Should L.A. look to ‘sponge cities’ to solve its flooding problem?

In 2019, when the Thai government planned to make a abandoned tobacco factory into a public park in the country’s Smoggy capital, Bangkok -based landscape architect Chatchahanin Sung had the opportunity to appeal to another of the city’s chronic problems.

For Bangkok, a city of 11 million sitting in the low swamp, the administration of the water has become a matter of survival. When the capital opposes the rising sea levels due to climate change, as well as more frequent and excessive rainfall, experts warned that all areas of the city may be under water in the next few decades.

Los Angeles knows how to ventilate one or two or three crises. Angelenos touches this flexibility, trying to build a city for everyone.

Like Los Angeles, where intense droughts and floods reveal the limitations of traditional floods such as La River, Chatchanin felt that Bangkok has reached the overturning point of his own rainwater infrastructure.

The air view shows roads from Benjakitti Park in Bangkok.

(Critical Phromsakla Na Sakolnakorn / Associated Press)

Ten years of rapid urban development has covered the city with non -impermeable concrete surfaces that prevent the natural drainage of water. As a result, more than 1,600 urban channel networks, which were once used to carry goods and people but now act as rain water channels, have regularly overwhelmed.

“The water quality is really bad because the channel water is mixed with sewage -made sewers, C Chatchanin said. “The park project was an opportunity to absorb and clean this water.”

In order to design the new area, Chatchanin, a 102 -acre expansion of the pre -existing Benjakitti Park, has established a partnership with Beijing -based landscape architect who has long been known as the “Sponge City” model of urban water management.

Contrary to the “gray” infrastructure designed to clean the water as quickly as possible, cities like Bangkok can reduce the risk of floods by capturing rainwater before it becomes more absorbent by making its surfaces more absorbent like a sponge, polluting the streets and turning into a flow that pushes drainage systems.

The winning designs that opened to the public three years ago took place in only 18 months and reflects the idea that such urban water management systems can provide valuable aesthetics and entertainment benefits to communities.

Today, the old Brownfield is a popular bird monitoring point. Badminton and Pickleball courts built in reorganized cigarette warehouses have forested walking paths.

People are resting at Benjakitti Park in Bangkok.

(Sakchai Lalit / Associated Press)

A long wetland system, which is fed by a nearby channel, contains the bushes of water plants, wrapped around the surrounding area of the park and removes pollutants from the water and divides the rest to a large pond with small islets.

This allows Bangkok to capture 23 million gallon rainwater in the rain in the rain, as well as the porous landscape and additional holding pools of the park. Instead of being prevented by concrete, water entering the permeable world helps to renew natural underground reservoirs that benefit people and the environment.

“We really had heavy rainfall last year, C Chatchanin said. “The park was flooded, but finally sucked much faster.”

The long wetland system of the park includes the bushes of water plants that remove pollutants from the water.

(Sakchai Lalit / Associated Press)

Although it was just a few steps away, he now pointed to the pond without the bad smell of the channel or the greasy brightness. Yusufçuklar hill on the hill – a common sign, the water is clean, he said.

Chatchanin acknowledged that a park alone could not solve Bangkok’s water problems. However, his modest success can at least encourage cities to rethink their relations with water.

“People want fast answers, C Chatchanin said. “But hiding the problem is not a solution. You cannot only lift your home on stylts or clean the water. Finally, everything comes back.”

The idea that cities should adapt to the floods, his studies with sponge cities had a lifelong concern of Kongjian Yu, who won the Prestige Oberlander International Landscape Architecture Award and the designer of New York Central Park, Frederick Law Olmsted.

Yu monitors his beginnings to experience close to a death he lives in as a child growing in the countryside of China.

When Yu, who was only 10 years old, found that he was suddenly sweeping with strong currents, he was playing on the banks of the river of his village, which was more voluminous because of his heavy monsoon rains.

It was the reeds and will of the river that saved him, slowed the water and gave him the chance to remove himself.

The work of Kongjian Yu made comparisons with Frederick Law, the designer of the Central Park of New York.

(Gilles Sabrié / Times for Times)

“My experience in these villages, my experience with the river and the creek taught me how to live with nature,” he said.

Later, Yu received a landscape ecology from Harvard University Design Institute and spent two years in Los Angeles in 1997 before returning to China.

He was horrified for rapidly lining the cities of the modernized country through concrete dams and channelized waterways, to write to the local mayors, to warn the risks of this approach and to defend yeniden re -wrapping natural water systems ”.

Yu sponge cities follow three principles: protecting, slowing down and embracing water, Yu said. “This means to fix all unnecessary concrete and pavement.”

