Flooding in the Chao Phya River Basin will continue until late November because the northern floodwaters moving south are still rising, said Royal Irrigation Department (RID) director-general Samart Chokanapitak yesterday.

The Disaster Prevention and Mitigation Department urged Chao Phya River provinces such as Sing Buri, Chai Nat, Uthai Thani, Ayutthaya and Angthong, plus Bangkok suburbs, especially on the eastern side, to be on high alert for floods.

 Following his helicopter trip to inspect conditions in Nonthaburi, Pathum Thani, Ayutthaya, Angthong, Sing Buri, Chai Nat, Uthai Thani, and Nakhon Sawan, Samart said he was concerned that the flooding would remain longer than previously expected.

With such high water volumes in the central plains, floodwaters were now expected to recede in late November, Samart said.

"Now the rising floodwaters in Nakhon Sawan are overflowing into nearby Uthai Thani while all Chao Phya riverside areas from Nakhon Sawan to parts of Bangkok and Samut Prakan are now in worrisome situations. The Noi, Suphan Buri and Lop Buri rivers are also expected to rise," Samart said.

He warned at-risk communities to check the height and strength of their flood-prevention barriers.

Flying over the flooded landscape north of Bangkok, Samart said slightly flooded areas could take more water. He said the RID aimed to divert excess water from the central waterway in amounts that would not damage crops.

Samart said the Bangkok water volume was 4,216 cubic metres per second yesterday morning, although the 2.7-metre flood barriers were holding as this was the low sea tide period.

The RID will also assess the water-retaining capacity of His Majesty the King's personal properties in Ayutthaya's Thung Makham Yong, Pathum Thani's Rama 9 Pond and Saraburi's Ban Mor Lake. His Majesty earlier this week granted permission for the RID to divert water to the areas to save Bangkok from flooding.

Meanwhile, Disaster Prevention and Mitigation Department director-general Anucha Mokawet said the death toll from the floods was 47 with two missing people, while the cost of damage was about Bt305.3 million, with 1,836,418 rai of farmland affected.

With the Chao Phya in Nakhon Sawan reaching 5,520 cubic metres per second - the highest rate for 60 years - due to Phitsanulok's heavy rainfall and northern floodwaters from Sukhothai, he warned Chao Phya provinces and suburbs in Bangkok to be vigilant.

The Nan River in Phitsanulok hit a new record of 10.29 metres at 11am yesterday and was rising, prompting city residents to hang their hopes on water pumps. The river was expected to reach its highest level for 10 years following the 1995 flood's high of 10.53 metres.

The flood's massive pressure sent inflows through the Muang Phitsanulok Municipality's sewage system to flood three communities.

Some 100 homes and 1,000 rai of farmland along Sa Klo and Khok Chang canals have been under 1.5 metres of water since Thursday.

In Nakhon Sawan, local authorities continued to pump water out of the city's commercial area, while heavy rainfall from Thursday night to yesterday morning saw the Ping River rise by five centimetres, the Nan River by three centimetres and the Chao Phya by four centimetres.

Chai Nat's Chao Phya Dam releasing 3,500 cubic metres per second caused the water to drop only 10 centimetres from the top of the Muang Nakhon Sawan Municipality's concrete barriers.

Pak Nam Pho Market residents constructed their own barriers in front of their shops.

Up north, Chiang Mai's Fang district had disaster prevention officials on flood-watch 24 hours a day.

In Chiang Rai, the Khong River inundated 500 riverside homes and 5,000 rai of farmland and now threatens to flood the ancient city in Chiang Saen district.

Meanwhile, US Ambassador Ralph L Boyce yesterday provided US$50,000 (Bt1.8 million) from the US government in disaster assistance to the Thai Red Cross.