THE ROYAL Irrigation Department (RID) started to release water through Chai Nat’s Chao Phraya Dam beyond the rate of 2,000 cubic metres per second yesterday.
RID deputy chief Thongplew Kongchan said the department aimed to handle runoff from the north and heavy rainfall by gradually increasing the dam’s water release rate to 2,600 cubic metres per second and keeping it there for a week.
This would lead to the river level from Chai Nat to Ayutthaya rising by 0.80-1.20 metres over this period, he said.
Officials have been told to prepare flood-fighting tools and closely follow the situation in downstream areas so they can provide timely aid to residents.
Yesterday, water running through Nakhon Sawan – which is upstream of the Chao Phraya Dam – was flowing at 2,528 cubic metres per second and was 1.97 metres away from overflowing the river banks, while the dam was releasing water at a rate of 2,188 cubic metres per second.
To lessen the impact on riverside residents, the RID is also diverting water in Nakhon Sawan at a rate of 474 cubic metres per second via irrigation canals into water-retention fields on both sides of the Chao Phraya River, he said.
Yesterday, the eastern water-retention fields contained 387.40 million cubic metres of their combined capacity of 437 million cubic metres; and the western side’s fields contained 500.27 million cubic metres out of their combined capacity of 1,077 million cubic metres.
In the Pasak River basin area, heavy downpours caused a large deluge of about 42 million cubic metres per day pouring into Lop Buri’s Pasak Jolasid Dam, which yesterday reached 91 per cent of its capacity, or 878 million cubic metres.
This prompted the RID to release water at 30 million cubic metres a day, compared to the normal rate of 25 million cubic metres, to boost the balance between the incoming and outgoing water, he said. As a result, the Pasak River rose by 0.30 metres yesterday.
Meanwhile, officials raced against time to reinforce two-metre-high flood levees along the Chao Phraya River that run through the heart of Angthong’s Muang district after the water level reached a crisis level yesterday morning.
According to the deputy mayor of Muang Angthong Municipality, Thanongsak Sriwichian, the water level in front of the provincial hall was 8.33 metres, approaching the banks’ height of 9.32 metres.
Water had started seeping out of the flood embankments along the river bank, he said, and water was passing through the measuring station in front of the provincial hall at the speed of 2,071 cubic metres per second.
Thanongsak said officials were reinforcing the embankments with sandbags and draining the seeped-in water in an attempt to prevent flooding in the government centre and business area in the heart of the province.
The rising Chao Phraya had flooded 1,297 houses in five Anthong provincial districts outside the flood embankments, officials said.
In Ratchaburi’s Bang Phae district, the 15cm-deep floodwater that affected 100 homes in Tambon Bang Phae for almost a week has now started to become polluted and is sending off a foul smell. Officials yesterday delivered relief bags and inspected the scene to find ways to enable fast drainage.