It sounds like science fiction, straight from Jules Verne—huge hexagonal platforms that are attached to the seabed and to other platforms in a circular pattern. Each platform would house a few hundred people and each city would have approximately 10,000 inhabitants. In the center would be shops, schools, cultural and sport centers, medical facilities and other essential community services.
Seventy Years of Planning
The idea of cities floating on water has been around for a long time. European cities like Venice and Amsterdam as well as many fishing villages in Southeast Asia and South America have had a culture of living on water for hundreds and, in some cases, thousands of years.
From the 1950s to the 1970s architects tried to design floating cities that would let their inhabitants live in comfort and travel with ease throughout the area. They believed that such cities would be perfect for places that are otherwise uninhabitable, such as Polar Regions and in the middle of oceans.
The Japanese had initial plans for two such cities and the American futurist architect, Buckminster Fuller, designed Triton City, which was to be connected to the mainland with a network of bridges. Though these plans spawned technology that was viable enough to be patented, the projects were too expensive to be practical.
There were even plans for small, independent floating countries that could be used not only as resorts, but as tax shelters for the rich. The country of Sealand, for example, was to be built off the coast of Britain but never made it past the initial planning stage.
The first UN Habitat Conference took place in 1976 with the goal of developing alternative human settlement policies and planning strategies for the future. This conference opened the door for new ideas and some limited funding. Development was still only in the lab and on paper, but progress was being made, slowly but surely. 
This past April the most recent UN Habitat Conference highlighted the idea of floating cities as its feature theme. With scientists forecasting that ocean levels will rise more than 50 centimeters by the end of the century, causing major flooding in and even annihilating many coastal cities—including the UN’s home base, New York City—they are rightfully saying that the time to act is now.
The UN has teamed up with MIT, the Explorers Club, and Danish architect Bjarke Ingels’ company Oceanix to create Oceanix City, the first man-made floating city. Oceanix takes its cue from the many floating environs already in existence around the world, from thousands of homes and several floating dairies in the Netherlands to floating manned gas and oil exploration stations and bases for marine biologists. 
Ingels states that the homes in floating cities will be priced for the middle class, not just the rich. Oceanix’s goal is that the cities will be sustainable, self-sufficient enterprises. For example, cages attached to the clusters will grow and catch fish and seafood for all of the city’s inhabitants. Each city would have its own waste-water recycling plant, a desalination plant, and electricity would be provided by natural sources such as wind and sun. 
Without a doubt the #1 obstacle is the huge cost of such a project. Mass production will be essential to make the costs manageable. Oceanix proposes that, in order to ensure optimal costs, everything¾including furniture for the homes¾should be provided by the developer of the cities.
There are also technology barriers to overcome. The people working on the project claim that they are technically ready and that all the planned facilities could withstand a Grade 5 storm as well as hurricanes and tsunamis. However, until the first city or mini-city city is built, there isn’t even a guarantee that they will float.
Politics, as always, is another potential obstacle. If these man-made cities are in international waters, it raises the tricky question of citizenship. For now, the UN is talking about cities built off the coast of existing major cities that would be part of these cities. One proposal, for example, is that the first city would be built near New York City as a new borough.
Another significant obstacle is the psychological challenge of living in a small closed society that is floating in the middle of a major body of water. Inhabitants will have to be properly prepared for what to expect when living in these conditions before embarking on their new lifestyle. 
The Final Note
The world is already feeling the effect of the seas rising due to climate change. Jakarta, the capital of Indonesia, had devastating monsoons last month, causing Indonesia’s president to declare that a new capital will be needed to replace the waterlogged city before it sinks completely like a modern-day Atlantis.
While the cost of floating cities is very expensive, the projected costs for building on high ground are even higher. Despite the obvious obstacles, floating cities do seem like a viable solution to a problem that will only be escalating in the near future.
 Brydon T Wang, Floating Cities, the future or a washed up idea, June 3, 2019
 Andrew Revkin Floating cities could ease the housing crunch says UN, April 5, 2019
 Daniel Oberhaus, Sea levels are rising, time to build floating cities?, April 5, 2019
 George Wright, Floating cities, fantasy or the future, April 7, 2019