Water is a big priority of mine. I do store quite a bit as the horses take about 10 gallon per day on an average. I’m on a well so I also have a gen set to pump it when the power is out. The generator works for me as I have a storage shed a good distance from the house and barn for fuel storage. Even with that fuel storage is a pia as it has to be treated and rotated out.

I have several of these that were used for juice and was able to wash them out, they make great water storage barrels if you have a place to store them where they can be dumped. I keep mine behind some privacy fencing next to my horse barn in a shaded spot. I paid about $10 each for them. Soda pop bottling companies also sell them for about $10.
https://www.containerandpackaging.com/item.asp?item=D004

For water purification I keep a unopened gallon of bleach at home and rotate it every few months. In my vehicle and kits I keep these rather than the iodine tabs.

http://www.katadyn.com/usen/katadyn-prod...-package-of-20/