Keeping Bangkok dry in future

Options are to build tunnel or dyke; or move the capital
Nirmal Ghosh Straits Times 18 Nov 11;

BANGKOK: Even before the swirling waters have receded from the streets of Bangkok, experts are working out how to prevent a repeat of Thailand's worst floods in 50 years.

Construct a huge tunnel under Bangkok from north to south. Erect a giant dyke out at sea. Move the capital city.

If there is one bright side to the massive floods that have killed more than 550 people and cost over US$5 billion (S$6.5 billion) in estimated damages, it is the huge wake-up call to finally make long-overdue investments in the city's drainage system.

'If we have to do something, we have to do it now,' said Dr Smith Dharmasaroja, a meteorologist who sits on a committee tasked with overhauling Thailand's water management system. 'Five years later, it will be too late.'

The city is also sinking, thanks to natural subsidence and the draining of underground aquifers to provide water to its population of around 10 million.

Much of Bangkok is already below sea level, and depends on its system of dykes, canals and pumps to keep dry. The city is also at risk from the south, as rising sea levels in the Gulf of Thailand steadily erodes the coast.

Experts like Dr Anond Snidvongs, a climate change scientist at Chulalongkorn University, have long warned that if nothing changes, large parts of the capital could be under water in 50 years.

Dr Smith, the meteorologist who famously predicted the Indian Ocean tsunami of 2004 - 17 years before it happened - has an even starker prognosis.

'I think it will take less than 50 years to lose Bangkok, maybe 15 years at the most,' he said in an interview with The Straits Times.

He blamed the floods on mismanagement, adding: 'We know exactly what is going on; we have a 50-year record of storms coming into Thailand. We have the data, but nobody takes it seriously.'

One problem is that many government departments are involved in water management, but 'they don't talk to each other', he said.

The options before the committee are far from easy.

One is to build a huge tunnel to channel flood waters from north to south under Bangkok, pushing the deluge out to sea.

Another is a 'floodway' - a sort of super canal, possibly with an expressway running above it. But land would have to be acquired for that, and because Bangkok is flat, with no slope towards the sea, the water would still have to be driven out to the Gulf.

Another option is to dredge low-lying wetlands north of the city, converting them into huge lakes that can hold large volumes of water. But Suvarnabhumi International Airport is located there.

To address the threat from the south, experts are considering a dyke out at sea that will hold back the erosion of the coastline.

Yet another option is to move the capital. But that is probably no longer possible, because Bangkok's urban infrastructure - especially in terms of transport - has improved in recent years and attracted even more people.

The most that could be done to relieve the density of the city is to move government offices to the nearby province of Nakhon Nayok - a plan that has been mooted before but, like many others, has been left sitting on the shelf.

But now, the devastating flood is pushing the government to finally find a solution - and soon.

King's advice on water management largely unheeded
Straits Times 18 Nov 11;

FEW people have thought as much about water management in Thailand as King Bhumibol Adulyadej, who in his youth trained as an engineer.

But few have heeded his constant warnings.

As far back as 1971 the King flagged widespread logging in the north as a trigger for future floods.

Forty years later, as Thailand battles epic floods, deforestation is being blamed for the rushing flow of rain water that filled northern dams to capacity a few months ago. That, combined with a decision to hold water in the dams in anticipation of a dry season drought, led to the reservoirs swelling to capacity - forcing the release of huge volumes of water from several dams all at once.

In a 1990 speech, the King, commenting on the kingdom's frequent floods, said: 'The major cause... is the fact that we built our houses on wetlands. My point is that humans have changed nature so much from what it used to be.'

The wetland is a key absorber of water. Conversion of wetlands to other uses - especially to large urban infrastructure - reduces that capacity.

Five years later, speaking to a roomful of officials discussing drainage plans for Bangkok, he said: 'In the future, we will face more problems from sea water rising up.'

He emphasised the importance of wider canals, and pumps to propel the water out to sea.

Some of his advice was heeded; Bangkok depends on a battery of close to 200 pumping stations. But in the current crisis, all the pumps have been working 24 hours a day, seven days a week. They are not designed for such prolonged use, and many have burned out.

Thankfully, there were no heavy storms and sudden electricity failures, Bangkok Metropolitan Administration (BMA) engineer Supachai Tantikom said. Otherwise, the city would have been submerged.

But some of the King's advice was also ignored - an odd phenomenon in a country where the King is the ultimate moral authority and Thais from all walks of life hang on to his every word.

'People didn't think it was such a serious threat, I suppose,' said Dr Supachai.

Veteran meteorologist Dr Smith Dharmasaroja also said: 'People didn't believe this could happen.'

King Bhumibol is known to have been unhappy with the choice of location of the city's international airport, which took years to build and was finally commissioned in late 2008. But successive governments went ahead anyway.

In an interview in an office at the BMA, Dr Supachai pored over a map of Bangkok's drainage system and brought his palm down on an area east of the city which once was a vast wetland called Cobra Swamp and now features the sprawling Suvarnabhumi International Airport.

'It shouldn't be there,' he said.

NIRMAL GHOSH