A little late to the game, here, but I don't see the big Culligan (or similar) water jugs mentioned. They are around 5 gallons (I think - 18.5 liters), pre-treated, and quite sturdy. You can get hand pumps that go into the bottles, or get a gravity-fed dispenser (no electricity necessary). I don't recommend storing them on their side - about 1 in 20 springs a leak at the mouth - but they don't have a huge footprint, and you can fit a few in the bottom of a closet. If you buy them before hurricane season, they will store fine through the season, and you can drink them and replace / refill them in the off season. We generally keep a few kicking around for power outages in the summer, as we are rural, and when the power goes out, our water pump doesn't work. We use rainwater for flushing and washing, to conserve the treated drinking water.
I have been thinking this over .... given that I am flooded now and will probably be in a draught by August. I already have a reserve tank for generaI use. I am thinking of setting up a reserve tank to water the garden as well as a third tank for a reserve for livestock.
"Good decisions come from experience. Experience comes from bad decisions." ... Mark Twain
We store 3 gallons of drinking water in glass per person and a few gallons of other water, in plastic bottles for flushing the toilet, washing dishes, etc. I make a point of using the water once a year, then washing the containers and changing the date. The glass jars are dated with a china pencil, the plastic with small labels.
Wow! A year later, this thread is still relevant. We are in what they are calling a 100-year drought. Water is being rationed (street water cut off for 2.5 days, back for 2.5 days. remembering whether we have water, and whether I can wash clothes, is a challenge, lol).
We had a party this weekend, at the tail end of the cutoff period, and the 500-liter tank in my attic ran dry just as we were washing up when everyone had left. I was very, very, very glad to have the 100+L outside on my porch for toilet flushing until the water came back a few hours later. We are just coming off of a week of rain, and we sit on top of a huge aquifer, but wells are running dry and the reservoirs are still empty, and rationing is expected to continue through the end of the year. As mentioned early in this thread, it is dangerous to consider yourself disaster-proof!