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 persistent issues: flooding.
For Bangkok, a metropolis of 11 million sitting on low-lying swampland, the administration of its water has more and more turn into a matter of survival. With the capital dealing with extra frequent and excessive rainfall in addition to rising sea ranges because of local weather change, specialists have warned that total swaths of the town could also be underwater inside the subsequent few many years.
Los Angeles is aware of the right way 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 techniques just like the L.A. River, Chatchanin felt that Bangkok’s personal stormwater infrastructure had reached its tipping level.
An aerial view exhibits pathways by the Benjakitti Park in Bangkok.
(Krit Phromsakla Na Sakolnakorn / Related Press)
Many years of fast city growth have encased the town with impermeable concrete surfaces that hinder the pure drainage of water. Consequently, 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 recurrently overwhelmed.
“As a result of the canal water mixes with public sewage, the water high quality is actually unhealthy,” Chatchanin stated. “The park mission was a chance to soak up and clear this water.”
To design the brand new house, 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 metropolis” mannequin of city water administration.
The concept is that, not like “grey” 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 will probably flip into runoff that pollutes streets and strains drainage techniques.
Their profitable design, which was opened to the general public three years in the past, was realized in simply 18 months and displays the concept such city water administration techniques also can present worthwhile aesthetic and leisure advantages to communities.
Right this moment, the previous brownfield is a well-liked bird-watching spot. It options forested walkways alongside badminton and pickleball courts inbuilt 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, an extended system of wetlands containing thickets of aquatic crops 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 coming into permeable earth as a substitute of being blocked by concrete helps to replenish pure underground reservoirs that profit people and the setting.
“Final yr we had actually heavy rains,” Chatchanin stated. “The park additionally flooded however finally absorbed it far more rapidly.”
The park’s lengthy system of wetlands incorporates thickets of aquatic crops that take away pollution from the water.
(Sakchai Lalit / Related Press)
She pointed to the pond, which now not had the foul odor or the oily sheen of the canal regardless of being only a few steps away. Dragonflies buzzed overhead — a typical 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.
“Individuals need quick solutions,” Chatchanin stated. “However hiding the issue isn’t any resolution. You’ll be able to’t simply increase your home on stilts, or flush out the water. All of it comes again ultimately.”
The concept that 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 celebrated Oberlander Worldwide Panorama Structure Prize and comparisons to Frederick Legislation Olmsted, the designer of New York’s Central Park.
Yu traces its beginnings to a near-death expertise he had as a toddler 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 standard because of heavy monsoon rains, when he instantly 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 drag himself out.
Kongjian Yu’s work has earned him comparisons to Frederick Legislation Olmsted, the designer of New York’s Central Park.
(Gilles Sabrié / For The Occasions)
“My expertise in these villages, my expertise with the river and the creek, taught me the right way to stay with nature,” he stated.
Later, Yu earned a panorama ecology diploma from Harvard College’s Graduate Faculty 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 strategy and advocating as a substitute for “rewilding pure water techniques.”
“Sponge cities observe three ideas: retain, decelerate and embrace water,” Yu stated. “Which means eradicating all pointless concrete and pavement.”
At first, his concepts discovered few sympathetic ears. Some folks, he recalled, despatched letters to the Communist Social gathering claiming he was “a spy from the U.S. despatched to demolish Chinese language infrastructure.”
However issues modified in 2012, when extreme flooding in Beijing destroyed hundreds of properties and killed 79 folks, 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 metropolis” philosophy as a nationwide agenda.
(Related Press)
“Each kind of paradigm shift, you want a disaster,” Yu stated. “Individuals dying on the street — that was the important level.”
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 not less than 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, based on 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 towards saltwater intrusion and coastal erosion from rising sea ranges.
“The concept is to not construct too near the water in an effort to create a buffer zone,” Yu stated. “As a substitute of constructing a wall, we enable the water to come back in.”
Girls cease close to ponds and water crops on the “Fish Tail” sponge park that’s constructed on a former coal ash dump website in Nanchang in north-central China’s Jiangxi province.
(Ng Han Guan / Related Press)
This strategy, stated Yu, has made sponge metropolis initiatives uncomplicated and low-cost in contrast with standard options, deployable nearly wherever.
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, holding it easy sufficient to be achievable — not less than in concept — 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 price 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 metropolis can’t deal with a flood, which means it’s not spongy sufficient,” Yu stated.
“Finally, it’s not about eliminating every bit of concrete. It’s about combining grey and inexperienced — upgrading the present mannequin.”
Since 2006, Singapore has been turning its personal waterways and reservoirs into public parks that additionally take up stormwater, an initiative referred to as the Lively, Stunning, Clear Waters (ABC Waters) Programme.
Within the Netherlands, a flood-prone nation well-known for mastering the artwork of holding water out with methods like land reclamation, the federal government has additionally experimented with a softer strategy, 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 realm’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 obtainable to be captured a yr in an space that features Lengthy Seaside and Anaheim, the L.A. space ranks first within the West in stormwater runoff potential and, nineteenth out of two,645 city areas nationwide, based on a Pacific Institute report final yr.
Pedestrians use the Los Angeles River Bikeway.
(Juliana Yamada / Los Angeles Occasions)
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 supply round $300 million a yr in grants for municipal stormwater seize initiatives.
The intention of this system is to seize 98 billion gallons yearly. Specialists have stated that initiatives like this within the higher L.A. watershed may concurrently assist stop flooding downstream.
But officers have estimated that it’s going to take many years to attain this purpose, and progress has been gradual.
Simply 30 acres of inexperienced house had been added to the county in its first three years, based on a report by Los Angeles Waterkeeper, a neighborhood watchdog.
And though this system has just 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 assist and the gradual, pricey bureaucratic processes concerned with this system, akin to cleansing up contaminated mission 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.
“When it comes to bills, that’s a query numerous us are asking: Why are these initiatives so costly?” Reznik stated. “I get that there’s inflation, however man, initiatives we thought had been going to be $10 million are actually $25 million. I believe we’ve received to determine ways in which we are able to streamline some of these items.”
Particular correspondents Chalida Ekvitthayavechnukul and Xin-yun Wu contributed reporting from Bangkok and Taipei, respectively.
