Most people don't realize just how much water they can collect from a single inch of rain. It's simple to figure out when you have the right formula....

Take your under-roof square footage. Don't forget to allow for porches, overhangs, carports, garages, barns, pole barns, etc.

Now multiply the square footage just found by .60.

Square feet x .6 = Total amount of water per 1 inch of rain

Take your average rainfall for the area and multiply it by the sum of the above number

This number will reflect the amount of water you could collect in an average rainfall year in your area

Example using an average of 32 inches of rainfall per year:

2,000 square feet x .6 = 1,200 gallons per 1 inch of rain

1,200 x 32 = 38,400 gallons of rainwater per year

This sample dwelling could collect approximately 38,400 gallons of rainwater per year

Do the math with your own measurements to see how it can work for you