(CNN) Cities’ relationship with water is a delicate balance. Too little leads to parched landscapes and water shortages; too much can cause deadly flooding, washing away homes, lives and livelihoods.
Last year, severe flooding wreaked havoc around the world, including in Nigeria, Pakistan and Australia. And it’s forecast to be even worse. By the end of the century, parts of Asia’s largest cities are expected to be under water. Sea level rise on US coasts is expected to be 10 to 12 inches by 2050.
To protect themselves, cities focus on keeping water out and often turn to concrete: they build walls, dams and other “grey infrastructure”.
“This approach works well when it is possible to predict the magnitude and quantity of flooding events, but has serious limitations in relation to current climate unpredictability,” said Elisa Palazzo, Senior Lecturer at UNSW Sydney’s School of Built Environment. to CNN.
As the climate crisis continues to threaten cities and reshape coastlines, it has prompted some to take a different tack. These vulnerable urban areas seek to work with water rather than against it, incorporating it into the fabric of the city—soaking it up when there’s too much; keep if there is not enough.
Whether these efforts can be scaled up fast enough to meet cities’ enormous climate challenge is not yet clear. But they show the possibilities if cities stop seeing water only as a threat that concrete can control.
Here’s how five cities are trying to regain their relationship with water.
Bangkok, Thailand: ‘Monkey Cheeks’ Parks
Chulalongkorn Centenary Park in Bangkok.
Built on the floodplains of the Chao Phraya River, Bangkok is incredibly prone to flooding. In 2011, devastating floods inundated the city, killing hundreds of people.
To add to the pressure, the city of nearly 11 million people, which sits about 1.5 meters above sea level, is sinking as water levels rise in the Gulf of Thailand due to growing urbanization.
Thai architect Kotchakorn Voraakhom, who founded landscape architecture firm Landprocess, has devoted much of her work to understanding how to better plan for floods, asking, “What if we could design cities to work with nature , instead of against them?”
“Climate change is sinking cities, and our current infrastructure makes us even more vulnerable to severe flooding,” she told CNN.
One of their solutions for Bangkok is Centenary Park at Chulalongkorn University in central Bangkok — a rare green space in a city that lacks them.
The park is designed to work with water, not against it.
Completed in 2017, the 11-hectare (45,000-square-meter) park is designed to work with and capture water. Built on a slope, it can channel water through its gardens and artificial wetlands and then into a retention pond.
Perhaps the most ingenious feature lies out of sight. Below the park are underground tanks that can hold 160,000 gallons of water. In total, the park can hold up to a million gallons of water.
The concept for the park came from the idea of monkey cheeks, Voraakhom told the New York Times. Monkeys use their cheeks to store food to eat when hungry; The park wants to achieve this with water.
Green spaces can also help reduce air pollution and reduce the urban heat island effect, where dense, concrete cities trap heat. While Centenary Park is just a tiny part of town, Voraakhom said it’s an example of what can be done.
Beijing, China: Sponge Cities
Yongxing River sponge city project before redevelopment. Yongxing River sponge city project after redevelopment.
Suffering from both floods and droughts, China has long been a proponent of “sponge cities”. The idea is to enable cities to soak up and retain excess water with designs that focus on nature, including gardens, green roofs, wetlands and permeable sidewalks – allowing water to both sink into the ground and out can flow.
In 2015, the government announced a pilot project involving 16 sponge cities, sparked in part by severe floods that hit Beijing in 2012, killing nearly 80 people and causing widespread damage. Since then many more projects have been added.
“All cities try to resist water like an enemy,” said architect and professor Kongjian Yu, founder of design firm Turenscape and pioneer of sponge cities. The goal of sponge cities is to “give water more space,” he told CNN.
Yongxing River Park in Beijing is one of Yu’s many sponge city projects. Turenscape transformed the former concrete spillway into a “sponge river” used to manage floods and filter rainwater.
A network of trails connects the park, which is filled with plants and trees, including willow, crab apple, and hawthorn trees. It also has playgrounds for children as well as a sports field.
As sponge cities spread across China, there have been some questions about their ability to cope with heavier rainfall and storms made worse by climate change. In 2021, the city of Zhengzhou in Henan Province, which is part of the Sponge City Initiative, experienced devastating rains that killed nearly 300 people.
But for Yu, sponge cities offer a needed correction to the mistakes made in growing cities, including the damage and destruction of rivers and wetlands, and heavy reliance on concrete.
Amsterdam, Netherlands: Turning houses into boats
A community of floating houses in Schoonschip, Amsterdam.
The Netherlands, about a third of which lies below sea level, tries to work with the water by literally building on it.
