Officials are taking advantage of low tide to divert massive runoff in the Phetchaburi River back into the Gulf of Thailand over the next five days after it overflowed and swamped parts of Kaeng Krachan, Tha Yang and Muang districts.
The river became swollen after officials rushed to discharge water from the Kaeng Krachan and Phetch dams when sections of the Kaeo Noi River in the neighbouring province of Kanchanaburi and the Mekong River and its branches in Nakhon Phanom in the Northeast burst their banks.
The Royal Irrigation Department is coping with inundations in Phetchaburi by pumping water from flooded areas back into the Phetchaburi River and, at the same time, building walls of sandbags in six areas to protect from a new round of overflows.
Water-propelling boats have been stationed at the end of the river near Wat Khung Tamnak in Ban Laem district to speed up water flow into the Gulf of Thailand during low tide, department chief Thongplew Kongjun said yesterday.
The river runs downstream from the Kaeng Krachan Dam in Kaeng Krachan district in the west of Phetchaburi, flows into the Phetch Dam in Tha Yang district, and passes Muang district before pouring into the Gulf in Ban Laem.
"In five days, floods along Phetchaburi River should ease off," Mr Thongplew predicted.
The latest inspection of the Phetch dam found its level was still dangerously high, Interior Minister Anupong Paojinda said.
Speaking during a visit to flood victims in two villages in Tha Yang yesterday, Gen Anupong said he had been informed that farmland in the province had suffered "great damage", but officials would have to wait to provide assistance.
Riverside communities in Kanchanaburi's Sai Yok district are bracing for overflow from the Kaeo Noi River after officials increased the rate of daily discharge of water from the Vajiralongkorn dam.
The dam was yesterday said to be at 91% of its capacity.
"The discharge will increase the water level in the Kaeo Noi River by about one metre," dam director Waiwit Saengphanit said.
The discharge from the dam will take about 12 hours to reach Sai Yok and three days to reach Muang district, located 250 kilometres from the reservoir in the remote Thong Pha Phum district.
Muang, the province's city centre, is where the Kaeo Noi River merges with the Kaeo Yai River.
Water levels in the Kaeo Noi should only increase by between 20cm and 30cm on average because the river gets wider in Muang, Mr Waiwit said.
"All in all, people living downstream [of the Kaeo Noi] should not be much affected," he said.
Srinagarind dam, which sits on the Kaeo Yai in Kanchanaburi's Si Sawat district, is among five dams currently at more than 80% capacity, according to the Royal Irrigation Department.
The others are Vajiralongkorn dam, Khun Dan Prakarn Chon dam in Nakhon Nayok, Pran Buri dam in Prachuap Khiri Khan and Rajjaprabha dam in Surat Thani.
Water levels in the Kaeng Krachan and Nam Un dams in Sakon Nakhon are already 7% above their capacities.
