For decades, modern cities were built around the same idea: more roads, more parking lots, more concrete, and more asphalt. These hard surfaces supported rapid urban growth and made transportation easier, but they also disrupted one of nature’s oldest cycles. Instead of soaking into the ground, rainwater now rushes across impermeable surfaces, overwhelming drainage systems, increasing flood risks, intensifying urban heat, and preventing groundwater from being naturally replenished.
A review by the United States Environmental Protection Agency found that permeable pavements can reduce stormwater runoff by as much as 90% under certain conditions, although performance depends on rainfall, soil characteristics, design, and maintenance.
Today, however, cities around the world are rethinking their relationship with water. From community-led depaving projects in Portland to rain-sensitive neighbourhoods in Utrecht, greener schoolyards in Paris, and China’s ambitious Sponge City Program, communities are embracing a wide range of nature-based solutions that allow rainwater to soak into the ground, support vegetation, reduce flooding, and cool urban environments. Some remove unnecessary pavement, while others rely on permeable surfaces, rain gardens, wetlands, green roofs, or underground infiltration systems.
Although each approach is different, they all share the same goal: working with nature rather than against it. Together, these initiatives illustrate a growing shift in urban design—one that restores natural water cycles while creating healthier, more resilient, and more livable cities for both people and wildlife.
Portland, Oregon: A Grassroots Movement Inspiring the World
Some of the world’s most inspiring environmental transformations don’t begin with massive government programs. They begin with neighbors picking up shovels together.
That is exactly the spirit behind Depave, a Portland-based nonprofit organization that has spent nearly two decades helping communities remove unnecessary asphalt and replace it with thriving green spaces. Since its establishment in 2008, Depave has worked with schools, faith organisations, businesses, residents and municipal partners. It has also trained or advised local depaving groups across the United States, Canada and elsewhere.
One of the organization’s most substantial recent projects is at Morning Star Church in Northeast Portland. Together with volunteers and community partners, Depave started transforming in 2023 a 15,000-square-foot parking lot into a vibrant climate-resilient landscape featuring rain gardens, native vegetation, shaded gathering spaces, and safe outdoor play areas for children. What was once an expanse of heat-absorbing pavement was reimagined as a place where both people and nature can flourish.
Removing the impermeable surfaces redirects rainwater into the site’s soil rather than sending it immediately into the drainage system. The newly planted trees and vegetation also provide shade and habitat as they mature.
Equally important is the project’s social impact. Every Depave initiative brings together volunteers of all ages, local residents, students, businesses, and community organizations to physically reshape their neighborhoods. These collaborative workdays foster a sense of ownership, strengthen social connections, and demonstrate that climate action is something everyone can participate in—not just governments or environmental experts. At the Morning Star project, for example, volunteers will gather again on August 8th to help water, weed, mulch, and prune the newly planted trees. This ongoing stewardship ensures that the site continues to thrive while reinforcing the idea that restoring nature is a long-term community commitment rather than a one-day event.
Utrecht, Netherlands: Treating Rain as a Valuable Resource
Utrecht provides a large-scale example of neighbourhoods designed around rainwater. In the Leidsche Rijn development, rainwater from roofs and smaller streets is channelled through grassed infiltration trenches, permeable paving and underground infiltration boxes, before flowing into canals. Many low-traffic roads and courtyards have permeable surfaces, and the planted trenches help to retain pollutants and return water to the soil.
In the redeveloped area around Utrecht’s central station, approximately 30,000 square metres of paved surface has been disconnected from the sewer network and connected to infiltration measures instead. This approach is part of the city’s wider efforts to combine water management with creating greener, healthier public spaces.
Utrecht’s commitment to sustainable planning goes hand in hand with an ambitious vision for quality of life. As the fastest-growing city in the Netherlands, it is also recognized as one of the country’s healthiest places to live and has consistently ranked among the world’s happiest cities in international well-being studies, including those referenced by the United Nations.
