Male is the capital of the Maldives. Slightly over 100.000 people on a very restricted space in the middle of the Indian ocean. A substantial part of the city has been recently built, and land reclamation is still active, as the images from http://landsatlook.usgs.gov/ show. A race between urban and demographic growth on one side, and sea level rise on the other side due to climate change.

But this is not the Netherlands, or New Orleans. There is no hinterland to reach in case of flood. And anything thrown to the sea could be nearby, and brought back by the tide.