Our county went through a couple years of drought and rationing, and I built my system large enough to store almost 500 gallons. Then last summer we bought a pond form, and started laying plans to connect a pump to the barrel system that would pump the overflow into a 115 gallon wetlands holding pond, where it could be released through drip irrigation to the blueberry patch and then downhill to the tomatoes, gourds, peppers, etc. (Plus a friend has offered their used pond form which appears to be another 100 gallons or so, and we'll try to hook it up as well).
Never mind that this appears to be one of the wettest winters we've had in ages. Put that thought right out of your mind.
The drought will return. It nothing else, I can store enough water to negate any outdoor water usage on my town water bill.
These are my water barrels (the Greeks as they are known,since they started life in Greece carrying olives), and the older trashbin system in the background. All in storage for the winter, and actually at the moment covered in deep snow (we got 16" this last weekend).
These four will replace the original "trashbin" system, and the trashbins will go out to Dad's farm so he can use them to store drying walnuts.
Recycle, Reuse.....repeat as necessary.