Chao Phraya dam increases discharge, floodwaters to rise, inner Bangkok still safe

Residents of Moo 3 village in Sam Khok district of Pathum Thani province carry possessions from their flooded home to safety. Some parts of the province just north of Bangkok have been hit heavily by flooding. (Photo by Pongpat Wongyala)

The Chao Phraya barrage will release even more water as the dam faces heavy pressure from increasing run-off from the north. Floodwater south of Chai Nat, including Bangkok's adjacent Nonthaburi, could rise as much as 30cm.

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Floods tipped to rise as run-off arrives

Post Reporters

Floodwater in some provinces south of Chai Nat, including Bangkok's adjacent Nonthaburi, could rise as much as 30cm as the Chao Phraya barrage faces heavy pressure from increasing run-off from the north.

The barrage will release even more water, despite authorities' promises to keep the discharge in check.

However, authorities insist that Bangkok will still be saved from flooding.

The Chao Phraya barrage dam is increasing water release to 2,700 cubic metres per second to offset massive run-off from the North, which will affect low lying areas downstream as far as Nonthaburi, on the northern edge of Bangkok. (Bangkok Post file photo)

Royal Irrigation Department chief Somkiat Prajamwong held an urgent meeting Monday to assess the water situation as more run-off from the North has reached the barrage.

He said the Chao Phraya River's Ping, Yom and Nan tributaries were swelling due to heavy rainfall, forcing the barrage to release more water.

The RID will increase the water release to reach 2,700 cubic metres per second on Tuesday, from 2,600 cu/m per second Monday. The new level of the water release will be maintained for a week.

The 2,700 cu/m per second is close to the critical level at 2,800 cu/m per second that the barrage can keep the runoff under control.

Still, the amount is far from the level of water release which the barrage made during the massive flooding disaster in 2011 at more than 3,600 cu/m per second.

Mr Somkiat said floodwater in Chai Nat, Sing Buri and Ang Thong could rise by 25cm on average while Nonthaburi could be hit hard due to high tides. In other Central Plains provinces, such as Suphan Buri and Ayutthaya, the floods were exacerbated by downpours of recent days.

A woman holds the hand of a boy as they wade through floodwater at their house alongside the Tha Chin River in Wat Sing district of Chai Nat. Their community was flooded after water behind the Chao Phraya Dam was diverted to alleviate the hardship of flood-hit people living downstream and upstream from the dam. (Photo by Chudate Seehawong)

The RID chief said the priority now was to speed up the release of excess water in the Chao Phraya River into the Gulf of Thailand. If more persistent heavy rain fell in downstream provinces, the Chao Phraya River could be "choking with water" as all the 12 catchment fields in the Central Plains region are full after part of the floodwater had been diverted to them.

The RID, meanwhile, has set the amount of the barrage's discharge deemed critical for downstream provinces at 2,800 cu/m per second.

At that level, the water could threaten to flood areas in Bangkok on the Chao Phraya River banks as well as some interior communities living close to the networks of waterways connected to the river.

Deputy Bangkok governor Chakkraphan Phewngam has allayed concerns of mass flooding in the city, saying the Bangkok Metropolitan Administration (BMA) has anti-flood measures in place for before, during and after the late King's royal funeral ceremonies.

To protect the old city quarters against water, more than 44,000 sand bags will form an embankment along half a kilometre along the waterways in flood-prone areas with 11 major water pump stations in areas around Sanam Luang and the Grand Palace working at maximum capacity.