• South Korea agreed to host a UN-backed prototype floating city on Thursday.
• The project designers envision a flood-proof city that produces its own food and water.
• They plan to build the prototype entirely in Busan, a major port city, in 2025.

Over two years ago, a group of builders, engineers and architects gathered around a table at the United Nations to discuss an ambitious concept: a floating city that could withstand natural disasters, including floods, tsunamis and category 5 hurricanes.

The idea wasn’t entirely new: designers and developers have fantasized for decades about building man-made islands and metropolises on water. Even Homer envisioned a mythical floating city around 13 centuries ago.

But these visions were notoriously difficult to push forward – often because local governments did not approve of the proposals, citing concerns about better use of land.

The UN-backed project cleared that hurdle on Thursday, when the city of Busan, South Korea, agreed to host a floating city in collaboration with the project’s designer, OCEANIX, and the United Nations Human Rights Program. human settlements (UN-Habitat). Like many coastal cities, Busan is threatened by rising sea levels.

“Bhutan happens to be the best place to deploy this prototype,” OCEANIX co-founder Itai Madamombe told Insider. “But it is something that we hope will be of use to all coastal cities around the world and to all coastal communities facing the challenge of rising sea levels.”

Flood-prone city could be completed by 2025

The floating city of OCEANIX is essentially a collection of hexagonal platforms perched on top of the water.

Hexagons are widely considered among the most efficient architectural forms: they allow builders to conserve both space and materials. Imagine the orderly interior of a beehive – essentially a network of nested hexagons.

The city’s docks would be reinforced with a limestone plaster two to three times harder than concrete, but still load-bearing. The material is created by exposing underwater minerals to an electric current. In the presence of this current, it becomes stronger over time and can repair itself, allowing it to withstand harsh weather conditions.

The goal is to develop a flood-proof city that rises with the sea and produces its own food, energy and fresh water. Cages under the platforms could be used to house scallops, kelp, or other forms of seafood. And aquaponics systems could use fish waste to fertilize plants.

But the design is not set in stone and OCEANIX has not yet determined the size of the city.

Madamombe said his team will work with local designers in South Korea to adapt the prototype to the local environment. OCEANIX will unveil the results of these efforts at a second United Nations roundtable in April, she said. From there, the team will start designing the platforms and getting construction approval.

The cost, subject to change based on final design and materials, is estimated at $ 200 million.

“In total, it will take a total of three years,” Madamombe said. “So we predict that by 2025 we will see this prototype in the water.”

Busan vulnerable to typhoon flooding

Busan, a city of 3.4 million people, is home to one of the busiest ports in the world. Local builders and engineers therefore have experience in waterfront construction, Madamombe said.

The development would ultimately serve as a model for future floating cities around the world.

Hurricanes and floods are becoming more frequent and intense as global temperatures continue to rise. A recent study by Climate Central, a nonprofit research group, found that in the worst-case scenario – 4 degrees of warming – at least 50 major cities would lose most of their populated areas in the 200 to 2 Next 000 years due to sea level rise.

Coastal cities like Busan are particularly vulnerable.

Although the water surrounding Busan is generally calm, the city has also been hit hard by typhoons over the past decade, including Typhoon Chaba, which inundated the city in 2016, and Typhoon Kong-rey, which affected resulted in 55,000 power outages in Busan in 2018..

Madamombe said UN-Habitat will collect data on Busan’s development results. His team hopes to apply these lessons to their next project: OCEANIX is in talks with at least 10 other governments about building more floating cities, Madamombe said.