On a warm July day, Katherine Rose took a metal bar and pushed it under a concrete slab. Rose, director of communications for Depave – a non-profit organization in Portland, USA – was sweating profusely from the heat, but she was not going to let herself be defeated by a heavy piece of cement.
The large block of urban crust in front of her was regarding to move. Using a little force with the metal bar, Rose was able to remove the concrete rectangle and place it outside the pavement.
“It’s like freeing the land,” he says.
She remembers that in the middle of last year she and 50 other volunteers removed regarding 1,670 square meters of concrete near a local church.
“It’s like making a dream that we all have come true,” he says.
That dream is to bring nature back to us.
The idea of depaving is simple: replace as much of the concrete, asphalt, or other forms of urban construction with plants and soil.
In the city of Portland it has been done since 2008, when Depave was founded.
What the creators of this program say is that unpaving allows something very simple: that the water that falls in cities can be absorbed by the earth and, in this way, flooding is avoided.
It also allows wild plants to grow in urban space and, by planting more trees, more shade can be produced, which in turn protects city dwellers from solar radiation and heat waves.
Not to mention that expanding the green area in a city can help people’s mental health.
City of LeuvenDepaving is a process that serves so that the land can be used to plant gardens or green areas.
Beyond volunteers
But if unpaving can truly become a solution, it will have to expand far beyond what a few dozen volunteers can do.
With the climate change crisis worsening, cities and entire regions have begun to adopt depaving as part of their strategy to adapt to the new times.
It’s time, some say, to start removing concrete from streets more effectively to create better spaces for nature.
For that reason, every time Rose walks through a city she can’t help but notice where the asphalt might be removed to place some plants.
“I constantly want to do more. It is impossible not to see the spaces to do it,” she says.
She notes that her group has managed to depave regarding 33,000 square meters of asphalt in Portland since 2008 (which is the equivalent of four and a half football fields).
And he describes the work as “fun,” because it brings together many volunteers, who receive a safety course before starting the task.
Green Venture is another non-profit organization operating in Ontario, Canada, inspired by the work being done in Portland.
Giuliana Casimirri, its executive director, says that she and her colleagues have managed to insert small gardens with native trees in a district of the city of Hamilton.
“Before they were places you passed quickly and now they are places where you can stop and start chatting. Or just stop and read the newspaper,” she explains.
In Hamilton, flooding can cause sewage to mix with tributaries of Lake Ontario, which is the main source of drinking water for the city.
The idea of Green Venture and other local organizations is to reduce the chances of that happening, Casimirri says.
His vision is a key strategy for the city.
City of LeuvenDepaving makes it possible to create small green spaces within cities.
Indeed, studies have shown that impervious surfaces such as concrete increase flood risks in urban areas.
Rose notes that his team’s efforts in Portland have resulted in regarding 83 million liters of rainwater annually being diverted from entering the city’s drainage system.
In Leuven, Belgium, Baptist Vlaeminck, the leader of the local climate change adaptation project, estimates that in 2023 alone the removal of 6,800 square meters of concrete allowed 1.7 million liters of water to be absorbed by the earth when it falls. the rains.
“With climate change, storms are going to increase, so unpaving is not just something nice, it is a necessity,” says Casimirri.
The question now is whether the city authorities are aware of this.
In many parts of the world, depaving is seen as a marginal activity.
“We are going to need a scale of investment with many more zeros to continue,” Thami Croeser, of RMIT University in Melbourne, Australia, told the BBC.
Mentality change
Community efforts to free streets are “fantastic,” says Croeser, but he adds that the ideal is that, instead of unpaving and greening, a new way of building urban infrastructure is sought.
“The same planning and resources are needed as planning a new train line,” he points out.
In Europe, at least, some cities have begun to depave consistently.
London residents, for example, are being invited to reclaim green in the soil of their gardens.
And Leuven, in Belgium, says it is embracing the idea of large-scale depaving.
The Spaanse Kroon district of this city, where regarding 550 people live, is one of the most recent targets of the local initiative to regenerate green spaces.
The plans involve removing a significant volume of asphalt from residential areas and forcing cars to share the road with pedestrians and cyclists.
“We are expanding the program, now we are creating a team dedicated to depaving,” says Vlaeminck.
Projects like this must meet the needs of everyone in the city, he points out.
Vlaeminck says that to help those with vision or mobility problems, unused areas of the road or sidewalks are given priority when depaving, while leaving an area of more than one meter on the sidewalks themselves. so that people have enough space to move.
Existing pavement that is not removed is also renewed or repaired to ensure that there are no potholes or unevenness.
Those responsible for Depave in Portland and Green Venture in Ontario say they work with communities so that accessibility requirements are met.
Casimirri is referring to a recent project that replaced damaged and dilapidated concrete with bushes and graded paths in between.
Among the initiatives promoted in Leuven is the “debris taxi.”
This is a small truck that is sent to the house of those who have debris or pieces of concrete that they have taken from their gardens, so that they can easily throw away the remains.
The material is then not discarded but reused, says Vlaeminck, adding that Leuven has allocated several million euros to finance removal and renaturalization projects like this one.
And there is more. Since January 2024, promoters of this initiative have had to demonstrate that any rain that falls on new or significantly renovated homes can be reused on site or filtered into the property’s garden, rather than accumulating and causing flooding.
If developers cannot demonstrate that their designs are prepared for extreme rainfall they will not be approved, explains Vlaeminck.
France is also making depaving official, says Gwendoline Grandin, an ecologist at the Île-de-France Regional Biodiversity Agency.
At the national level, the French government has allocated nearly US$540 million to urban ecology projects. This includes removing pavement but also installing green walls and roofs, for example.
Part of the motivation is to make towns and cities more resilient to summer heatwaves, which have severely affected large areas of France in recent years.
Some of the projects underway are of significant size, such as a former parking lot near a forest in the Paris region.
An area of 45,000 square meters has been depaved, of what was previously a space of asphalt and concrete intertwined with grass.
Once the cement is removed, the leveled land is being remodeled to introduce slopes and ravines that trap water and soon the entire area will also be planted.
Getty Images Much of the pavement that is removed can be reused in other projects.
In Croeser’s home city of Melbourne, he and his colleagues have studied the potential space available to regenerate with gardens and green walls.
In a 2022 study, they simulated the impact based on different scenarios, the most ambitious of which involved eliminating half of the city’s outdoor parking spaces, regarding 11,000..
Croeser argues that there is enough off-street parking available in Melbourne to ensure that no one is left without a place to leave their vehicle, but that those indoor parking spaces should be made public and accessible.
“The basic principle is that there is no net loss of access to parking,” he says.
“And we obtain between 50 and 60 hectares of green spaces available, which keep the city cool and prevent flooding,” he points out.
It may seem unlikely that small pockets of green scattered here and there in a big city like Melbourne would significantly benefit wildlife, but Croeser says those patches of habitat are crucial.
According to him, these spaces can allow species to move and develop in an environment that, ultimately, is quite different from the one they have been in for years.
In their 2022 study of paving in Melbourne, Croeser’s team included modeling that suggested a modest increase in vegetation might allow species like the blue-banded bee to roam a much larger urban area than they previously occupied.
Rose agrees with Croeser that for depaving to change the world, entire cities, and even entire countries, will have to fully embrace the proposal.
But he emphasizes that to get to that point, communities must express their support for the idea.
“It all starts with people putting pressure on their government and starting these conversations at a small, local level,” he says.
“That’s how it takes hold.”
BBC
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