In recent years, as many cities work toward solutions for problems caused by stormwater runoff, urban dwellers have been encouraged to install rain gardens and rain barrels. Probably most people in these modern times do not realize that rain barrels are nothing new—people worldwide have used the concept of rain barrels for thousands of years. Cistern is the ancient name and the one familiar to most in this country who have relied on them as a convenient way to collect and store rainwater for essential household use. Now with urbanization and its accompanying stormwater problems, another very useful function for rain barrels has been identified.

With ever expanding areas of impervious surface— streets, highways, parking lots, buildings—stormwater cannot infiltrate to recharge aquifers as it did in the past. Instead, it rushes across these surfaces to nearby streams carrying all the contaminants and debris it picks up along the way. This increases the volume, velocity and pollution of stormwater reaching the stream and contributes to more damaging floods, erosion and deterioration of aquatic habitat.

Rain barrels/cisterns can make significant contributions to fixing stormwater- caused problems; are very adaptable for a variety of situations; and can be implemented by homeowners, businesses and developers. In many Low Impact Developments runoff is directed to huge underground or under street cisterns and the stored water is made available for landscape watering by the residents, thus keeping rainwater where it falls.

A surprising amount of rainwater can be harvested from just one rooftop. For example, the runoff of a 1.5-inch rain from a 750 square foot roof area is enough to fill nearly nine 50-gallon rain barrels.