Probably a very dumb question but here goes … why do the people have to move, can dykes/floodbanks/levees not be built?
Storm surge is like a slow tsunami, driven by weather instead of techtonics. And the Mississippi clears nearly the entire Midwest. Flooding anywhere along the tributaries ends up in Louisiana eventually.
That family is probably on the lower end of the buyout cost, but it puts the total cost of a buyout in the range of $1 billion or $10 billion.
So then the question is how much flood protection can be built for a similar cost.
I think there's also issues with flood controls for one area making flood control in other areas more difficult. So drawing a line can help with that.
Articles should show the maps.
Polders and Dikes of The Netherlands for comparison: https://www.thoughtco.com/polders-and-dikes-of-the-netherlan...
Of course they are allowing commercial developments to continue, check this out:
Louisiana – Other Oil & Gas Infrastructure: http://www.dnr.louisiana.gov/assets/images/oilgas/refineries...
Louisiana – pipelines and platforms: http://www.dnr.louisiana.gov/assets/images/oilgas/refineries...
And as far as protecting land value, that shouldn't be funded at a national level (it could be somewhat subsidized by cheap loans or something), it should be funded by the owners of the land.
I had never heard of salt dome storage until reading this book. Scary stuff.