User blog comment:JERealize/What lies beyond Panem?/@comment-83.160.118.170-20120904130915

It's easy to assume Europe has flooded and entire continents were erased, but seeing this takes place in the far future and taking into account the state of technology when it comes to watermanagement I think it probable that for instance the coast of Europe was preserved or won back from the sea. After all, about half the Netherlands was 'made' this way. (starting hundreds of years ago. Also, they actually built Palm Deira, part of Dubai, in the Persian Gulf.

So not only floods, but also the level of technology (that seems very advanced in the books) is a factor.