Orson Scott Card, "Salvage"

Deaver wants to look for gold by sailing out to where the skyscrapers stick out of the water.

(from Wastelands: Stories of the Apocalypse)

This is a crazy strange story about survivors scraping a living together by salvaging scrap. People live freely, for the most part, though Deaver Teague is not terribly trusting of the Mormons and their government. His apparent atheism causes friends to distrust him, making him want to find a place where he belongs.
What Happened: A big war, I think, and some catastrophic flood that's left Salt Lake City submerged. Gas, metal and other supplies are limited. There does appear to be some stability in the social and municipal infrastructure.
Destruct-O-Meter Score: 3? Maybe? Could be much worse than that, but the reader is rarely given a glimpse outside what this one little outpost. Perhaps it's only America that's been bombed backward.
Orson Scott Card's home page.