By the middle of the century, by one estimate, 800 million people will live in cities where the sea level could rise by more than half a meter. Many coastal neighborhoods already regularly flood. In South Korea, the city of Busan is planning a radical response: a new neighborhood that floats. As the sea level rises, so will the neighborhood.
It’s the first project for Oceanix, a New York City-based startup that has partnered with the city on the development, along with multiple other partners, including UN-Habitat, a United Nations program focused on sustainable development. Oceanix cofounders Itai Madamombe and Marc Collins Chen “were both concerned about sea level rise and its impact on coastal cities,” says Madamombe. “And we were also concerned about the land shortages in coastal cities and how they drive the price of housing up.”
They also saw the problems that happen when cities expand onto “reclaimed” land in the water. “You basically obliterate everything that’s in the ocean by dumping debris,” she says. “You’re also now more susceptible to sea level rise because you’ve destroyed your protective barrier, like mangroves.” Instead of destroying nature, the startup wanted to find a way to build that could help regenerate the marine ecosystem.
The company plans to build new housing and other buildings on large, buoyant concrete platforms that are anchored to the seabed—so they don’t float away—but can rise and fall with the water. (Because of the design and the local wave pattern, people on the platforms won’t feel the movement.) The concrete is designed to allow the growth of marine flora and fauna on the surface. The startup is also using a material called Biorock, which pulls minerals from the water to naturally build limestone. The Biorock can be planted with seaweed and other plants that can both help clean the coastal water and provide habitat.
The neighborhood in Busan will be connected to the local power grid but should be self-reliant, generating solar and wind power on the site that will be stored in batteries. The site will also collect and purify rainwater for use in the buildings and will process water used for showering or washing hands so that it can be reused. Residents will be able to commute to other parts of the city via a nearby subway station on land, though the site will also include office space, so some people will have the option to walk to work.
The project partners unveiled the design this week and will now have to go through the permitting process; after getting permits, they expect construction to take four to five years. Oceanix envisions similar developments in coastal cities around the world. “Our hope is that it can be in two kinds of cities: one, cities that are dealing with sea level rise; and two, cities that have land shortages and usually resort to land reclamation,” Madamombe says. “That’s very damaging to the ocean. We have figured out a way where we can live in harmony with nature—and not just actually live in harmony but actually regenerate it.”