Many people spend hundreds of dollars each summer watering their lawns. However, had they installed a simple rain barrel they could have saved both money and water. One half-inch of rain on a 1,000-square-foot roof yields approximately 300 gallons of water. More specifically, 300 gallons of FREE water!
Rain barrels are an excellent way to conserve resources and reduce the amount of well or municipal water you use. Rain barrels not only conserve water but also filter out some of the chemicals that you find in tap water, such as chlorine and fluoride. In addition, rain water has no calcium or lime buildups, less sediment and dissolved salts, and it's softer and naturally warmer than tap water. All of these reasons help make stored rainwater a perfect choice for watering your garden.
You can buy a fairly inexpensive rain barrel at most home improvement stores. But, I ran across this fabulous video which demonstrates how to make your own rain barrel super cheap.