You need a lot more water; hand sanitizer is always a good idea. Also a good idea is a book on medicine, like techniques to make splints, take care of wounds, gashes, etc. I also keep on my backpack a small laminated book of different types of knots and how to tie them. Oh, and get a shotgun.
Water wise its just to get back home to where I have more, the home bag has some in it just in case I need to take it in a hurry somewhere as well.