Plastic Rain Barrels

Are Plastic Rain Barrels for “second use” and are they “impractical”? This was a comment that I found on a rain water forum recently.

Plastic Rain Barrels can be a great way of collecting and storing rainwater but are they the best way? Rainwater tanks can store much larger quantities of rainwater while rain barrels can fill quite quickly and then empty again nearly as fast.

The impression most serious rainwater harvesters have of rain barrels is they are not practical and they do only offer a second use. Well, I would have to agree that rain barrels do offer a “second use” but for me, it is what I would call an “important second use”. As far as rain barrels not being practical? Well, I would have to agree with this but only if you don’t know how to get the most out of your plastic rain barrel.

I’ve got two, 55 gallon rain barrels that collect rain water from about half the roof area of my garage. I use these two plastic rain barrels for second use as I’m collecting rain water in much larger rain water tanks from the remainder of my roof area. The reason why I’m using rain barrels to collect this rain water is because it is difficult for me to collect it in my larger rainwater tanks. The alternative to me not collecting this rain water in rain barrels is to just let it flow normally down the downspout and not collect it at all. This rain water for me equated to about 2000 gallons per year so for me to collect it and store it in rain barrels certainly is worth my while.

So, to address the question of plastic rain barrels not being practical, there are ways you can set your rain barrel up so you really can maximise the rain water it collects. My two rain barrels hold a combined volume of 110 gallons. To fill them from empty takes about 0.6 inch of rainfall, so in most climates this means that your rain barrels will fill quite quickly and then overflow. It’s what happens next that decides whether my rain barrels are practical or not.

I have four options now as to what I can do with the rainwater that is flowing from the overflow of my rain barrels.

The first option is to just divert the rain water from the overflow straight back into the downspout and not collect it at all. This to me would make my rain barrels impractical as they would fill quickly and then overflow. This would be even more apparent if I was just using one rain barrel. That would mean every time I was to get more that 0.3 inch of rainfall the excess would be wasted and if my rain barrel was already full or even half full I would waste even more rain water. Most of the 2000 litres of rainwater that is diverted into the plastic rain barrels would be lost to me forever. This is how the majority of rain barrels are actually setup. They don’t actually store the majority of the rainwater that they collect. This is why some rainwater harvesters consider rain barrels to be impractical.

So the question is what to do to make them practical.

Well the first option is to install more than just one rain barrel. Obviously the more plastic rain barrels you install the more rain water you can store. Unfortunately though, many installations can be limited to just one rain barrel. Cost might be one reason as rain barrels aren’t the cheapest items to purchase these days but it is possible to make you own inexpensive plastic rain barrels for half the price or even less. Another reason is that some downspouts only allow for the installation of just one rain barrel. This is mainly because of the type of downspout diverter used. There are some downspout diverters that do allow rain barrels to be placed some distance from the downspout in a more suitable position which allows for the instillation of multiple plastic rain barrels.

The next option is to set up the overflow so as to direct the excess rain water to your garden. As most gardeners know deep watering is much more effective than shallow watering. Therefore when you garden is receiving rainfall from the sky it’s also receiving the excess rain water from your rain barrel’s overflow at the same time. The important consideration here is that from time to time you may receive excessive rainfall, therefore it’s best to set up your overflow so you can redirect rain water back into the downspout if required.

Another point to consider when directing rain water to your garden is to ensure that you direct it to an area where it will soak into the ground and not just run off on a slope and become someone else’s problem.

A third option that may be available to you, if your rain barrels are a part of a larger rain water collection system, is to install a pump to the outlet of you plastic rain barrels and then transfer the excess water to your larger rain water tank.

So, plastic rain barrels can be very practical. It comes down to how you go about setting them up.

You can make your own plastic rain barrels and install several of them in series,

Direct the excess rain water from the overflow directly to your garden

Or you can transfer the excess rain water from your plastic rain barrels to larger rain water tanks.