Sourced from Fast Company
Sitting on former swampland in a low-lying river delta, Bangkok has always flooded. In the 1800s, the majority of the population lived in floating homes and a Venice-like network of canals served as major streets; some of the land was used for farming. But as the area has grown into a sprawling megacity, canals have been filled to make way for development. Rice paddies and fruit plantations have been paved over. As there’s less room for water to go, floods have gotten worse. The problem is compounded by the fact that the city is slowly sinking, while sea levels rise. Climate change also makes heavy storms more common.
At the center of the city, a new park is designed to help with flooding: In a major storm, the 11-acre park can hold nearly 1 million gallons of rainwater. “It floods in the rain garden rather than on the street,” says Kotchakorn Voraakhom, a landscape architect and founder of the urban design firm Landprocess, who designed the park for Chulalongkorn University, the city’s oldest university. Voraakhom is also a TED fellow.
The park, called Chulalongkorn Centennial Park, slopes gently upward, creating a small hill in the otherwise flat city. Built on land owned by the university, the park is part of a plan to revitalize this area of central Bangkok. At the highest end, a museum is topped with a large green roof covered with native plants. When it rains, water filters down into three large storage tanks under the museum; in the dry season, the water can be used to irrigate the park. Rain also flows down through four wetlands in the park, where a series of plant-filled ponds help filter the water. At the lowest point in the park, water ends up in a small retention pond.
When rainfall is light, the retention pond can contain all of the water. But in a heavier storm, the water can expand upward into the main lawn of the park. Next to the museum, the slightly concave lawn can hold more than 100,000 gallons of water. “This infrastructure is not about getting rid of flooding,” says Voraakhom. “It’s about living with flooding.”