Gone are the days when you need to be carrying/storing gallons of fresh water for when TSHTF, you can now purchase cans of dehydrated water which take up a fraction of the storage space needed for the equivalent volume of water.
I recommend this to everyone, its a top quality product:
http://www.mredepot.com/servlet/the-1099...ted/Detail
Alternatively, if you feel skilful enough, use the following instructable to build up your own supplies of dehydrated water, but becareful, its easy to ruin it:
http://www.instructables.com/id/Make-You...ted-Water/
Happy prepping