How Do Rain Barrels Work?


Rain barrels have become super popular with gardeners over the past few years, and are a great way to capture rainwater to water your plants and gardens. But they don’t come with a pump, so how do rain barrels work? This is a very common question. In this post, I will clear up any confusion, and show you exactly how rain barrels work.

Last week a reader asked me “How does a rain barrel work?”. That is an excellent question, and one I often wondered before I bought my first rain barrel. I figure other people would wonder the same thing, so I decided to answer the question in a blog post.

But first, let’s talk about the purpose of a rain barrel.

What Do Rain Barrels Do?

A rain barrel is used for rainwater harvesting, and is a container that captures and stores rainwater. Rain barrels (aka: rain collection barrels) have been around for a long time, but they have become very trendy over the past few years.

Some people only have one or two rain barrels set up for rain harvesting, while others have an entire rainwater harvesting system installed so they can collect thousands of gallons of water.

There are lots of benefits to having a rain barrel, and rainwater can be used for many things. I use it mainly for watering my houseplants and outdoor potted plants, and for keeping my garden ponds and water features full during the summer.

Rainwater is also great for watering the garden and filling up wash buckets to use for odd jobs like washing windows or washing the car.

Rain barrels are used for rainwater harvesting

How Do Rain Barrels Work?

Rain barrels are designed for catching rainwater as it flows through or from the gutters of a house, garage, shed or other structure. Once hooked up, the water from the gutter is directed into the barrel.

A rain barrel can be hooked up to a gutter by installing a rain barrel gutter attachment, using a rainwater gutter diverter kit, or simply by attaching a piece of flexible downspout tubing.

The exact installation will depend on the type of rain barrel you have. Here’s how I install my rain barrel.

But basically, rain barrels have an opening on the top or side of the barrel to allow the water to run in from the downspout or the tubing from the gutter diverter.

Each time it rains, the rain barrel will be filled with rainwater from the downspout. Then the water will sit in the barrel until it’s ready to be used.

Flexible tubing diverts rainwater into the rain barrel

What Happens When A Rain Barrel Is Full?

It’s amazing how fast a rain barrel will fill up with very little rainfall, and all of that water needs somewhere to go once the rain barrel is full. And another really common question I get is “do rain barrels overflow?”.

Well, if you’re using a specially designed rain barrel gutter diverter kit, then the diverter is designed to stop the flow of water into the barrel once it’s full.

When the rain barrel is full, the diverter shuts off, and the rainwater will simply flow through the gutter like it normally would.

But, if your setup is like mine, and your gutter has simply been diverted to flow into the barrel, then it’s a bit different. Most rain barrels have an overflow valve near the top where the excess rainwater will drain out when the barrel is full.

I have an old cut off piece of hose that I hooked up to the overflow valve on my rain barrel so I can control where the water goes when it overflows through the valve.

But when there is a heavy rainfall, many times the rain barrel overflow valve can’t keep up, and excess water can bubble over the top of the barrel rather than out the release valve.

That’s not an issue for my barrels, because one is installed next to the garage and the other is next the side of our deck. But, if you plan to install a rain barrel next to the foundation of your house, and you have a basement, then I would definitely recommend using a rain barrel gutter attachment or installing a rainwater gutter diverter kit to avoid any risk of flooding.

My rain barrel overflow valve

How To Use A Rain Barrel

Now you might be wondering “how do I use a rain barrel?”. To use your rain barrel, you simply turn on the spigot at the bottom of the barrel. Rain barrels don’t come with a pump, so water pressure will occur naturally.

I use concrete blocks to elevate my rain barrels, which not only makes it easier to fill watering cans, but also allows gravity to help with water pressure so the water comes out faster. If you don’t like the look of the cinder blocks, you could buy a rain barrel stand for a much cleaner look.

Just keep in mind that the water from the barrel won’t flow uphill. I have a hose attached to my rain barrel spigot, but I can only use it if I keep it below the level of the spigot (or sometimes slightly higher than that if the barrel is really full).

Also, the farther away you run the hose from your rain barrel, the slower the water pressure will be. The weight of the water also helps with water pressure, so the more water that’s in the barrel, the faster the water will come out of the barrel. These are all important things to think about when you’re deciding where to install a rain barrel.

Water flowing out of the spigot on my rain barrel

Where To Buy Rain Barrels

They’re so popular, you can get rain barrels just about anywhere these days. You can find rain barrels for sale at home improvement stores and garden centers, or buy them online.

Many people have also made their own rain barrel out of anything from a small whiskey barrel to large food grade containers. So if you’re handy, that’s another great option.

I hope this post has answered the question “how do rain barrels work” for you. Now that you understand how rain barrels work, you can take the plunge and install your own rain harvesting system – whether it be a single rain barrel, connecting rain barrels together, or building a large rainwater collection system.

Products I Recommend

More Posts About Watering Your Garden

  • How To Water A Vegetable Garden (The Right Way!)
  • How To Install A DIY Drip Irrigation System For Potted Plants
  • Plant Watering Devices For Your Garden
  • 5 Tips for Watering Your Vegetable Garden

Share your tips on how rain barrels work for you in the comments section below.


Please enter your comment!
Please enter your name here