Living on water will soon no longer be a utopia

The floating cities of the future will be self-sufficient, without a car, and anchored one kilometer from the current coastal cities. Fantasy? The project, supported by the UN, will soon see the light of day.

Walk on water ? No need to work miracles to achieve this. In 2049, the idea of ​​living on the sea is no longer a fantasy, even less a fate reserved for a few fishing villages. These new cities are high-tech, organized in hexagonal clusters of buildings of four to seven floors, each platform can accommodate about three hundred inhabitants. A group of six platforms constitutes a “village”, and six villages form an entire city, where some ten thousand people live on 75 hectares.

Utopia? Not at all. Last April, a round table was held on the subject at the headquarters of the United Nations (UN) in New York. Architects, economists, developers and building manufacturers have taken great strides and are committed to presenting a floating city prototype, called Oceanix City, in the short term, in partnership with the country that will host it. “Several countries are under discussion ,” said Marc Collins Chen, former Minister of Tourism for French Polynesia and CEO of the private company Oceanix. We have a list of five finalists. The selected project should be announced in 2020. “The first floating city of the future will undoubtedly see the light of day in a region close to the tropics, probably in Southeast Asia or Africa. If the experience is satisfactory, nothing will prevent the multiplication of these descendants, of a very new kind, from the ancient lake cities.

These cities may have automatic vehicles, but will ban cars. They will be self-sufficient in fresh water, energy (solar), food and waste treatment. The vegetable gardens will alternate with vertical farms and greenhouses. Under the platforms, cages will be used to harvest seafood and kelp. Pneumatic tubes will transport the waste to a unit where it will be sorted and recycled. As for fresh water, it will come from rain, desalination of sea water and systems condensing water present in the atmosphere.

Sheltered from hurricanes and tsunamis

The pedestrian streets will allow residents to easily go from one building or hexagon to another, or to go to the spiritual center, the cultural center and the municipal library to rent computers, books and bikes. “Floating” cities will not be literal: they will be anchored 1 or 2 kilometers from the coast, in bays or areas protected from violent swells. They will have been designed to withstand category 5 hurricanes (winds of more than 251 km / h) and will be protected, at this distance from the coast, from any risk of tsunami.

The drawings of Oceanix City, which we owe to the office of the famous Danish architect Bjarke Ingels – already at the origin of a floating student residence built from containers in Copenhagen – have a little air of too happy utopia to be true, as it should be for a futuristic project. At the UN meeting, some compared the experience to the trip to Mars. However, in reality, most technological problems have already been resolved or will be resolved in the short or medium term. And construction should be able to be done at a reasonable cost: minimal land prices, economies of scale linked to modular manufacturing, durable materials (wood, bamboo) but removable to evolve with cities … “I think that these homes will be clearly more affordable » as new construction in the coastal region, predicts Marc Collins Chen.

What may still seem very futuristic to ordinary people is no longer so for those who work in the field. The construction group Bouygues was present at the UN round table and actively ponders the concrete challenges posed by these floating cities. “We can bring a certain number of tangible results and research elements to this project”, says François Pitti, director of prospective and strategic marketing at Bouygues Construction. The French giant has expertise in many areas that will be crucial: modular construction, energy, waste management, water … He is not the only industrialist in the starting blocks. Last October, in Miami, the convention of the venerable American Society of Civil Engineering presented five types of “cities of the future” over a horizon of fifty years, where floating cities were in first place. Also in October, in Washington, Rear Admiral David Hahn, chief of naval research for the US Navy, participated in a “Floating Future Seminar” organized by the Embassy of the Netherlands, in which urban development on the water was discussed in detail.

The current trajectory leads straight to a dead end. 90% of the world’s population lives less than 100 kilometers from a coast, so it is in these regions that the titanic problem of the arrival of nearly 3 billion additional urban residents will be concentrated by 2049. By that date, more than two-thirds of the world’s population will live in cities. Between population growth and migration to large coastal cities, “it’s the equivalent of a New York that will have to be built every month for forty years,” insists Marc Collins Chen. This will require pouring millions of tonnes of concrete, “while we are already consuming sand twice as fast as the planet can renew it”.

Aggravating factor: construction in the coastal zone is increasingly threatened by the inexorable rise in water. Amina J. Mohammed, Deputy Secretary General of the United Nations, during the Oceanix presentation, noted during the presentation:

“In Bangkok, the ground on which part of the city is built sags by 2 centimeters per year according to some estimates, while the water level rises in the Gulf of Thailand. ”
In fact, most of the world’s major coastal cities are directly affected by global warming: nine-tenths are vulnerable to rising sea levels; of the twenty-two mega-cities with a population of more than 10 million, fifteen are coastal cities.

Many are still in denial of reality. Not David Burt. This consultant, who had anticipated the subprime crisis in 2007, this time set up a betting fund on a real estate crash caused – perhaps as early as 2020 – by global warming. Many dwellings located near the coasts are indeed priced far too high if one takes into account their vulnerability to disasters. Especially since insurers no longer want to cover this kind of risk: in Houston, 80% of the homes flooded by Hurricane Harvey in 2017 were uninsured. The government has compensated some owners, but the staggering cost of Harvey, estimated at 114 billion euros, shows the limits of the status quo.

Faced with this rising sea level, the first solution is of course the construction of dikes. But these are incredibly expensive to build and maintain. In Fukushima, a construction of 220 kilometers in length, carried out after the nuclear disaster of 2011, cost 11 billion euros. Most poor countries and the majority of cities, even those in wealthy regions, do not have this kind of means. Jakarta, in Indonesia, was thus to erect an armada of dikes but recently threw in the towel given the estimate (36 billion euros). Even the Netherlands, undisputed pioneers in the field, wonder how far they can delay the inexorable. Most recently, a geographer from the University of Utrecht suggested that learning German as a second language should be compulsory,

A second solution to rising waters is precisely to “move” cities inland. But then again, the costs will be staggering. Marc Collins Chen explains:

“Even if there is space, you have to connect people, build new highways, train and subway lines and stations, etc.” It’s much easier to do it on the sea: water is a natural highway, you don’t need a license, only boats. ”
And on a social and psychological level, who will accept the idea of ​​abandoning a Manhattan to move a few dozen kilometers inland? “There is social infrastructure, human networks,” says Collins. People will be tempted to say, “ Why not stay here? ” ” But under different conditions. The interest of preparing for these floating cities, of planning their construction, “is to avoid informal, anarchic configurations” , underlines François Pitti, of Bouygues. It will not be easy. The challenge of these new marine cities is not only technological; the invention of such integrated societies will pose multiple human challenges.”The complexity of the interaction between human and ecological systems is an extremely difficult problem” to solve, said the Nobel laureate in economics Joseph Stiglitz, also present at the UN round table. “The only way to see if it works is to build for real” these floating cities. In 2049, this will be done.