Wanted to put this here because the Sonoran Desert isn't Ohio or Pennsylvania. We can't count on a rainstorm next week to fill up a cistern.

I'm here in central Phoenix, obviously on municipal water. Two adults, the dog, and caring for an elderly relative who lives with us.
Right now, our water usage is about 3000 gallons a month. In a SHTF scenario,  we could of course cut back significantly {wouldn't need almost daily laundry or bathing). Trying to determine how much to store, also how and where.

Our third bedroom has become our overflow storage area. We have no garage, but there is a covered back porch at grade. We can stack cases of water here and there, but that seems like a stopgap measure, at best, and doesn't really address hygiene applications.
Looking at places like Tractor Supply, I see above ground poly tanks up to several thousand gallons, 5 and 6 gallon jugs, 250ish gallon tanks like landscapers have on their trailers, and everything in between. The house has the typical block perimeter walls out back. They extend nearly to the front of the house, affording us 2 side yards about 10x30, one of which is concreted.

Looking for suggestions.

Also, I do have a 12 volt water pump that could be plumbed into a tank.

If (when?) SHTF hard enough to worry about water in central Phoenix, you need a plan to get out of there.  If there's no water, there's almost certainly no electricity or food delivery and probably minimal law enforcement.  Within a few days, your 'hood will make Somalia look like a resort destination.

While your point is well taken, "just leave" is often easier said than done. I've seen I-10 get totally jammed up on holiday weekends. I've seen I-17 shut down for hours both ways due to a brush fire. I've lived in other metro areas where the roads are clogged because 60,000 people were leaving a football game.

Trying to be someplace else, when 5 million other people have the same idea, isn't happening, absent private aircraft. Then there's the issue of where to go. Places that might ordinarily be friendly and welcoming are likely to be much less so when their space, resources, and infrastructure are swamped.


I know I can't realistically store enough of anything for ten years.

You need a large water filter and a 40,000 gallon pool...or neighbors with a pool.

Move out in the sticks.

That's what we're doing.

Water bed bladders make for good storage.

There are many ways in and out of The Valley that don't involve freeways.
You can stash enough water for a few days, weeks, but unless the power is restored and the pumps running, you will run out, and will need to relocate, Mogadishu style.

2500 gallon poly cistern, inexpensive, right height for gutter feed. Pick up a decent water filter.

https://youtu.be/R5hcsz3X3W0

Some good info in this series of videos