First, let’s explore some of the semantics of rainwater harvesting. Rain barrel, as defined by rainwater harvesting professionals, are rainwater storage containers in the 50 to 250 gallon range. Typically, a rain barrel is a 55 gallon barrel. In many cases, that has been repurposed from a prior use.
A rainwater tank or cistern is a rainwater storage container that is anything larger than a rain barrel. It can be defined as a container that requires multiple people to install or construct in place. These rainwater tanks typically are installed to create a rainwater harvesting “system” since there are many other components that should be installed in order to create the most efficient and effective rainwater collection system.
Rain barrels are commercially available from home improvement stores, hardware stores, and garden centers. They can also be constructed from existing containers such as plastic garbage cans, recycled plastic barrels and whiskey barrels, and other containers.
If you are constructing a rain barrel from a recycled barrel, you do want to make sure it is a food-grade barrel and that it wasn’t a container that contained oil or a pesticide.
Also, you want the rain barrel to be dark-colored or opaque. Light-colored or translucent barrels allow sunlight in the barrel which promotes algae growth. If a light-colored or translucent barrel is all you have, then make sure to paint it a dark color.
Let’s start off with the benefits of harvesting rainwater with a rain barrel.
- They are a great introduction to rainwater harvesting and they can bring awareness to the need for stormwater management and to the opportunity for water conservation.
- Most likely these barrels had a prior life and are being reused to capture rainwater. This is great since it is diverting waste from our landfills.
- They are light and fairly easy for one person to move around and set into place.
- They can be deployed quickly but simply cutting back your downspout and installing the rain barrel underneath it.
Sounds great but what are their disadvantages?
- The main disadvantage is their small size which really limits the potential rainwater collection volume.
- To increase the rainwater collection capability, you would need to link multiple rain barrels together which increases the connection points and the opportunity for failure or leaks.
- Constructing a rain barrel can be a laborious endeavor when viewed in terms of its collection efficiency.
- Mosquito and other insect growth can be a problem especially for homemade rain barrels where attaching screens and such may be difficult to install properly.
The moral of the story…
Install as large of a rain barrel or rainwater tank that is feasibly possible for the location you want to place the rainwater storage container. As we have seen from the collection efficiency numbers in this post, it is always better in the long run to install a large rainwater tank in order to take advantage of the irregularity of rainfall events, both in their size and frequency (or infrequency).
Need some inspiration for the potential of rainwater collection? Check out some examples of containers larger than rain barrels in our rainwater tanks and cisterns portfolio page.