Figure out how many gallons of rain fell on your barn

If you’ve ever wondered how many gallons of rain water fell on your roof or your property, here is some rain math I whipped up this morning to figure it out after a weekend of heavy rain:

( ______ square feet  X  144 square inches )  X   _____ inches of rain / 231 cubic inches per gallon  =  _______ gallons of rain!

Knowing how much rain you could collect from a barn or shed roof is important information to know, especially for a farm with irrigation needs. Just like the abundance of free solar energy, rain water is one of those amazing natural resources that literally hits us in the face while we barely even think about it.

Knowing what natural resources are freely available to you is the first step toward harnessing and managing those resources into more sustainable living. This rain math tells me what size cisterns and pumps I would need. It also shows me how much municipal water we can save and understanding our impact on the Stones River watershed.