Small communities or nations can also do some things that don't necessarily scale at large. An example of this would be Singapore and a few others I am sure we can create a short list of. I imagine tourism, banking, bitcoin mining are all possible industries if infrastructure is planned properly. I haven't gotten to the comprehensive list of the cost of infrastructure on the island itself but from preliminary calculations and research I believe that the dredging would likely be more expensive than the infrastructure itself. However, my idea is that everything would be circular and self sufficient in nature. Basically, near zero waste and life essential items such as water and food are mostly created or grown on the island. This would require a lot of forethought in the zoning and city planning department but it is not outside the realms of possibilities given that we can learn from previous examples of island nations.
You see, this is the problem, you take only the good parts from everything and ignore the rest.
Singapore is a 6 million poeple nation which is in the middle of all trading routes and it imports 90% of its food and 97% of its energy.
You can't have a thing that is in the middle of nowhere become both a tourist attraction and a banking center, you can't have both tourism and self-sufficiency in food on a small island (both Maldive and Seychelles import tons of it) and you will not get mining going with solar panels.
Not even going to mention the other fact, and this is coming from the black sheep of a 4 generation farmer family you won't get crops from that thing, not with a ton of potassium-rich fertilizer. Of course, it can be done, but the bill is going to be insane.
Btw, what is the cost for dredging enough soil to make a 47 sq miles island, even if we assume what, 1-2 meters deep ocean at that place?
Fine lets use the Cayman Islands as an example then? Are they sufficiently small? You can definitely get mining going with solar panels, a tidal array, wind power, and even biogas would be on the table. You can have strict zoning district for farming, industrial, tourism/shopping, and an urban center. It all really depends on the city planning. I mean the dutch turned the flevopolder into arable farmland and this is nowhere on the scale of that. In all honesty, you would create a zero waste environment in which everything is composted and that does also include the sludge from wastewater treatment. That is the part in which when treated properly you get nutrient rich compost and also biogas to be used for power generation. It is basically a win/win scenario. Modern agricultural practices of using chemical fertilizers are pretty damaging and do nothing to maintain the fertility of the soil in which you are growing in. Also, if you are worried about the salinity of the soil, I have grown food in an almost identical climate and soil conditions as would be present there. I basically just amended the sand with 6-8 inches of compost while adding compost made from my yard, garden, kitchen, and animal waste. After awhile you end up with a very fertile layer of topsoil that is also very well draining. As far as the dredging, it is too early to really say how much material is going to be needed to be dredged. The entire area is about 46 square miles but you wont be able to use it all. Maybe only 29 or so is usable and the rest will be used for material to create the island. The first four phases which would maybe be around 18 square miles in total and would be the most shallow areas. Possibly, with the state of the art process using cofferdams and vibro compaction, you could do it for
maybe around a billion dollars. The price tag sounds pretty steep but its not really all that bad in regards to material moved nor price. There have actually been dredging projects that have moved more material than this one. You would likely need to presell lots among other things to get money flowing. Possibly this could be done by first doing a small proof of concept. At any rate, this is all preliminary as I have to wait for the survey to be conducted first before I can even really definitively say its possible on any level.
Your biggest problem it seems to me is that the upfront costs are going to be very large and very real, whereas your benefits seem rather vague and ill-defined.
How did you come to your estimate of a billion dollars? Its hard to find reasonable numbers for this sort of thing but the "World" the artificial islands that Dubai was (are?) building were meant to cover a total of 20 sq miles (rather less than your expected area) with a projected budget of $14billion. They of course were close to a developed country and were actually part of an already functioning country.
