In my emergency backpack for water is 2 canteens that hold 2-quarts each, one is a collapsible military canteen with M1 cap and the other is a simple one bought at Wal-Mart but I find that it works pretty good, at least better than I expected. I have a metal water bottle/container and it is pretty thin to put anywhere in my pack. I have water purification tablets that can treat up to 5 gallons. I also have Ziplock freezer bags because they are made with thicker plastic than regular ones so they are good for storing, carrying water from a stream or some natural water source to another spot like the 'camp' area so to say. I am going to get a 10 dollar water pouch/bladder at Wal-Mart for 10 bucks or the 20 dollar backpack one, i'm more for 10 dollar one which I believe was another 2-quart. These are my water supplies so far. .^. I have the grey one I might also have a few water bottle on me at the time and would fill them all up if possible when I can. Plus I would share with people in my group who do not have water, and will help them find/get water.