Bangkok's Centennial Park fights flooding in a sinking city
When Thai architect Kotchakorn Voraakhom was a little girl she used to play in the flood waters of Bangkok. Now, she's helping to reduce flooding in the city with her innovative urban design.
Bangkok, a city of more than 8 million people, sits in the low-lying Chao Phraya River Delta and is on average just 1.5 meters above sea level. Heavy rainfall in the wet season makes it vulnerable to flooding.
To make matters worse, sea levels are rising, and the city is sinking -- under the weight of its buildings and because too much water has been pumped from the aquifers beneath it.
But help is coming from an unlikely source -- a park in the heart of the city.
Centennial Park, built on the campus of Chulalongkorn University, is a beautiful green space complete with fountains, exercise bikes and a children's playground.
Designed by Voraakhom and her landscape architecture firm Landprocess, there's more to this 11-acre (45,000 square meter) park than meets the eye.
"This park isn't just (about) beautification or recreation," Voraakhom told CNN. "It's helping the city deal with water."
How it works
Numerous design features combine to help the park store rainwater and save the surrounding streets from flooding during heavy rains.
The park is built on an incline, and its slanted main lawn and the angled roof of the park's museum combine to funnel rain water into its sloped gardens.
As it runs through the gardens, the water collects in artificial wetlands. From there, the water flows into a retention pond, which can hold nearly 480,000 gallons (1,800 cubic meters).
Beneath the porous ground is a water tank with a capacity of nearly 160,000 gallons (600 cubic meters). In all, the park can hold up to one million gallons (4,546 cubic meters) of water.
"We need to rethink our city," said Voraakhom. "It's not about getting rid of floods or engineering solutions of building a big dam, but it's about how (we) can live with water."
Herbert Dreiseitl is a landscape and waterscape architect, and a visiting professor at the National University of Singapore. He told CNN the project is a good example of how to creatively use the landscape for a multifunctional purpose.
"This kind of project ... starts where the rain is landing on the surface -- on open spaces, on green parks, on rooftops -- and it's delaying and handling the water the right way," he said.
Greening the city
The park also provides green space in a heavily developed city, says Dreiseitl, making Bangkok more attractive and people friendly.
According to the Asian City Green Index, which compares 22 major Asian cities, Bangkok has just 3 square meters of green space per person, which is far below the index average of 39 square meters per person.
The park, which was completed in March 2017, is too small to have an impact beyond the immediate neighborhood, but Voraakhom wants it to act as a case study for other places, showing that cities can be re-engineered to combine landscape architecture with green solutions.
"This is a kind of soft revolution in city planning," said Dreiseitl. "It will take some time, but these good solutions are convincing for other private investors and government structures or municipalities to follow this model."
He added that this kind of park could work in other cities, but a lack of space and resources might be an issue.
Landprocess is now working on a similar park at Thammasat University, in Pathum Thani province, a flood-prone area just north of Bangkok.
According to the company, the park will be three times larger than Centennial Park and have triple the water-storage capacity. It is set to open next year.