Many residents of slums along the Lat Phrao canal and other waterways remain reluctant to relocate, despite offers of affordable new homes, so that flood defences can be improved. (Thiti Wannamontha)

Rung, 63, fought a running battle against the rubbish and raw sewage besieging her old home in a wooden slum perched on stilts on the banks of the Lat Phrao canal in Sai Mai district of Bangkok.

“You could see and smell the daily flow of trash,” recalled the tailor. “It would stop at the back of my house. I wanted a better life for my son and daughter.”

On Christmas Day last year, Ms Rung moved into a brand-new, blue-painted house just a few metres away from her old one in the Chao Phor Somboon community in Sai Mai — part of a campaign to clear waterways of illegal settlements that contributed to catastrophic floods in 2011.

Ms Rung, who now pays just 65 baht per month towards the 200,000-baht construction cost of her new two-room home, is one of the successes of a project along the Lat Phrao canal launched almost two years ago, which is so far only about one-third complete.

The authorities have struggled to persuade most residents to relocate, and are unlikely to meet the project deadline of June 2019, according to a senior official.

Delays to the canal rehabilitation, and the slow progress or abandonment of a flurry of other flood-prevention schemes announced after 2011 could result in a bigger flood disaster in the decades ahead unless urgent action is taken, experts warn.

Besides causing damage worth US$46 billion, the floods six years ago affected more than 3 million of Bangkok’s residents, mostly the poor, across 36 of the 50 districts that make up the capital.

Key causes of the flooding included subsidence, poor infrastructure, weak government coordination, and the blockage of vital waterways by littering and unregulated construction.

Most of those who have moved to new homes in the Chao Phor Somboon community along the Lat Phrao canal in Sai Mai district are glad they did. (Patipat Janthong)

The extensive canal and drainage network that once helped manage the flow of water in the Chao Phraya River has been largely filled in to accommodate the traffic that now clogs the capital’s streets.

And while efforts to better equip the city to handle flood waters have struggled to keep pace with a booming population, the threat from climate change has worsened, experts say.

“The wet places will become wetter, and the dry places will become drier,” said Abhas Jha, a manager for urban development and disaster risk at the World Bank. “What we used to call a one-in-a-hundred-year event is happening more frequently.”


Bangkok is a city that is slowly sinking. Built on a swampy plain, the city has a land subsidence problem made worse by over-pumping of groundwater.

Tapping underground wells was traditionally a way for people to access free water, and at one stage the city was sinking at a rate of 10 centimetres per year.

In the late 1970s, the central government introduced and enforced a new law to help ban groundwater extraction.

The city is now sinking at a smaller rate of 2-3 cm per year — a success story that could be replicated in other cities, researchers said. But it still faces the threat of floods.

Today, Bangkok receives just 3 billion to 5 billion baht per year from the central government to invest in new water management projects, officials said.

As the monsoon season has become increasingly unpredictable, the Bangkok Metropolitan Administration Flood Control Centre has set up a flood monitoring system across the city and an alert system that incorporates social media.

But the city needs to expand early warnings to ensure they do not ignore the poor and rural areas, urban experts said.

“The problems are more complicated today,” said Nambi Appadurai, head of strategy for the climate resilience practice at the World Resources Institute, referring to new construction and Bangkok’s population growth.

“I wouldn’t be surprised to see flooding (like in 2011) happening again. Very little has been learned.”


In an effort to avoid a repeat of the 2011 floods and improve residents’ lives, in 2013 Bangkok joined 100 Resilient Cities, a network backed by The Rockefeller Foundation to help cities tackle modern-day shocks and stresses.

Supachai Tantikom, Bangkok’s chief resilience officer, published a strategy for the city earlier this year, with flooding a key focus.

Mr Supachai believes the Thai authorities should create a new 20-year master plan for flood defence in Bangkok’s 50 districts and surrounding provinces, mapping out each area and making use of the latest data.

“We have flooding every year. This year we have had a few floods during the rainy season, lasting three to four hours … it caused a lot inconvenience,” he said. “Our infrastructure is not sufficient to drain the water.”

Mr Supachai, previously an adviser to the governor of Bangkok, said Dutch experts had already started scoping out a plan, which would cost around 2 million euros.

As in other Asian cities, a lack of coordination between local and central government authorities often makes river management difficult, said the World Bank’s Mr Jha.

A focus on hard infrastructure projects means people think cities can build their way to safety, he added.

“Globally, we find that policymakers love concrete,” he said, noting other measures can be simpler and more cost-effective.

Green infrastructure projects that could help Bangkok include the protection of wetlands and the development of green roofing, permeable pavements and rainwater harvesting.

Dual-purpose facilities — such as car parks that double up as storage spaces for floodwater — are also a relatively cheap method of reducing risk.


Bangkok is now home to more than 10 million people. Rapid industrial growth over the past decade has attracted large flows of people from other parts of Thailand. This migration is set to continue, with the population expected to top 15 million by 2020.

Previously, the city’s water defence strategy focused on strengthening the giant flood wall encircling its centre, and pumping out any excess water.

But as the capital keeps on growing, new approaches will be needed to protect all residents, officials said.

Managing the water surrounding the city and longer-term investments are crucial for the city’s future, according to urban experts.

Rajiv Shah, president of The Rockefeller Foundation, a New York-based philanthropic organisation that funds 100 Resilient Cities, said 70% of the network’s projects in Asia relate to water — from providing clean drinking water to managing storm runoff.

“The huge deficit in infrastructure and infrastructure finance is going to hold back growth and well-being,” he told the Thomson Reuters Foundation. “We see a whole new set of technologies and partners that can come together and do things.”

Back at the Lat Phrao canal, work grinds on to build new homes, reinforce the sides, and dredge the channel.

Ms Rung urged those still in slums by the water not to let stubbornness or pride stop them from moving into new homes.

“I have no regrets about leaving. It is better and cleaner here,” she said.

A dredger removes rocks as work progresses on the construction of an embankment along the Lat Phrao canal. (Patipat Janthong)

News Reporter

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