Residents of the Thai capital waded through waist-deep waters in some areas on Monday, while thousands sheltered in evacuation centres following flooding brought by weekend rains, as swelling reservoirs in an eastern province prompted evacuations.

Entire neighbourhoods in Bangkok were inundated, and the drainage network swamped after 320 millimetres (12.6 inches) of rain fell during two or three days last week, or nearly as much as the sprawling low-lying city usually gets in all of September.

“We have no more food to eat, because we didn’t prepare in time,” said Bangorn Dednuam, 60, as she braved intermittent showers in a hunt for food, after supplies ran out at home.

“We didn’t manage to pack our things in time, so there’s nothing stocked in the fridge.”

Bangkok is among 41 provinces across Thailand hit by floods since September 16 that killed at least eight people and disrupted more than 580,000 homes, the interior ministry said.

“Over 80,000 residents living in flooded areas are unable to leave their homes,” Unsit Sampuntharat, the ministry’s permanent secretary, said in a statement, adding that mobile kitchens and boats were being pressed into the relief effort.

“The goal is to provide three meals a day to all residents throughout the … flooding period and for at least another seven after waters recede,” he added.

Damage estimated at $320m

The floods could cause economic damage of at least 11 billion baht ($327 million) nationwide, with losses likely to rise unless the situation improves, said Aat Pisanwanich of Rangsit University’s economics department.

“The flooding is expected to shave 0.3 percentage points off this year’s GDP growth, reducing growth to 2.1pc, and cut third-quarter growth by about 0.5 percentage points to 1.7pc,” he told Reuters.

Southeast Asia’s second-largest economy, which has lagged regional peers since the Covid-19 pandemic, expanded 1.9pc year-on-year in the year’s second quarter, but that was still down sharply from the previous quarter’s growth of 2.8pc.

Bangkok and the eastern region are likely to take the brunt of the impact, particularly wholesale and retail businesses, while industry and agriculture will suffer elsewhere, Aat added.

Economic damage to the capital itself could reach about 7 billion baht, the University of the Thai Chamber of Commerce said in a statement that put the nationwide impact at about 12.3bn baht.

Floating flood market

In Bangkok’s hard-hit neighbourhood of Bang Kapi, people trudged through floodwaters to buy essentials from vendors, some of whom set up stalls with floating plastic boxes and drums, three days after the incessant rains.

Marisa Singprakhon brought her wares out of a shop and moved to the market’s edge to make it easier for customers to buy, but she herself had to stand in waters knee-deep.

“Customers don’t want to go in; they don’t want to stand in the water for a long time,” she said. “So we have to stand in the water outside to sell.”

At least 5,901 people in Bangkok have moved to 234 evacuation centres, a city administration official said.

Sitting on a river delta of soft clay just 1.5m above sea level, Bangkok is sinking by several millimetres a year, while its population of more than 8.4 million often battles floods in its six-month-long rainy season.

Further east, in the coastal province of Rayong abutting a major industrial belt, authorities ordered evacuations on Monday after floodwaters swelled two reservoirs beyond their capacity.

Last year’s catastrophic southern floods, triggered by 630mm of rain over three days, killed at least 145, inundated more than 33,000 homes and damaged critical facilities such as schools, hospitals and highways.