With summer coming, now is a good time to think about increasing your water storage. One practical way if you are planning to bug in, is to get the 275-gallon water totes. They are a heavy-duty plastic container surrounded by a metal cage. They measure 48 inches by 39 inches and are 46 inches high. They come with a valve at the bottom that can be reconfigured to allow you attach a garden hose. This a very compact way to store a lot of water.
The containers are stackable, but will weight approximately 2300 pounds when filled. I have used them and like them. They are easy to fill through the top. They have many uses and can be used for rainwater collection. I even know of one person who is going to use one in an Aquaponics system.
I see used ones for sale in my area for about $120 each. There are food grade and cleaned out ready for use. Because they are white, I would recommend protecting them from sun light if you intend to store water for a long period, this will help prevent algae growth.
Prior to filling them, I always double check to be sure they are clean and then wash the opening with bleach, just to be sure nothing gets washed in. I then fill them with a hose that is approved for drinking water use. You can find them at recreational vehicle shops. Once the container is sealed with clean domestic water, the water should stay good almost indefinitely as long as the container is intact. If the water you are filling the container with is questionable, you can always add bleach. Use unscented household chlorine bleach with no additives. You should use about ¾ of a cup of bleach.
I have had no problems with using these for storing water that is already several years old. Someday I will hook a garden hose on an use them to water my garden and then refill them. But I am not in a rush.