Rain barrels are another way to protect your home from flooding by collecting and storing run off from your roof. Each 100 square feet of roof will collect 62 gallons of water during a 1” inch rain fall. Rain barrels, which are placed at the bottom of downspouts, collect the water which then can be used later. Rain barrels are an eco-friendly way to water your flowers and lawn when it’s dry out. They also decrease pollution runoff into lakes and natural waterways. Cornell Cooperative Extension has a guide to help you create your own rain barrel at http://cceonondaga.org/resources/how-to-build-a-rain-barrel
Original source can be found here.