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Do Rain Barrels Work? 25 Questions Answered!

We’ve just finished the guttering on our new outbuildings, and we’re now looking into buying some rain barrels for the downpipes – but are they worth fitting?

Rain barrels for home use come in a standard 50-gallon size, and are a very good way of harvesting rainwater in your yard. With a special adapter kit, you can divert rainwater from your gutters into the barrel, then direct it back down the drain when the barrel is full.

Let’s dive down into the subject of rain barrels in more detail, and answer all your most common questions about what they are and how to use them…

Click here to check out the latest prices on rain barrels at…

Do Rain Barrels Really Work?
Our rain barrel works….even if it is a little wonky!

Are Rain Barrels Effective?

If you live in a rainy climate and have a decent-size yard to keep watered, a rain barrel is a great idea. Provided you fix them up correctly, they effectively gather the rainwater from your gutters and store it, ready for use on your plants, lawn, and vegetables.

Using rainwater is good for your plants, as it’s pure and untreated. It’s also good for your utility bills, and if you enter a period of drought, you’ll still be able to care for your plants. You can even use the water for washing your car or cleaning down your patio – basically, any outdoor task that doesn’t require drinking water.

If you weren’t harvesting that water, this wonderful, natural resource would literally go down the drain. If you invest a bit of time and money into installing a rain barrel, it’ll definitely be worth your while. If you don’t have an outside faucet, a rain barrel is a must for your regular watering schedule.

What Happens When a Rain Barrel is Full?

If you’ve had a lot of rainfall, there’s a chance that your rain barrel will fill up before you’ve had the opportunity to empty it. What happens then? Does the barrel overflow and cause an extra flood of water in your yard?

A commercially bought rain barrel will usually come with a diverter kit. This means that if the rain barrel suddenly fills up, or reaches capacity before you can drain off some water, any further rainfall is diverted away from the barrel. The diverter shuts off, and the rainwater goes back to simply flowing down the gutter.

If your barrel doesn’t have a diverter, it may still have an overflow valve, which stops the barrel from overflowing in a dramatic fashion. However, we’d recommend a proper diverter, to avoid sudden floods (especially if your barrel is attached to your home’s gutters).

rain barrel

Why Would Rain Barrels Be Illegal?

In most US states, not only is harvesting rainwater completely legal, it’s actively encouraged. It takes the pressure of the mains water use, and is a great way to keep our homes looking lush and green. However, it is illegal to harvest rainwater in Colorado – why on earth is this the case?

Well, like many quirky laws, this is an old rule that goes back to the days of the gold rush. The theory behind this old law is that if you harvest rainwater, you may be preventing it from running downstream to your neighbor’s property. In other words, you are stealing someone else’s potential source of water.

However, there are caveats, and Colorado allows you to take up to a specific amount of rainwater per year. It isn’t illegal in Ohio and Utah, but it is restricted. Take a look at the state-by-state water harvesting rules on this list.

How Fast Will a 50 Gallon Rain Barrel Fill Up?

Many barrels are around the 50-gallon size: how quickly will this capacity barrel fill up? Well, this depends on where you live, the time of year, and whether you’re experiencing light, moderate, or heavy rainfall.

Let’s use moderate rainfall for our example. Around an eighth of an inch of rain may fall per hour during rain of this type. So, if you’re draining the water from a 500 square foot roof, your barrel will take around an hour to fill.

If you live somewhere that’s prone to rain, you’ll need a larger barrel, or multiple ones.

Do Rain Barrels Attract Mosquitoes? (Do Mosquitoes Breed in Rain Barrels?)

Unfortunately, yes. Mosquitos are plenty good at reproduction. They can lay eggs in kiddie pools, buckets, pools made in hollow stones, air conditioner drip trays, your kid’s toys, trash cans, birdbaths, gutters, dog water bowls, indents in your sidewalk, under your deck, potholes in your driveway, in water features, on tarps, in low spots on a poured slab patio, hollow tree stumps, or on a soggy area of your lawn.

In fact, a female mosquito needs only a bottle cap’s worth of water to lay her 100 or so eggs.

The easiest thing to do is cover the top of the barrel with a net. This will also prevent leaves and other debris from falling into the water and potentially causing blockages, so it’s a good idea in general. Make sure that the holes in the net are 16th of an inch or smaller.

You can also add a dash of eco-friendly dish soap to the top of the water. Mosquitoes hate this, as it forms a film on top of the water that prevents them from laying their eggs. Good general barrel hygiene can also prevent it from becoming a nursery for little critters. Scoop out debris, and give the whole barrel a good scrubbing at least twice a year.

Rainwater barrel

Do Rain Barrels Really Save Money?

Yes they do. It’s not possible to give an exact figure, as every household’s water usage is different.

