"You never purchases water. You just rent it." How true!

In an immediate urban evacuation, your top priorities are water and cash. It is hard to have too much of either. Other categories mentioned are important as well, and highly desirable, but at a short distance from the incident, life goes on as normal (except in a major earthquake or widespread storm).

My preference in water containers is a stainless steel cup holding a liter canteen (usually the classic Nalgene, but there are various drink bottles which will fit as well). Plastic containers won't crack unless completely filled and you can make coffee/tea/etc to your heart's content in the cup. Now we need a small stove....sugar?....