A man wades though flood water at the Buddha Image Market in Bangkok yesterday. Health officials have warned people to be wary of waterborne bacteria or parasites if they walk through deep water.

The Royal Irrigation Department (RID) revealed plans yesterday to get the government to set aside one to two million rai of land as "monkey cheek" areas that can let in and absorb water as a long-term solution to flood problems.

The Chao Phya River Basin did not have enough reservoirs and the natural water-absorbing areas, known as "monkey cheek" areas, were fenced to keep water out, RID director-general Samart Chokanapitak said. This led to rising water levels and extensive flood damage.

The RID's targeted areas include Lop Buri's Tha Wung district, Suphan Buri's Thung Song Phi Nong, plus Ayutthaya's Thung Ban Ban, Thung Maharat and Thung Chao Jet, he said.

The department believed a law was needed to state the areas that would be used to contain floodwater during high-water periods, he said. Farmers would be paid compensation for the "service" but would be obliged to grow plants and harvest as suggested by authorities (and the proposed law).

They could erect barriers on their land but only when water gates were in place. The law may also state that homes must be built on elevated land, or not at all in these areas, he said.

Samart said the RID had diverted water overflows into Thung Sena, Thung Makham Yong and Thung Phukhao Thong and that was sufficient to prevent Bangkok from being flooded during this high sea-tide period.

Farmers on 90 per cent of the areas that helped absorb water had done harvests, Samart said. He said officials did not divert water into parts of Thung Bang Ban where crops had not been harvested.

Meanwhile, three more people were reported dead yesterday in Nakhon Ratchasima, bringing the provincial death toll to 15. A young man drowned in a well in front of his father on Tuesday night, while a toddler and her father drowned yesterday. In Sing Buri, provincial officials warned residents in areas at risk to move belongings to higher ground.

This was after Nakhon Sawan saw its highest water volume in 60 years - 5,145 cubic metres per second, which caused Chao Phya Dam to release water at over 3,000 cubic metres per second. Sing Buri officials rushed to pile sandbags to back up barriers in front of the local town hall, which suffered a 10-metre-crack.

In Bang Rachan district's tambon Mae La, said to have never experienced flooding, nearly 1,000 homes and 5,000 rai of farmland were inundated. And another 1,000 homes in Huai Ta Khe in Muang district's tambon Thon Pho were also submerged.

In Ayutthaya, many historic sites on the eastern side of the river were under one-metre-deep floodwater. Wat Chaiwattanaram stood only 30 centimetres above the water but Wat Thammaram's Scripture Library and its ancient wooden wall paintings were about to be ruined by dampness.

In Suphan Buri, a forest flood damaged 20 homes in Dan Chang district, while over 1,000 homes in Muang district were inundated by the Tha Chin River overflowing.

Up in Chiang Mai, 10 villages in Mae Rim district were hit by forest run-off yesterday morning, but all residents were warned and evacuated in time.

District officials in Fang - hit by a flash flood on Sunday night - estimated the damage to agricultural areas at about Bt50 million. In nearby Chiang Rai province, parts of Mae Chan, Mae Sai and Chiang Saen districts were submerged by the Kham River.

In Phitsanulok, residents were warned to brace for flooding as the Nan River is due to reach 10.5 metres today, which is the same level as the huge 1995 flood.

The Disaster Prevention and Mitigation Department said 17 provinces were now combating floods. But the Weather Bureau said rainfall would decrease in the North, Northeast and Central regions. However, heavy rain is expected in the South, particularly in Phetchaburi, Prachuap Khiri Khan and Chumphon, where locals have been warned of possible flash-floods. Heavy downpours are expected in Bangkok and eastern provinces in the late afternoon and night. And the rain would continue till late this month.