A rain barrel is a system that collects rainwater from your roof that would otherwise be lost to runoff. Rainwater harvesting is not new. A larger version of a rain barrel, known as a cistern, has been used for centuries. Rain barrels come in a wide variety of materials, designs and colors. A common size rain barrel is 55 gallons.
Why use a rain barrel?
Reducing non-point source water pollution
Reducing erosion from storm surges into our streams
Reducing the amount of treated city water used for watering lawns and gardens.