Floating cities, a solution to rising seas?

At the Mipim World Real Estate Fair, which began on Tuesday and will end on Friday in Cannes (Alpes-Maritimes), a prototype of a floating city in the Maldives is competing to win a prize for the best large project.

This city does not yet have a name but will consist, assure its designers, of an assembly of floating platforms in the middle of a lagoon of this archipelago in the Indian Ocean. Some 5.000 colorful houses should stand there.

"A floating city is not a luxury, it's a necessity" for this island country whose very existence is threatened by global warming and rising sea levels, Paul van de Camp, head of the Dutch company Dutch Docklands, promoter of the project.

And the capital, Malé, where more than 150.000 inhabitants throng an atoll of 8 km2 entirely urbanized, is completely saturated, he recalls.

He does not dwell on the precise technical characteristics of the project, which will be officially presented in the spring by the President of the Maldives. Nor on their cost. But he promises that the financing will be assured and assures that the technical constraints are not prohibitive.

“There are very big global players who have helped us with systems for energy, sewers, water, electricity, which have been well tested and are relatively innovative,” assures Paul van de Camp.

He hopes that the site will be completed by 2027 at the latest and claims to have been approached to replicate the experience by "several countries", without specifying which ones.

Too expensive ?

There are already floating buildings around the world, just as traditional fishing villages are built on water, in the Amazon, Thailand or Indonesia, underlines Paul van de Camp.

But no modern project of this magnitude has yet seen the light of day.

Another is being prepared in Busan (South Korea), piloted by the company Oceanix and supported by UN-Habitat.

Here too, the technical details, the cost, etc. have not yet been disclosed. They will be officially in April, explains to AFP Itai Madamombe, founder of Oceanix. The objective is to have the project completed by the end of 2025.

Doubts remain, however, about the viability of such constructions.

For Ayça Kirimtat, a researcher at the Czech University of Hradec Kralove who has studied floating cities for a long time, the economic obstacle is difficult to overcome. "Building very large floating structures above sea level is much more expensive than normal buildings on land," she told AFP.

Energy, transport, services, food... the number of parameters to take into account is enormous, she underlines.

"I don't think there is a technology problem," thinks Nicholas Makris, professor specializing in oceans at the Massachusetts Institute of Technology (MIT). "It's more about economic efficiency. Managing to do everything in a feasible and economically viable way," he says.

Something possible in a place sufficiently protected from extreme climatic events and the hostile conditions of the high seas.

Emergence

What could ultimately make floating cities attractive is the rising waters, which threaten island states but also all coastal cities, thinks Chien Ming Wang, professor of civil engineering at the University of Queensland (Australia).

"For coastal cities, if you experience the waves and rising oceans, you have no choice but to bear the damage and rebuild. So it's very expensive", explains this specialist in floating cities, who was consulted for the Maldives project.

"With floating cities and homes, you don't have to worry about flooding since your home is always above sea level."

“We will see floating cities emerge all over the world in the next ten or twenty years,” he predicts.