Can you prepare for disaster on a budget?
Absolutely!
The typical emergency preparedness mindset is to simply buy whatever you need. However, I, as well as others, either can’t or won’t do that.
So here’s something easy and frugal that I do anytime I get some sort of bottle. I rinse it out, fill it with water, and stick it in the fridge.

Not only does this reuse the bottle, but it also helps fill up the fridge to keep it colder and use less electricity. Plus, if I need it, we have water stored.