More floods are expected in beleaguered Chiang Mai later on Friday, with water levels along the Ping River expected to reach 4.95 metres starting in the morning.
Recent heavy downpours in upstream areas have caused the Ping River to rise rapidly, governor Nirat Pongsitthithaworn said on Thursday.
He advised residents living along the river to move their vehicles and other valuables to higher ground. Hospitals and local clinics in low-lying areas have also been told to move bedridden patients to safer areas in case an evacuation is necessary.
All agencies have been told to provide assistance to people who need it and to reinforce flood-prone areas with barriers and sandbags.
Engineers with Chiang Mai municipality are monitoring conditions along the riverbank and are ready to reinforce any gaps in flood walls, Mr Nirat said.
A flash flood was reported in Mae Rim district of the northern province at 3am on Thursday following heavy rain. The flood damaged several houses and resorts in Rim Nua sub-district.
The depth of the Ping River at the Nawarat Bridge in Muang district reached the critical level of 4.20 metres at 4pm on Thursday, according to the local Royal Irrigation Department office. That was a marked increase from 3.45 metres on Monday.
The river was expected to peak at 4.95 metres at 2am Friday morning.
In Chiang Rai, the Mae Sai River overflowed near the first Thai-Myanmar Friendship Bridge in Mae Sai district at 9am on Thursday following a downpour that began on Wednesday.
Local authorities said that National Highway 118 and some areas in Wieang Pa Pao district of Chiang Rai were also flooded.
In Mae Hong Son, governor Chucheep Pongchai ordered officials to inspect conditions in flooded areas, including the Long-Necked Karen community in tambon Pha Bong in Muang district.
Inundation was also reported in Loei, where heavy downpours caused flash flooding in several residential and farming areas in Ban Nam Chan and Ban Kaeng Hin communities in Wang Saphung district.
The Meteorological Department said downpours in the northern, northeastern, central and eastern regions were expected to start easing on Friday, as a cold front from China moves over the upper parts of Thailand.
However, the western part of the North should expect more heavy downpours until Oct 12, due to the weakening effect of the cold front over the area.