OH! I love SHTF threads!

For water, the best set up would be a well with wind and/or solar driven pump system.

The reasons are:

1.no new filters made, forever.
2 sustainability
3 crop irrigation
4 independence from municipal systems

Rain barrels & downspouts can be ghetto-filtered by overlapping screens and layers of lump charcoal & pea gravel It works even better if you build an underground cistern that the downspouts connect to.

If the government does truly fall, the utilities will be the first to go as soon as employees realize that they wont be getting paid anymore and what money they were paid in is useless.

If the SHTF really, the inner cities & close-in 'burbs are going to turn into warzones a la post-Katrina, mostly from people shooting each other over cans of creamed spinach down at the local Safeway.

We have 3 contingency plans for SHTF:
2 short term and 1 long term

Head to the in-law's farm.
Load up the camper and head for the hills

or

Help ourselves to a large sail boat down at the local marina and GTFO of dodge.