Utrecht’s approach treats rainwater as something to retain and use locally rather than remove as quickly as possible. In suitable locations, the same infrastructure can manage runoff, support vegetation and create more attractive public spaces.
Paris is Turning Schoolyards into Green Oases
In the heart of one of Europe’s most densely populated capitals, a quiet transformation is reshaping the everyday lives of thousands of children.
As part of its Resilience Strategy, adopted by the Paris City Council in 2017 to help the city respond to the environmental and social challenges of the 21st century, Paris launched the ambitious Oasis Schoolyards Program. Its mission is simple yet powerful: replace vast expanses of heat-absorbing asphalt with living landscapes that work in harmony with nature.
Since 2017, Paris has created 203 Oasis schoolyards and 5 Oasis nursery playgrounds. The city’s Climate Plan aims to extend the program across the capital by creating a total of 360 Oasis schoolyards by 2030.
Instead of predominantly asphalted playgrounds, children in Oasis schoolyards have access to trees, planted areas, natural materials, shade and more permeable surfaces. These redesigned spaces recreate a healthier relationship between cities, water, and nature while offering students a richer and more stimulating environment in which to learn and grow.
The benefits extend far beyond aesthetics. During increasingly frequent summer heatwaves, as France is going through this very summer, the redesigned yards are intended to function as local “cool islands”, using trees, vegetation, lighter or permeable surfaces and, in some cases, rainwater to moderate heat. The new green spaces also improve rainwater management, support urban biodiversity, encourage outdoor education, and create pockets of nature within densely built neighborhoods. Outside school hours, some Oasis schoolyards are even open to local residents, providing much-needed community cooling spaces during periods of intense heat.
This program therefore combines climate adaptation with children’s play, outdoor learning and, in some locations, public access outside school hours.
China’s “Sponge Cities”: Rethinking Urban Water Management
Perhaps one of the most ambitious urban transformations is taking place in China through the national Sponge City Program.
Inspired in part by the work of landscape architect Kongjian Yu, the initiative encourages cities to replace impermeable infrastructure with landscapes capable of absorbing, storing, filtering, and slowly releasing rainwater.
Permeable pavements, wetlands, green roofs, urban forests, rain gardens, and floodable parks all work together to mimic the natural water cycle.
Thirty cities were selected in 2015 and 2016 for the initial national pilot program. China’s planning objective has been for designated urban areas to absorb or use at least 70 % of rainfall on site, although implementation and performance vary considerably between cities.
Scientific research has demonstrated the potential of these approaches. A 2022 review of sponge-city projects found that rain gardens reduced total surface runoff by 25% to 69% and peak runoff by 12% to 71%. Researchers also emphasize that these systems require proper design and long-term maintenance to remain effective.
Sponge-city measures cannot eliminate flooding during extreme storms and must complement, rather than replace, conventional drainage and flood protection. They can nevertheless reduce runoff while creating greener and more useful urban spaces.
Sources: China Sponge City Program (Ministry of Housing and Urban-Rural Development); International Water Association; Nature-Based Solutions (2022); Kongjian Yu’s research on ecological infrastructure.
A Powerful Reminder That We Are Meant to Live in Harmony with Nature
Removing unnecessary pavement may seem like a small gesture. Yet, when multiplied across neighborhoods, cities, and countries, these actions reveal a growing awareness that healthy cities depend on healthy natural systems. They remind us that rainwater is not a problem to be rushed away, but a resource that can restore ecosystems, strengthen communities, and make urban environments more resilient.
The encouraging news is that this transformation is already underway. From Portland’s community-led depaving projects to Utrecht’s rain-sensitive neighborhoods, Paris’s green schoolyards, and China’s Sponge Cities, communities around the world are demonstrating that urban development and nature do not have to compete. Every schoolyard transformed into green space, every parking lot converted into a rain garden, and every street redesigned to let water return to the soil reflects a growing understanding that thriving cities and thriving ecosystems can flourish together in greater Unity and Harmony.
