In 2019, when the Thai authorities introduced plans to show an deserted tobacco manufacturing unit within the nation’s smoggy capital right into a public park, Bangkok-based panorama architect Chatchanin Sung noticed a chance to deal with one other of the town’s power issues: flooding.
For Bangkok, a metropolis of 11 million sitting on low-lying swampland, the administration of its water has more and more develop into a matter of survival. With the capital dealing with extra frequent and excessive rainfall in addition to rising sea ranges as a result of local weather change, specialists have warned that whole swaths of the town could also be underwater throughout the subsequent few many years.
Los Angeles is aware of learn how to climate a disaster — or two or three. Angelenos are tapping into that resilience, striving to construct a metropolis for everybody.
Like Los Angeles, the place intensifying droughts and floods have revealed limitations of standard flood management programs just like the L.A. River, Chatchanin felt that Bangkok’s personal stormwater infrastructure had reached its tipping level.
An aerial view reveals pathways by the Benjakitti Park in Bangkok.
(Krit Phromsakla Na Sakolnakorn / Related Press)
Many years of fast city improvement have encased the town with impermeable concrete surfaces that hinder the pure drainage of water. In consequence, the town’s community of over 1,600 city canals, which had been as soon as used for transporting items and folks however now primarily act as stormwater channels, are often overwhelmed.
“Because the canal water mixes with public sewage, the water quality is really bad,” Chatchanin mentioned. “The park project was an opportunity to absorb and clean this water.”
To design the brand new area, a 102-acre growth to the pre-existing Benjakitti Park, Chatchanin partnered with Kongjian Yu, a Beijing-based panorama architect who has lengthy advocated what is called a “sponge city” mannequin of city water administration.
The thought is that, not like “gray” infrastructure, which is designed to flush water away as rapidly as doable, cities like Bangkok can mitigate flood threat just by making its surfaces extra absorbent like a sponge, capturing stormwater earlier than it could actually flip into runoff that pollutes streets and strains drainage programs.
Their successful design, which was opened to the general public three years in the past, was realized in simply 18 months and displays the concept that such city water administration programs also can present priceless aesthetic and leisure advantages to communities.
At present, the previous brownfield is a well-liked bird-watching spot. It options forested walkways alongside badminton and pickleball courts in-built repurposed cigarette warehouses, all of the whereas capturing and cleansing water.
Individuals take a relaxation at Benjakitti Park in Bangkok.
(Sakchai Lalit / Related Press)
Fed by a close-by canal, a protracted system of wetlands containing thickets of aquatic vegetation removes pollution from the water because it winds across the park’s perimeter, releasing what’s left into a big pond dotted with small islets.
This, alongside the park’s porous panorama and extra retention ponds, allow it to seize 23 million gallons of stormwater throughout Bangkok’s rainiest months. The water that’s getting into permeable earth as an alternative of being blocked by concrete helps to replenish pure underground reservoirs that profit people and the atmosphere.
“Last year we had really heavy rains,” Chatchanin mentioned. “The park also flooded but eventually absorbed it much more quickly.”
The park’s lengthy system of wetlands accommodates thickets of aquatic vegetation that take away pollution from the water.
(Sakchai Lalit / Related Press)
She pointed to the pond, which not had the foul odor or the oily sheen of the canal regardless of being only a few steps away. Dragonflies buzzed overhead — a standard signal, she famous, that the water is clear.
Chatchanin acknowledged that one park alone can’t repair Bangkok’s water points. However its modest success would possibly, on the very least, encourage cities to rethink their relationship to water.
“People want fast answers,” Chatchanin mentioned. “But hiding the problem is no solution. You can’t just raise your house on stilts, or flush out the water. It all comes back in the end.”
The concept cities have to adapt to — not outrun — their floods has been a lifelong preoccupation of Kongjian Yu, whose work with sponge cities has earned him the distinguished Oberlander Worldwide Panorama Structure Prize and comparisons to Frederick Regulation Olmsted, the designer of New York’s Central Park.
Yu traces its beginnings to a near-death expertise he had as a baby rising up in rural China.
On the time simply 10 years outdated, Yu had been taking part in on the banks of his village’s river, which was extra voluminous than ordinary as a result of heavy monsoon rains, when he out of the blue discovered himself being swept away by the highly effective currents.
What saved him had been the river’s reeds and willows, which slowed the water and gave him an opportunity to tug himself out.
Kongjian Yu’s work has earned him comparisons to Frederick Regulation Olmsted, the designer of New York’s Central Park.
(Gilles Sabrié / For The Instances)
“My experience in these villages, my experience with the river and the creek, taught me how to live with nature,” he mentioned.
Later, Yu earned a panorama ecology diploma from Harvard College’s Graduate College of Design and spent two years in Los Angeles working for SWA Group earlier than returning to China in 1997.
Dismayed that the quickly modernizing nation had lined its cities with concrete dams and channelized waterways, Yu started writing to native mayors, warning of the dangers of this method and advocating as an alternative for “rewilding natural water systems.”
“Sponge cities follow three principles: retain, slow down and embrace water,” Yu mentioned. “That means removing all unnecessary concrete and pavement.”
At first, his concepts discovered few sympathetic ears. Some individuals, he recalled, despatched letters to the Communist Occasion claiming he was “a spy from the U.S. sent to demolish Chinese infrastructure.”
