Thailand: Bangkok's secret weapon in war against floods

CU Centenary Park's unique role as an additional rainwater drainage basin points towards a greener solution to the capital's frequent deluges
Bangkok Post 21 Oct 17;

When the torrential rains of Oct 13 caused heavy flooding in Bangkok, several parts of the city were swamped, including Chulalongkorn University Centenary Park in Sam Yan. However, as the park slowly filled with water, Kotchakorn Voraakhom, the landscape architect who designed the project, remained unconcerned. She even expressed her satisfaction in a Facebook post that the park had finally delivered on one of its purposes -- the detention of flood water.

"The CU Centenary Park is designed to serve as a (monkey cheeks) water-detention area for the community. We need more of this flood detaining space in the city," said Ms Kotchakorn, a 38-year-old architect who received a bachelor's degree in landscape architecture from Chulalongkorn University, before earning her master's degree in the same discipline from Harvard University.

Located between Chula Soi 9 and Banthat Thong Road, the park occupies 30 rai of land in one of the city's prime business areas. Surrounded by shophouses and the university campus buildings, the park is half a kilometre from Mahboonkrong Shopping Complex (MBK) and Siam Square.

"I thought a lot about the park and what it might mean in relation to Chulalongkorn University in this context. As a designer, I did not just want to create a space that only glorified the university," said Ms Kotchakorn.

"So I thought about what role the park could play within the community. Then, I thought about climate change as well as the flood problems that Bangkok suffers. I came up with an idea to create a park that could serve as both a public space and also a water management asset," said Ms Kotchakorn, who has designed several high-profile projects such as the green roof of the Siam One Shopping Complex and the new landscape project for Thammasat University, and also several smaller yet equally noteworthy projects such as the swimming pool facility at the Foundation for the Blind in Thailand under The Royal Patronage of Her Majesty Queen Sirikit in Bangkok.

Five years ago, she won the design competition for the CU Centenary Park project, which was commissioned to celebrate the 100th anniversary of the university. Instead of creating a typical public park festooned with decorative trees, the architect chose sloping wetlands to allow the naturally porous earth to detain excess rainwater. Vetiver grass and other water plants were planted to help purify the wastewater, and a water tank added to store water for use in the dry season. Porous concrete allows water to drain underground as much as possible and an earth-based gutter system decorated with flowers and small trees was selected as an alternative to a hard concrete gutter.

Despite its utility, the park was primarily created with the public in mind. It has a walkway for people to stroll along, benches for them to sit and relax on and an underground function room built beneath an ornate garden. The park also provides fixed exercise bicycles for health and fitness. These bicycles, however, serve a dual purpose as the energy generated from people pedalling contributes to the power needed to help oxygenate the wetlands.

"The idea was to make use of natural ecology to manage water. Personally, I think our city has been placing too much hope on engineering solutions, such as flood drainage pipes, which will never be sufficient. Thus, we need to create more green space like this park to help absorb floodwater."

Ms Kotchakorn admitted the park might not be a solution in itself to the problems caused by the area's mass deluges, "But the park can help lessen the severity of floods and afford more time to city drainage officials, while the wetlands can help to treat the dirty water so that it can be stored and used later in the year. Hopefully the park is serving as a pilot scheme to show how green spaces can be adapted to provide ecological solutions to the flooding. Just imagine if we had many more public spaces like this, contributing to effective water drainage, in every nook and cranny of the city."

Opened in March this year, the Chulalongkorn University Centenary Park is the first park in the city designed to show that public parks can help authorities with flood management.

Currently, CU Centenary Park is the only public park in Bangkok designed with water management in mind. Most of the other parks in Bangkok are on flat land and designed to grow trees and decorative plants, according to Danai Thaitakoo, a lecturer in landscape architecture at Chulalongkorn University.

"Bangkok Metropolitan Administration (BMA) does not consider public parks or green areas as natural infrastructure that can help the city manage water," said Mr Danai, who has created flood-detention areas at Chulalongkorn University by altering the surface used and landscape of parking space in pilot projects near the Faculty of Arts and Faculty of Engineers.

Mr Danai said few people understand what flood detention is. "Sometimes, university personnel call me worried that my projects may end up submerging their parking lots! People are afraid to see flood water, they don't want to get their feet wet," he said.

In the old days, Bangkok residents were more at ease with flooding and were happy to wade through it to go about their daily business. The original ecosystem of the city, which is part of a low-lying alluvial plain, was able to cope as excessive water drained naturally. Known as the "Venice of the East", Bangkok had many canals, orchards, trees and green areas which helped to effectively detain floodwater. Now many of those areas have been replaced with concrete surfaces. Fruit and vegetable plantations that would happily soak up the water are gone while housing estates, condominiums and networks of roads keep continue to proliferate.

Mr Danai said many cities around the world, such as in the Netherlands or Singapore, that face the threat of flooding have already enlisted the aid of the natural ecosystem to help them with water management. For example, a project called "Room for the River" in the Netherlands has relocated concrete dykes inland and reduced the scale of concrete infrastructure to give more room to natural flood plains around the country's rivers. In Singapore, authorities redesigned the area around the Kallang River to introduce natural elements such as green areas and flood plains to help in times of heavy rainfall.

Mr Danai said Bangkok could use such examples as models upon which to base the development of its own strategy to combine nature with nous in the pursuit of effective solutions to its own frequent deluges.