Bangkok is sinking, so it built a park that holds a million gallons of rainwater to help prevent flooding

An aerial view of CU Park in Bangkok, Thailand.

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An aerial view of CU Park in Bangkok, Thailand.
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Landprocess

Summertime is Thailand’s rainy season, when Bangkok and other cities can experience powerful storms. In past years, downpours have produced enough rainfall to completely flood city streets, overwhelm drainage systems, and inundate homes.

Making matters worse for Bangkok, the city is sinking at a rate of more than one centimeter a year and could be below sea level by 2030.

To help prevent future flooding, the city and local organizations have recently embarked on several projects, including mapping out an extensive water-management plan this past June.

One of the larger anti-flooding projects is Chulalongkorn University Centenary Park, an 11-acre green space that can hold up to a million gallons of rainwater. As TED notes, Bangkok-based landscape architecture firm Landprocess designed the park to address flooding in its surrounding neighborhoods.

Here’s how it works.


Known informally as the CU Park, the project was built on $700 million worth of land near central Bangkok in 2017.

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An aerial view of CU Park in Bangkok, Thailand.
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Landprocess

Landprocess Founder Kotchakorn Voraakhom, who grew up in Bangkok, led the design plans. The park sits on the campus of Chulalongkorn University, which commissioned the project.


The park features several characteristics that help it retain and redirect floodwater that would otherwise flow into city streets.

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CU Park in Bangkok, Thailand.
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Landprocess

One side of the park sits at an incline that helps funnel water into a giant container.

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Landprocess

The raised green roof directs runoff water through sloped rain gardens with native plants.

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Wetlands at CU Park in Bangkok, Thailand.
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Landprocess

The water then travels through an artificial wetland …

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An illustration of CU Park in Bangkok, Thailand.
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Landprocess

… and drains into a large retention pond that soaks it up.

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An illustration of CU Park in Bangkok, Thailand.
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Landprocess

The wetland also acts as a filtration system, where the water can be treated for toxic materials.


In the case of severe flooding, the retention pond can nearly double in size by expanding onto the park’s main lawn. In total, the park can hold up to a million gallons of water.

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Landprocess

Source: TED


Other sections of the park include an herb garden, trails, and a recreation area.

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Landprocess

A linear rain garden — which also absorbs water — lines the park’s perimeter to protect the outlying roads.

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Water retention ponds at CU Park in Bangkok, Thailand.
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Landprocess

These roads include bike lanes and wide walkways, so that the public can easily access the park on foot.

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CU Park in Bangkok, Thailand.
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Landprocess

“Chulalongkorn Centennial Park is designed to face future uncertainties of climate change,” the firm said in a statement.


Bangkok, a mega-city of 20 million people, will continue to face the threat of sea-level rise and flooding.

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Landprocess

While 11 acres only covers a small portion of the city, CU Park is a step toward a more resilient Bangkok.

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An aerial view of CU Park in Bangkok, Thailand.
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Landprocess

Voraakhom is now designing an even larger park that will mitigate flooding like CU park. Located on the campus of Bangkok’s Thammasat University, it’s expected to open in 2019.