Most of the food supply in cans can be kept at least one year if not two, same for water in bottle (one year), cereals for breakfast (one year) and so on..Look at the validity dates on these articles you will be surprised about how long you can keep it.
For water a good filter (Berkey for sedentary, lifestraw for moving) and some water treatment pills is ok, it allows you to use water from rain, river or lake. You can store tap water for at least 6 monthes after adding a pill of chlorine / silver inside and close the bottle carefully.