Hopefully, you will be able to bug in for an extended period of time. Having bottled water stored away will help ease the burden when you are getting your footing in tough times. You should have a minimum of two weeks’ worth of bottled water stored away, but as much as a couple of months. Again, if the emergency is short-lived, this will be enough to get you through.
I had the blessing of knowing my grandparents who lived through the Depression. I was a prepper before it was a ‘thing’. I always had a pantry to rely on. When I actually ‘got into’ prepping, I went overboard, was a bit fanatical, and then I got burned out. Too many ‘doomsday’ articles and sites. I have since changed my approach to more of a ‘homesteader’ mindset. Homesteaders and preppers have a lot in common, and the ultimate goal is the same, to be more self sufficient.
This group stresses being able to stay alive for indefinite periods in life-threatening wilderness scenarios, including plane crashes, shipwrecks, and being lost in the woods. Concerns are: thirst, hunger, climate, terrain, health, stress, and fear. The rule of 3 is often emphasized as common practice for wilderness survival. The rule states that a human can survive: 3 minutes without air, 3 hours without shelter, 3 days without water, 3 weeks without food. 
It’s impossible to carry all the food you will need for a week unless you’re eating very high density proteins like nuts. Nuts and dried meat are two of the easiest off-the-cuff meals. Canned food has a lot of water that is wasted during the cooking process. Stay away from heavily flavored or salted nuts. The amount of salt present in the unsalted nut mixes is still sufficient enough to replace electrolytes.