was hit by landslide while the municipality was flooded with forest runoff.
Many routes including the Chiang Mai-Hot, Chiang Mai-Mae Sariang (Mae Hong Son) were flooded as the water level on the roads continued to rise, with the strong currents making the roads inaccessible to all kinds of vehicles.
Tourists and residents alike were stranded at Hot in Chiang Mai, with hundreds of vehicles unable to move along roads that were underwater.
In the central province of Pathum Thani, flooding remains critical, with the Mon community at Chiang Rak Noi subdistict under two metres of floodwater. The authorities cautioned residents that the floods could continue for at least three months.
The Pathum Thani Provincial Adminstration Organisation strengthened its temporary dyke with 80 cm to 140 cm of added earth as the water level in the Chao Phraya River is still high and shows no sign of receding.
Lampang Airport has been flooded, with 100 metres of runway under one metre of water.
The Lampang aeronautical communications center Monday morning instructed pilots of a 70-seat Bangkok-Lampang flight to divert to Chiang Mai for an alternative landing there instead.
Passengers on-board the diverted flight were transported to Lampang by surface.
In addition, a Lampang-Bangkok flight was cancelled Monday, unable to take off due to the flooded runway.