What is a sponge city?
Sponges are known for their exceptional ability to absorb water. Sponge cities are designed to imitate the natural water cycle. The aim is to use green infrastructure to slow water and enhance ground absorption of water. By using, for example, green roofs, rain gardens, bioswales, parks and wetlands, the idea is to provide time for evaporation as well as transpiration. (A bioswale is a channel designed to concentrate and transport stormwater runoff while removing pollution and debris.) The overall idea is to design cities in a way to combat and sustain changes in our climate.
One type of city design will not solve all the problems that cities are facing due to climate changes but sponge cities can help us to deal with some of the challenges.
Imagine a green park that you can play in during dry weather, but when it rains, the green park is transformed into wetlands.
Often we think of cities as places that change the movement and distribution of water. Cities also remove vegetation and have a negative impact on biodiversity. The impact on coastal cities like Seoul and Mumbai might be a major problem if we continue to warm our planet at the current rate. Melting glaciers and ice sheets will add volume to the oceans. The chances of flash flooding will increase since changes in climate will lead to more extreme precipitation events.
BUT – we can design cities in new and exciting ways that can contribute to saving local plant and animal species.
Traditional stormwater management relies on “gray infrastructure”—concrete pipes and dams built to move rain off the land as fast as possible. Sponge city thinking flips that approach, drawing instead on “green,” or natural, infrastructure like rain gardens and forests. Rather than treating stormwater as a problem to be flushed away, the idea is to capture it and put it to use later, during dry spells. Sponge City Matt Jenkins 2020
You can use a kitchen or bathroom sponge to demonstrate how water is soaked up in the sponge. Mosses function as sponges, and they can be used if you make a model of your sponge city. Mosses soak up rainfall and help to maintain moisture in the soil below.
Have some fun and design your own sponge city!
Frequently Asked Questions
What is biomimicry?
Biomimicry is the practice of looking to nature for solutions, then applying what we learn to design and problem-solving. Instead of inventing from scratch, it means studying how plants, animals, and ecosystems have already solved a challenge — like staying cool, collecting water, or absorbing carbon — and adapting that strategy for human use.
How does biomimicry help address climate change?
Nature has been adapting to extreme conditions for billions of years, so many organisms already hold working solutions to problems we now face at a larger scale — cooling buildings without electricity (termite mounds), collecting water in drought (the Namib beetle), protecting coastlines from storms (mangrove roots), and capturing carbon (corals, forests, kelp). Biomimicry means studying those solutions and applying the same principles to human design.
How can children get involved in biomimicry?
Children don’t need special training to think like a biomimicrist — just curiosity and a habit of asking “how does nature solve this?” Simple ways to start include a backyard scavenger hunt for nature’s patterns, a “design-an-animal” challenge for a changing climate, or building a small model (like a passive-cooling structure or a water collector) inspired by something they’ve observed outdoors.
Is biomimicry only for scientists and engineers?
No — biomimicry is as much a mindset as a profession. Anyone can practice it by observing nature closely and asking design questions. Professional biomimicry practitioners apply it in architecture, materials science, and engineering, but the same core skill — careful observation followed by “what if we built it that way?” — is exactly what this post’s classroom and family activities are designed to build in children.
Åsa Jomård
In 2015, Åsa completed a course in Biomimicry: A Sustainable Design Methodology at Minneapolis College of Art and Design. With over 10 years of experience exploring nature for inspiration and as a former member of Ben, Biomimicry Education Network, she brings both academic background and creative teaching experience to her work. Her materials seamlessly integrate stories, nature observations, and design challenges, making them perfect for inquiry-led learning in early primary contexts.
AI was used as a Thinking Partner.