However issues modified in 2012, when extreme flooding in Beijing destroyed hundreds of houses and killed 79 individuals, a few of whom had been caught off-guard on the street.
A person makes use of a signboard to sign motorists driving by flooded streets following a heavy rain in Beijing. Flooding prompted Chinese language chief Xi Jinping to undertake Yu’s “sponge city” philosophy as a nationwide agenda.
(Related Press)
“Every sort of paradigm shift, you need a crisis,” Yu mentioned. “People dying in the street — that was the critical point.”
The floods prompted Chinese language chief Xi Jinping to undertake Yu’s sponge metropolis philosophy as a nationwide agenda in 2015. Since then, the federal government has pledged greater than $28 billion to assist fund over 33,000 sponge metropolis initiatives in 90 cities, aiming to have them seize and reuse a minimum of 70% of their rainwater by 2030.
By 2020, over 40,000 sponge metropolis initiatives had been accomplished nationwide, contributing to round 3.8 trillion gallons of rainwater being recycled that yr, in response to the Ministry of Housing and City-Rural Growth. The ministry famous that this quantity was equal to about one-fifth of China’s annual city water provide.
Many, like Bangkok’s Benjakitti Park, are wetlands designed to deal with city flooding. Others, like a mangrove forest constructed on the banks of a river within the tropical southern metropolis of Sanya on Hainan Island, act as a pure buffer in opposition to saltwater intrusion and coastal erosion from rising sea ranges.
“The idea is to not build too close to the water in order to create a buffer zone,” Yu mentioned. “Instead of building a wall, we allow the water to come in.”
Ladies cease close to ponds and water vegetation on the “Fish Tail” sponge park that’s constructed on a former coal ash dump web site in Nanchang in north-central China’s Jiangxi province.
(Ng Han Guan / Related Press)
This method, mentioned Yu, has made sponge metropolis initiatives uncomplicated and low-cost in contrast with standard options, deployable nearly anyplace.
Benjakitti Park, for instance, value $20 million and was constructed by the Thai military, which had little expertise in environmental landscaping. Yu scribbled the design on a serviette throughout his flight to Bangkok to satisfy Chatchanin, preserving it easy sufficient to be achievable — a minimum of in idea — with solely a single excavator.
Nonetheless, this system hasn’t been with out challenges.
Wetlands are sometimes breeding grounds for mosquitoes. And with native governments anticipated to foot as much as 80% of the associated fee for his or her initiatives, much-needed investments from the personal sector have been gradual to materialize. In the meantime, critics have identified that a few of China’s most touted sponge cities, like Zhengzhou in Henan province, have nonetheless skilled devastating floods.
“If a city can’t handle a flood, that means it’s not spongy enough,” Yu mentioned.
“Ultimately, it’s not about getting rid of every piece of concrete. It’s about combining gray and green — upgrading the current model.”
Since 2006, Singapore has been turning its personal waterways and reservoirs into public parks that additionally soak up stormwater, an initiative often known as the Energetic, Lovely, Clear Waters (ABC Waters) Programme.
Within the Netherlands, a flood-prone nation well-known for mastering the artwork of preserving water out with methods like land reclamation, the federal government has additionally experimented with a softer method, strategically permitting its rivers to flood in sure areas in an effort to spare others.
In L.A., too, there was a rising consciousness that the world’s metropolis’s personal impermeable flood management system, which discards billions of gallons of rainwater that may in any other case be saved and reused, is overdue for change.
With round 490,000 acre-feet of stormwater out there to be captured a yr in an space that features Lengthy Seashore and Anaheim, the L.A. space ranks first within the West in stormwater runoff potential and, nineteenth out of two,645 city areas nationwide, in response to a Pacific Institute report final yr.
Pedestrians use the Los Angeles River Bikeway.
(Juliana Yamada / Los Angeles Instances)
Among the many efforts to make the town spongier — and due to this fact much less depending on imported water — is the Protected Clear Water Program, which L.A. County voters accredited in 2018 as poll Measure W.
This system levies a property tax on impermeable surfaces to offer round $300 million a yr in grants for municipal stormwater seize initiatives.
The purpose of this system is to seize 98 billion gallons yearly. Consultants have mentioned that initiatives like this within the higher L.A. watershed might concurrently assist stop flooding downstream.
But officers have estimated that it’ll take many years to attain this aim, and progress has been gradual.
Simply 30 acres of inexperienced area had been added to the county in its first three years, in response to a report by Los Angeles Waterkeeper, an area watchdog.
And though this system has lately begun to choose up tempo, with round $1 billion allotted throughout 130 initiatives, Bruce Reznik, the group’s govt director and a member of the Measure W scoring committee, pointed on the market are a number of challenges not current in China’s centralized mannequin.
Amongst them are scant federal help and the gradual, expensive bureaucratic processes concerned with this system, equivalent to cleansing up contaminated challenge websites and getting permits. He estimated that the initiatives the county wants will value round $50 billion, 10 instances what Measure W funding can present over the following 20 years.
“In terms of expenses, that’s a question a lot of us are asking: Why are these projects so expensive?” Reznik mentioned. “I get that there’s inflation, but man, projects we thought were going to be $10 million are now $25 million. I think we’ve got to figure out ways that we can streamline some of this stuff.”
Particular correspondents Chalida Ekvitthayavechnukul and Xin-yun Wu contributed reporting from Bangkok and Taipei, respectively.
