In anticipation of water shortages in the future, we are considering purchasing a large above-ground tank or vault to use as a cistern, catching the rainwater off our large barn. Have any of you done this, and if so what type of storage are you using? Where did you get the storage tank? Do you use the water only for irrigation or could it be used for drinking too? The aquifer in our area is being rapidly depleted and rivers and streams are polluted with e-coli. In all probability, there will be problems with water supply in the not too distant future. Thanks for any pointers!