If your interested in the value of gold in a destroyed economy, you can find some real-world examples of it.
Using Katrina as a basis for not having gold is incredibly stupid. There was no barter economy when it hit...There was only a survival economy.
For a real answer, look to Zimbabwe and their quantitative easing. When unemployment hit 90%, and bread costed trillions to buy, what did people use?
Gold.
The poor sifted night & day for it in the rivers to find some, and used gold dust as a basis for monetary transactions, since the currency was useless.
Gold has a use if there is an economy at all. For example, if the USA collapsed, foreigners would most likely offer to trade goods for gold, as gold would still have a monetary value outside of America. That is why it would have an intrinsic value.
Could gold be useless in any scenario? Of course. If zombies attack, or nazi space-aliens. But last I checked, these scenarios were far less likely as opposed to inflation/deflation which can still use gold as a means of trade both inside, and outside, of America.
*edit*
Here is the YouTube entry for 'Zinbabwe Gold For Bread Program':
http://www.guardian.co.uk/world/video/2009/feb/11/zimbabwe-gold-panning-starvation-food