Example of the math showing how the average home in the United States has over 33,000 gallons per year land on its roof. (Image courtesy Lonny Grafman)

Example of the math showing how the average home in the United States has over 33,000 gallons per year land on its roof. (Image courtesy Lonny Grafman)

Example of the math showing how the average home in the United States has over 33,000 gallons per year land on its roof. (Image courtesy Lonny Grafman)