Yes/no/maybe. It never hurts to stock up on drinking water, but... water is very heavy and takes up a lot of space. This limits the quantity that most people ca

Yes/no/maybe. It never hurts to stock up on drinking water, but... water is very heavy and takes up a lot of space. This limits the quantity that most people can realistically store. But what you can do, if you live in an area where any source of freshwater (lake, creek, stream, river, pond, etc.) is available within a reasonable distance (a day's hike?) is learn how to purify water and stock up on the supplies necessary to do so. There are different ways to purify water, but one of the easiest and most effective is still good old fashioned boiling. So if you have a decent vessel for boiling water in, and a means of starting a fire, and some supply of flammable materials, you can boil quite a bit of water. If you only live near a supply of salt water, or if you live near water sources that are especially dirty / polluted, distilling the water is a step beyond boiling. It's more complicated, slower, and requires more up front prep, but it's not completely outrageous to think of building / buying a distilling unit in advance of a possible failure of the public water system. The downside of this, of course, is that it requires you have a good supply of firewood or other burnable material, and a place to light a fire where you won't kill yourself with carbon monoxide poisoning. Chemical purification is another option... and in a pinch, you can get by with plain old (unscented) household bleach. And, of course, as others have mentioned, there are filtration options. If you go this route, it might not hurt to pre-filter your water (depending on what state it's in) with plain cotton cloth, a coffee filter, etc., to help preserve the life of your filter. The idea is the prefilter step removes the bigger particulates so the "real" filter never sees them.