Rotterdam is home to the world’s first floating dairy, which opened in 2019, as well as floating parks made from waste and even a floating office building.
And in recent years, the idea of floating houses has slowly gained traction.
Architects Space&Matter have designed a community of 30 waterfront houses in the northern Amsterdam district of Schoonschip. Construction was completed in 2021 and today houses more than 100 residents.
“Thinking behind floating houses is logical when you live in a city like Amsterdam. Water and land are intertwined,” said Jeroen Dellensen, one of the three founders along with Jaspar Jansen and Chris Collaris of the design firm i29, which designed one of the houses in the community.
Built with timber frame and insulated with burlap and straw, the houses are equipped with heat pumps and solar panels. Roof gardens are designed to help them cool and absorb rainwater in summer.
A flexible walkway connects the houses to each other and to the property. They are designed to rise and fall with the ebb and flow of the water.
“Schoonschip aims to serve as a prototype for how to deal with depressed coastal and delta regions. Rather than fighting rising sea levels, we should adapt and embrace water as an urban condition,” said Tom Kolnaar, communications manager at Space&Matter CNN.
The community is designed to withstand changing water levels over the next few decades, but it will require additional infrastructural support to withstand the much higher sea levels projected beyond, Kolnaar said.
The Maldives: A city modeled after a brain coral
An illustration of the floating city of Maldives.
Few countries are more at risk from the climate crisis than the Maldives. The vast majority of the archipelago of more than 1,000 islands in the Indian Ocean is less than a meter above sea level.
The risk of flooding coupled with the need for more housing is driving a government project – in partnership with developer Dutch Docklands – to build a new floating city.
It’s kind of a “techno city… [but] with the look and feel of an old fishing village from the Maldives,” Koen Olthuis, one of the founders of Waterstudio, the company that designed the city, told CNN.
Located on a lagoon about 10 minutes by boat from the capital Male, the city will consist of a series of floating units that will be built on site and towed into the water. They will be fixed to the seabed on telescopic stilts that will allow the city to rise and fall with the waves and cope with rising sea levels.
Olthuis said the environmental impact has been rigorously assessed. The design is based on a brain coral and its ability to “strike a balance between space and openness,” he explained, adding that the city would look like such a coral from above. The goal is a dense city that can accommodate people while still allowing enough sunlight to reach the seabed below. Artificial coral reefs will be installed below the city to create coral ecosystems.
Construction will begin in earnest towards the end of this year and is expected to be completed by early 2028.
Floating cities have been criticized for offering overly expensive housing solutions, but Olthuis said affordability is a requirement set by the Maldives government. The goal is for 90% of the residents to be resident in the Maldives and for the houses to be priced at the same price level as similar properties in Male, he said.
“There’s a growing need for these kinds of developments,” said Olthuis, who said his company has received a lot of inquiries about floating cities: “Not because people love the idea of living on water, but because there’s a solution for… the need for space and security from the impacts of climate change.”
Copenhagen, Denmark: building a huge “climate park”
Enghaveparken, a “climate park” in Copenhagen
In 2011, Copenhagen experienced a cloudburst – a very sudden and destructive rainstorm that in a matter of hours unleashed months of rain, leaving parts of the city three feet under water. Damage was extensive and estimated at around $1 billion.
The disaster has boosted the city’s climate plans. One of his answers is Enghaveparken – a huge “climate park”.
The park, which dates back to 1928, was redesigned by the architectural firm Tredje Natur (Third Nature). “It was kind of a catch 22 situation,” Fleming Rafn, a founding partner at Tredje Natur, told CNN. They needed to figure out how to preserve the park’s heritage while preparing it for a future of more extreme climate events.
The newly designed park, located at the foot of a hill, is based on the idea of water chambers.
A concrete hockey pitch has been lowered 3 meters and will be the starting point for flood containment. After the courtyard fills, water is allowed to flow to a sunken rose garden and eventually the lake. The park also has underground pools that collect rainwater from the neighborhood.
A perimeter wall around the park will hold back the water and was built so all of the historic trees could stay where they were, Rafn said.
Artist’s rendering of the flooded ball court.
During extreme 100-year events, the park’s entire 35,000 square meters (380,000 square feet) can be filled with water from end to end, where it can be contained until flooding subsides enough for the water to be discharged into sewers can. The park can handle around 6 million gallons.
The aim is to reconnect people with nature and the effects of the climate crisis, said Rafn. “It’s so difficult for us to understand the climate and our own relationship to it, and how do we as individuals actually participate in something that’s so abstract, and I think making it tangible is a huge promise to it.” to make it a down-to-earth discussion.”