http://youcancompost.com/Rain-Barrels You can save money and take advantage of the nutrients contained in natural, Mother Nature-provided rain water by rainwater harvesting from your rooftop. Rain barrels are popular and can save approximately 1,300 gallons of water during peak summer months. You also keep that water from running off into sewers where most of it ends up leeching into lakes, rivers, and streams, contaminating fragile eco-cultures because of the chemicals it picks up along the way. Rain barrels can be used solo or can be grouped and connected for maximum collection.