I've recently found information, that the land to put the main city on, especially the 50 acre Hub, can't really place there normally. Because it is unsuitable at the moment, because of its high water table content. 

But here's the solution. Check out how the builders, for the Burj Al Arab Hotel in Dubai, solved this problem of building this structure over the Persian Gulf.
(VIDEO) https://youtu.be/yl0DpG8uiNc?t=977