One inch of rain collected off a one thousand sq. ft. roof generates six hundred gallons of water. How much rain can you catch? Here is an easy formula: Measure the square footage of the collection area (for example a roof that is 30 feet wide x 50 feet long = 1500 sq. ft.) Multiply the area by the amount of rain in inches. Then multiply that number by .623 (that is the amount of water in gallons one inch deep in one square foot of space) equals the amount in gallons of water that can be collected. For example: 1500 square feet of roof area x 15 inches of rain x 0.623 = 14,017 gallons of water. Darko Kapelina believes that harnessing and leveraging natural resources such as rain, sun and wind for example, can move us closer to clean, regenerative and sustainable energy independence.