The Ministry of Water Resources and Meteorology has warned that several provinces in the lowlands along the waterways and rainfall catchment area of the mountains and plateaus may face flash floods this weekend or early next week.

The warning came as a low pressure system over northern Thailand, Laos and Vietnam moved downwards and increased its influence over Cambodia just as the southwest monsoon increased speed from medium to moderate.

Meteorological officials forecast that from September 7-13, the provinces in the mountains and plateaus and lowlands and near waterways – including Preah Vihear, Ratanakkiri, Kampong Thom, Oddar Meanchey, Banteay Meanchey, Battambang, Siem Reap, Pailin, Pursat and Kampong Speu – will experience medium to moderate rainfall. The coastal provinces of Kep, Kampot, Preah Sihanouk and Koh Kong will experience strong winds and heavy surf.

“From September 6-9, parts of some provinces in the lowlands, waterways, mountains and plateaus may receive heavy rain for several days, which could cause flash floods. The coastal region may see high winds and large waves from September 7-9. We urge the public to exercise caution,” said a press release.

As of September 6, water levels in the Cambodian-Thai border streams in Banteay Meanchey province had not changed, according to Poipet town governor Keat Hul.

“The water levels in the streams are normal and the sky is clear. However, we are prepared to deploy all available means in the event of flooding,” he said.

In neighbouring Oddar Meanchey province, water resources department director Nen Kuon told The Post that the areas most vulnerable to flash floods include Samrong town’s O’Smach and Konkriel communes.

He likened the geography of these two communes to the bottom of a pot or rainfall catchment area because they are surrounded by hills and plateaus.

“Generally, flooding caused by heavy rain does not last too long. That being said, it could happen very quickly, which causes problems,” he said.

In Preah Vihear province, water resources department director Chap Koy told The Post that the Stung Sen River in the provincial town had swollen slightly due to heavy rains in the upper part of the catchment area of the Mekong Basin, in Laos and Thailand.

It had not yet caused floods, or inundating the homes of any families as of press time.

He said authorities had informed residents living along the rivers and waterways throughout the province to be extra vigilant and had prepared resources that could be deployed should disaster strike.

The rise of the Stung Sen River in Preah Vihear province has caused it to rise above its alert level downstream in Kampong Thom province, according to He Koeun, director of the Kampong Thom water resources department.

“As of September 6, the river was 36cm above its alert level. So far, flooding has inundated over 8,000ha of paddy fields,” he said.

In Koh Kong province, authorities said there had been strong winds and large ocean waves, but there had not been any flooding.

Deputy governor spokesman Sok Sothy told The Post that it had rained for two days in a row, but there had been no flooding in any part of the province.

“Thanks to the ministry’s notification, we warned our people to be careful and temporarily suspend fishing activities to avoid the risks posed by strong winds and large waves at sea,” he said.