We upgraded our water tank and retooled our old one for rainwater harvesting. The shiny new tank is connected directly to the water company's pipes and can hold up to 23 gallons. In case of service interruption, it is good enough for 48 hours of household needs. For drinking & cooking, we've got various filtration systems.
In a tropical country such as ours, we are visited by about 18-22 typhoons per year. It also rains most of the darn time. With my new system, we'll never be thirsty!
About 3 of these storms would hit our city directly, and maybe just one or two of these would knock out electricity & water for 1-2 days.
Its only a minor nuisance. The time spent in the dark with family is a good opportunity to actually try your survival gear. Mosquito nets, monopoly, candles & lamps, food, extra water, and medicine will all be nice to have for that short period while the power company fixes things.
Now once in a while something as big as Katrina or a screwed up nuclear plant would happen. A royal mess such as this would certainly put a strain on your life span. The living dead rising up to eat us all? I'm talking about that too.
This is where preparedness comes in.
This is my old tank. It can hold 40 gallons of skyjuice.
The Strategy of Water Storage
Water is life. If you have a lot of it, you could stay barricaded at home for extended periods. WTSHTF, one of the worst things you could do is to bug out at a time of great panic. What most survivalists don't get is that bugging out can be extremely dangerous! If you've built a strong home defense, then perhaps it would be better to hunker down during the early phases of the crisis.
Rainwater harvesting will definitely reduce the amount of time spent outdoors. Let me repeat: doing anything outside the safety of your home is EXTREMELY DANGEROUS. Especially if thousands of walking dead are out there. With a good rainwater harvesting system, you have one less reason to go foraging.
If you need to drink your stuff, make sure you have a sure-fire means of purification. More on that later.
My home has a stone perimeter wall that is 6 feet high. I've got lots of food, ammo, medicine, and a box of monopoly, crayons & musical stuff for my daughter to play with while the world outside goes nuts. So there's got no immediate need to bug out because of the preparations we've made. If we must escape, my emergency map will do the trick.