One thing to consider when selecting foods to purchase is how much water is needed to cook them and what to do with that water after cooking. Pasta needs gallons of water while New England clam chowder neeeds none. Canned vegetables are canned in water - is it useable?
Water conservation and use will be the difference between life or death.
Drink it as is, throw it in the soup pot, flavor rice or beans with it.
Alternate pasta with other dishes that absorb water. Save the spaghetti water and use that when cooking your rice (instant mashed potatoes, oatmeal, grits, soup).
Also, I have a "30 day supply" of MREs, which consists of 90 MREs. At one per day shared among a family of four, that can add a lot of variety and nutrition to the other stored food for three months.
Yes, it's called vegetable stock. Whenever I have freezer room, I keep a 3 lb. margarine tub to drain canned veggies into. When it's full, it's the perfect size for a pot of soup. Waste not, want not. Certainly, don't throw it out in a SHTF situation.