Did you know that one-inch of rain will yield 550 gallons of rainwater, per 1000 square feet of roof surface? Our 16-inch average rainfall here in Far West Texas could yield 14,000 gallons of collected rainwater from an average-sized roof. If you're using rainwater in your home, you'll want a system that falls on your roof and carries the water to a storage container that will keep the water clean and prevent evaporation. This Nature Notes has nswers to all your questions regarding making rainwater safe to store for all uses in the home.