Super 'floodway' mooted for Thai floods

A new floodway would help prevent flooding in Bangkok

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[BANGKOK] Researchers from a Thai university have come up with a proposal for a 'super express' floodway to help reduce the impact of future flooding on Thailand's capital, Bangkok.

The idea came from Chulalongkorn University's Unit for Disaster and Land Information Studies and would make use of existing irrigation canals that run in parallel to the Chao Phraya River.

Thanawat Jarupongsakul, the leader of the study, said the team proposed to widen the canals and leave a kilometre-wide stretch of empty land alongside them. Motorways running to and from Bangkok would be raised six metres from the ground on both sides of the expanded floodway to act as its dykes.

He said the project would cost about 30 billion Thai baht (around US $1 billion) but, by utilising existing canals, would be much cheaper than digging a new waterway. It would also need less energy as it would mainly rely on gravity, rather than pumps, to drain the water, he added.

The expanded floodway could hold 1.6 billion cubic metres of water and it could drain about 500 million cubic metres of water a day — equivalent of 2.5 Olympic-sized swimming pools a second.

This year's flooding in Thailand has been described as the worst ever, affecting over 2.3 million people.  

Thanawat said that this is only one of the 11 non-structural measures that they are proposing to help Bangkok remain safe from severe flooding.

Other measures include: an overhaul of the disaster warning system; urban development control for Bangkok and new satellite towns; flood taxes and insurances and flood risk maps for urban development and city planning.

The researchers have also proposed: water management plans and ground water use control; climate risk and farming plans; water retention area conservation plans; disaster management plans; and a new disaster management agency.

"The floodway is good, but it alone can only partly help the city to deal with severe flooding," admitted Thanawat. "It needs to be implemented with the other measures."

A source in the government's flood command centre said that senior officials were interested he team's super floodway idea but said that long-term maintenance could be a problem given that even maintaining the capacity of existing floodways is problematic.

Sutat Weesakul, director of research projects at the Asian Institute of Technology's School of Engineering and Technology, said the idea is good in principle as the city desperately needs a channel through which the floodwaters can flow through.

But there is need for more discussion on details to ensure its effectiveness and concerns about its maintenance, said Sutat.