What are the limitations or disadvantages of rain barrels?

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.

Chris Maxwell-Gaines: I am a professional civil engineer that focuses on creating impacting and sustainable projects by identifying all of the hidden water conservation opportunities available in a project. I am particularly interested in working within the realms of sustainable site planning, integrated water management and planning, and low impact development practices.

View Comments (4)

  • Hello
    I am working on a science fair experiment about overflooding. I wanted to ask if you knew why some areas still flood even after installing so many drainage systems and rain barrels and things like that.
    Thanks

    • It is all a capacity issue. Even with elaborate drainage systems, detention ponds, and rainwater harvesting systems in place, all those systems are sized for more "common" storm events. If our cities sized these systems for the largest storm events they ever experienced, those systems would cost a lot of money and their full capacity would only be used a very small percentage of time, essentially wasting all that investment. An analogy that I use is our highway systems... if we sized them to never have a traffic jam, we would have to spend a lot of money and then most of the day, the highways would be near empty, again wasting all that investment. Thanks for the question!

  • Good article. I like that you include using re purposed barrels.
    The best barrel is one with a hole in it.

    I put in a line of asparagus by my neighbors fence.
    I found a nice brown plastic barrel which looks like a whiskey barrel at the Goodwill Pound.
    To me the best barrel is one that has a tiny bleed hole in the bottom. I mounted up on the square water hose coil unit and put a square of board on top of that to lend stability.
    I discretely ran a small gauge water hose I found at the Pound behind the honeysuckle and and hooked it up to a 5/8 hose. On the top of this hose I drilled tiny holes and popped in those little black emitters 25c and the water bubbles out nicely on all emitters. This hose was an old one that I re-purposed. . I have an emitter that empties the hose of water.
    I covered the barrel with storm door grade mesh wire fashioned on a wooden square and placed a weighted shallow flower pot which has several holes in it on the top of the mesh and it's a tight seal to keep mosquitos out.
    I put two round pavers in the bottom of the barrel for stability.
    I drilled a tiny hole on the bottom near the edge and put a curved paper clip into that hole to slow the water leak out of the barrel.
    That water drops into a bucket or no bucket.
    I tilted the barrel a tiny bit for complete emptying.
    Having a sponge with a bit of infused Dawn placed in the flower pot might ward off mosquitos.
    The amount of water run off from the roof would fill the barrel in a good fall of rain.
    The set up does not look like an eye sore in the backyard.
    Asparagus would automatically get barrel water on top of the rain and I don't have to do anything.
    I can also disconnect the hose and let it run on somewhere else in the large raised bed that the asparagus grows in.
    We get about 18 ins of rain in Lubbock and every drop counts. Lubbock water keeps plants Alive, rainwater makes the Grow.
    Using re purposed items and elevating the barrel
    and secure seals is all it took and was less than $15 or less.

    • Morgan, thank you for your description of your rain barrel setup! Rainwater collection isn't rocket science and people can find many different ways to collect and distribute the rainwater. All it takes is a little bit of creativity. Now, there are a few best practices to follow in order to ensure that the rain barrel doesn't become a breeding ground for mosquitoes but other than that, you can do a lot of cool things with rainwater collection.

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