The north, northeast and central plains of Thailand have been worst hit and Bangkok — much of it only two meters (6.5 ft) above sea level — is now in danger as water overflows from reservoirs in the north, swelling the Chao Phraya river.
At least 289 people have been killed around the country by heavy monsoon rain, floods and mudslides since late July.
“Bangkok may face some problems in areas that are on the outer sides of the irrigation dikes but water levels will not be too high. But inner Bangkok has extremely high defenses,” Yingluck told reporters.
“In conclusion, Bangkok should still be considered safe,” she said.
Run-off water from the north will arrive in the Bangkok area at the weekend at the same time as high estuary tides hamper the river’s flow into the sea. This may also coincide with storms and heavy rain.
“During October 15 to 18, it may be a dangerous time because water from the north will be coming in ... But I confirm it has not reached a crisis stage as of this moment,” Bangkok Governor Sukhumbhand Paribatra told reporters.
He said the level of the Chao Phraya river could rise to 2.20 meters from 2.13 meters over the next few days and some riverside communities should think of evacuating.
Embankment walls along the river in much of inner Bangkok are 2.50 meters or higher.
Despite the reassurances, residents have stocked up on bottled water and foodstuffs such as instant noodles.
The central bank has advised the finance sector to take precautions and told commercial banks to make sure they have enough cash. It said 104 bank branches had closed because of flooding, mainly in the central region.
Bangkok accounts for 41 percent of the economy and contains some heavy industry, as well as extensive service, banking and tourist facilities.
In comparison, the central region, which has been badly flooded, causing several huge industrial estates to close, accounts for 8 percent of GDP. The eastern region, with its international car plants and refineries, accounts for 16 percent but has barely been affected by the flooding.
Late on Thursday, residents in an area covering a northern Bangkok suburb received a warning to evacuate from the government’s crisis control center after a sluice gate had supposedly burst, but it turned out to be a false alarm.
Kittirat Na Ranong, deputy prime minister in charge of the economy, told reporters on Thursday that the flood damage was estimated at more than 100 billion baht ($3.2 billion), over 1 percent of GDP, and could get worse.
He broke into tears as he spoke with workers at the flooded Hi-Tech Industrial Estate in Ayutthaya province.
At least three big industrial estates in the province have shut temporarily. A Nikon Corp. digital SLR factory and a Honda Motor Co. Ltd. assembly plant have closed.
Consumer confidence fell in September because of the floods and could plunge in October, according to economists at the University of the Thai Chamber of Commerce.
Last week, the university cut its forecast for GDP growth this year to 3.6 percent from 4.4 percent but it cut it again on Thursday to 3.0-3.5 percent.
The Finance Ministry has cut its growth forecast to 3.7 percent from 4.0 percent.