At first, his ideas found a small number of sympathetic ears. Some people sent a letter to the Communist Party, the Communist Party, who claims to be a spy a spy sent to destroy the Chinese infrastructure.

However, in 2012, when the violent floods in Beijing destroyed thousands of houses and some killed 79 people who were caught unprepared on the street, things changed.

A man uses a signal to signal the drivers passing through the streets under the flooded streets after a violent rain in Beijing. Flood encouraged Chinese leader Xi Jinping to adopt Yu’s “Sponge City” philosophy as a national agenda.

(Associated Press)

“All kinds of paradigm change, you need a crisis, Yu said. “People who died on the street – that was the critical point.”

The floods encouraged Chinese leader Xi Jinping in 2015 to adopt Yu’s sponge city philosophy as a national agenda. Since then, the government has promised more than 28 billion dollars to finance the 33,000 sponge city projects in 90 cities, and aimed to capture and reuse at least 70% of rain water by 2030.

According to the Ministry of Housing and Urban-Rural Development, more than 40,000 sponge City projects were completed by 2020 and contributed to the recycling of about 3.8 trillion gallon rainwater that year. The Ministry said that this amount is equal to about one -fifth of China’s annual urban water source.

Many, such as Bangkok’s Benjakitti Park, are wetlands for urban floods. Others serve as a Mangrov Forest built on the banks of a river in Sanya, the tropical southern city of Hainan Island, a natural buffer against rising sea levels and a natural buffer against coastal erosion.

“The idea is not to build a very close to water to create a buffer zone,” Yu said. “Instead of building a wall, we let water go in.”

Women stand near the ponds and water plants in the “Fish Tail” sponge park, built on an old coal ash in Nanchang in Jiangxi, North-Middle China.

(NG Han Guan / Associated Press)

Yu said that this approach has made sponger City projects uncomplicated and low -cost compared to traditional solutions.

For example, Benjakitti Park cost $ 20 million and was built by the Thai army, which had little experience in the surrounding landscape. Yu scribbled the design on a napkin during his flight to Bangkok to meet Chatchanin, and at least in theory he kept just enough to reach only a single excavator.

Nevertheless, the program did not have difficulty.

Wetlands are usually reproductive areas for mosquitoes. And while the cost of the projects of local governments was expected to increase up to 80%, it was slow to make more needed investments from the private sector. Meanwhile, critics said that some of the best sponge cities, such as Zhengzhou in Henan, China, are still destructive floods.

“If a city cannot cope with a flood, it is not spongy enough,” Yu said.

“Ultimately, it’s not about getting rid of every piece of concrete. To combine gray and green – about raising the current model.”

Since 2006, Singapore has been transforming its own waterways and reservoirs into public parks that absorbs rainwater, an initiative known as the active, beautiful, clean water (ABC Waters) program.

In the Netherlands, the government, a famous flood -oriented country, has tried with a softer approach and strategically allowed its rivers to float in certain areas to save others.

In LA, there has also been an increasing awareness that the region that can be stored and reused, otherwise, has been delayed for change of the region’s own impossible flood control system.

La region, which can be caught by about 490,000 acres of rainwater in an area containing Long Beach and Anaheim, ranks 19 out of 2,645 urban areas in the West with the potential of rainwater flow and 2,645 urban areas throughout the country. Pacific Institute Report last year.

The pedestrians uses the Los Angeles River Bikeway.

(Juliana Yamada / Los Angeles Times)

Among the efforts to make the city sponge – and therefore less dependent on imported water, the voting measure of La County voters in 2018 W.

The program receives a real estate tax on non -impermeable surfaces for municipal rain water capture projects to provide a grant of approximately $ 300 million annually.

The purpose of the program is to catch 98 billion gallons per year. Experts, upper La Watershed’de such projects at the same time can help prevent water raid, he said.

However, the authorities estimated that achieving this goal will take decades and progress is slow.

According to the report of Los Angeles Waterkeeper, a local guard, only 30 acres of green space was added to the district in the first three years.

And the program has recently started to take the speed of approximately 1 billion dollars to 130 projects, but a member of the Group’s General Manager Bruce Reznik and Measure Working Committee, pointed out that there is a number of challenges that are not found in China’s central model.

These include slow, expensive bureaucratic processes related to the program, such as inadequate federal support and cleaning of contaminated project sites. He predicted that the projects needed by the district would cost about 50 billion dollars, and 10 times higher in the next 20 years.

“In terms of expenses, this is a question that most of us ask: why are these projects so expensive?” He said Reznik. Orum I understand that there is inflation, but human beings, the projects we think will be 10 million dollars are now 25 million dollars.

Private reporters Chalida Ekvitthayavechnukul And Xin-yun Wu contributed to reporting from Bangkok and Taipei respectively.