Just because the lights are out, the floodwaters are rising and the end may be near doesn't mean you might not need to go to the bathroom. When nature calls, and you've unfortunately run out of toilet paper, dial up that old dusty phone book.
Tear out a few pages; crumple them up and smooth them out a couple times to make them more pliable and wipe away. Just don't flush them, or you risk clogging the plumbing (and the plumber won't be making house calls just then). This makeshift TP might be a little harsh on the backside, but chances are you'll have bigger worries to contend with [source: MacWelch].