Remembering Kongjian Yu: Father of the Sponge City Movement

We are deeply saddened by the passing of Professor Kongjian Yu, one of the world’s most visionary landscape architects and a protagonist in Our Blue World. His untimely death is not only a personal loss to those who knew him but also a profound moment for the global water and design communities, where his ideas and influence have left an indelible mark.

A Revolutionary Vision

Kongjian Yu was best known as the father of the Sponge City Movement — a concept that has reshaped the way the world thinks about urban water management. His guiding philosophy was beautifully simple: “It’s important to make friends with water.” Rather than fighting against floods, rain, and rivers with concrete and steel, Yu urged cities to work with natural systems, absorbing, storing, and purifying water in ways that made communities both safer and greener.

This was not just design — it was a revolution in thinking. Yu invited us to imagine cities where floods were embraced instead of feared, where once-barren streets could bloom with trees and wetlands, and where ecological wisdom and human ingenuity could meet to create thriving, resilient spaces.

Yu’s journey to becoming one of the world’s most respected urban visionaries was filled with challenges. Once a lone voice pushing back against traditional grey infrastructure, he spent years travelling across China, tirelessly presenting his ideas to hundreds of mayors. His book, Letters to the Leaders, became both shield and sword — a direct appeal to decision-makers to reimagine their relationship with water.

For many years, his proposals were met with ridicule and rejection. Yet Yu persevered. His determination eventually found resonance in China’s Environment Minister, who saw the power of his ideas and supported the creation of the first Sponge City. This living experiment became a green oasis that could absorb rainwater, filter it, and store it for future use.

That one success sparked a wave. Today, more than 500 Sponge City projects flourish across 200 Chinese cities, inspiring countless planners, architects, and policymakers worldwide.

Yu’s influence extended far beyond China. His approach resonated with international audiences, policymakers, and communities searching for sustainable solutions to the twin crises of water and climate change. From the wetlands of Asia to urban centers in Europe and the Americas, his vision inspired a new way of thinking about resilience.

In Our Blue World, Yu’s story is told as part of a larger journey into humanity’s evolving relationship with water. His voice carried not only the authority of a scholar and practitioner but also the conviction of someone who had lived through water’s destructive and healing powers. In the film, his presence embodied hope — showing that even the most entrenched systems can change when perseverance meets imagination.

Professor Yu’s passing is a great loss, but his ideas will continue to ripple outward for decades to come. The sponge cities he inspired stand as living testaments to his creativity and courage, proving that cities can thrive when they respect and work with the natural world.

More than a designer or planner, Yu was a teacher, a storyteller, and a changemaker. He challenged us to see water not as an enemy to control, but as a friend to embrace. That shift in perspective is perhaps his greatest gift to the world.

As we mourn his loss, we also celebrate the legacy he leaves behind — one written into landscapes, communities, and minds across the globe. His vision continues to inspire all of us working toward a future where people and nature flourish together.

Our thoughts are with his family, friends, colleagues, and the many communities touched by his remarkable life’s work.