The Engineering Behind the World's Tallest Indoor Waterfall

Reporter: Welcome, Dr. Sharma! Today, we are standing inside Jewel Changi Airport in Singapore, looking at the incredible HSBC Rain Vortex. At seven stories tall, it is the world’s tallest indoor waterfall. Can you tell us how this amazing structure was built?

Dr. Sharma: Hello! It is wonderful to be here. The Rain Vortex is a masterpiece of engineering. The building itself has a massive, dome-shaped roof made of glass and steel. Right in the center of this roof is a giant opening called an oculus. The oculus acts like a funnel. When it rains in Singapore—which happens very often—the rainwater lands on the roof and flows naturally toward this central opening, pouring down into the building to create the waterfall.

Reporter: That sounds beautiful, but what happens when it doesn't rain? Does the waterfall just stop?

Dr. Sharma: Not at all! Singapore has a tropical climate with plenty of rain, but we cannot rely on the weather alone. Inside the building, we have a complex water recycling system. We collect and store the rainwater in a giant tank hidden underground. When it is dry outside, we use powerful pumps to push this stored water back up to the top of the dome. This means the waterfall can run continuously, even on sunny days.

Reporter: As an environmental engineer, you focus on sustainability. How does this system help the planet?

Dr. Sharma: Sustainability is all about using our natural resources wisely. We do not use fresh, clean drinking water for the waterfall. Instead, we recycle the same rainwater over and over. Before the water is pumped back up, it goes through a filtration system. This system cleans the water by removing any dirt or leaves. Some of this recycled water is also diverted to irrigate, or water, the thousands of indoor trees and plants surrounding the waterfall. It is a closed-loop system, meaning almost no water is wasted.

Reporter: When you stand near the bottom, you feel a cool breeze, but you don't get soaked. How did engineers prevent the water from splashing everywhere?

Dr. Sharma: That was one of our biggest challenges! A waterfall this high creates a lot of wind and turbulence as the water falls. To control the splash, the water flows through a lightweight, transparent acrylic funnel at the very bottom. This funnel guides the water smoothly into the underground basin. We also designed the shape of the waterfall to be aerodynamic. This means the air and water flow together in a controlled spiral, preventing wild splashes and keeping visitors dry while they enjoy the view.

Reporter: It is amazing how nature, art, and engineering come together here. Thank you for sharing these secrets with us!

Dr. Sharma: You are very welcome! I hope this inspires young minds to think about how we can design cities that work in harmony with nature.