However, it’s reckoned that outside water use (watering the garden, washing the windows, cleaning the car and so on) can account for up to 40% of a household’s total usage. That could add up to a significant saving. 

Click here to check out the latest prices on rain barrels at…

What Do You Do With Rain Barrels in The Winter?

How do you winterize your rain barrel? If you get frost and ice where you live, you’ll need to stop using your rain barrel during the freezing months. Empty it, clean it, and store it in the garage or basement if possible.

If this isn’t possible (and after all, we’ve already told you to store your grill, patio furniture, and all your main yard equipment in the garage over winter – it may be getting a bit crowded in there!), you can disconnect it from the gutter and cover it with a tarp. Turn it upside down first.

How Do You Make a Cheap Rain Barrel?

You can make your own rain barrel for as little as ten dollars. We were very impressed with this short video by OikoEco, which takes you through the simple steps of making a simple rain barrel for just a few bucks.

He uses a cheap garbage can as the barrel, and repurposes a spigot from an old beer brewing kit. Be prepared to drill holes and patch up minor leaks! But basically, using a garbage can is a great way to make a no-frills rain barrel.

Does Rain Barrel Water Go Bad?

It doesn’t really go “bad” (water doesn’t have a use-by date, but rain barrel water can, and will, become stagnant if left too long. It can grow algae and mold, and this is when mosquitos move in to use your barrel as their perfect nursery.

Hopefully, you’ll be using it as quickly as the barrel collects it, keeping all your plants nice and watered. If not, you’ll need to clean out your barrel occasionally to prevent the water from becoming too stagnant.

How Do You Keep Rain Barrel Water Fresh?

The best way to keep the water fresh is to keep using it, so you have a constant input and output of fresh rainwater. However, you’ll still need to clean out the barrel from time to time.

The best thing to clean it with is our old friend, baking soda. We really don’t want to be using any nasty chemicals in our water barrels. Drain the water, and give the barrel a good scrub with the soda.

Clean all parts, including the pipes (and if it’s safe, clean the gutter that feeds the barrel, too). When it’s done, rinse it well with some fresh water from the faucet or hose. Resemble the barrel, and you’re all set to resume rainwater harvesting.

What is a Good Size Rain Barrel?

The typical barrel is around 55 gallons. This is enough for most households, and it’s a neat size for the standard yard. Because this is the standard size, it’s easy to buy spare fixtures and fittings for a 55-gallon model.

Is One Rain Barrel Enough? (How Many Rain Barrels Should I Get?)

This depends on the size of your roof, the amount of rainfall you get, and how much water you plan to harvest. If you fit a barrel, then realize that it could be collecting a lot more water, it’s pretty straightforward to join two barrels together.

We’ve also come across folk who have installed barrels for each roof or large section of roof, to make the most of the run-off from more guttering. For example, you could have a barrel that uses the gutter from your home, and a second that collects the garage roof rainfall.

How Do I Keep Mold & Bacteria Out of My Rain Barrel?

The best way to prevent mold and bacteria from developing in your rain barrel is to give it thorough and regular cleans. Use fresh water and bicarbonate of soda at least twice a year, and always give it a thorough scrub before you winterize it.

Just remember that you need to clean every single part of the system, even the fiddly pipes, faucet, and regulator.

Do Rain Barrels Help With Drainage?

Definitely yes. Rain barrels are another way to take charge of where stormwater goes, along with downspout extenders and French drains.

Can You Use a Garden Hose on a Rain Barrel?

Yup. Most rain barrels are fitted with a standard garden hose-sized spigot. The water pressure coming out of your barrel should be fine for a regular garden hose. If you use a pump, you may want to use a high-pressure hose from the barrel to the pump.

Can You Use a Sprinkler With a Rain Barrel?

Yes, but keep in mind that sprinklers use a lot of water, so rain barrels may not be the best solution. An average single sprinkler can shoot out up to 5 gallons of water every minute. That means that your 60-gallon rain barrel will last for 12 minutes.

Water conservationists say that sprinklers waste up to 80% of the water they use, just through evaporation. If you use a drip system or a soaker hose system, you’ll make better use of your precious water barrel water. 

Do Soaker Hoses Work With Rain Barrels?

Yes. Soaker hoses work well with rain barrels. Use a regular hose to get across the lawn over to a garden bed and then snake a soaker hose through your blooms.

Don’t forget – gravity is the law. Make sure your garden area is downhill from your barrels, or use a pump on a low setting to get your soaker hose system going. And, to avoid all those soaker holes filling with debris, consider adding a screen filter inside your barrel.

How Much Rain Water Comes Off a Roof?

There are calculators for that. You’ll need three inputs: the length and width of your roof and then the inches of rainfall. 

Here’s an example: let’s say that you have a 2,300-square-foot house with two stories. Your roof would have a square footage of around 1,500. Then, let’s say you live in Louisiana, where you may have a gully washing 4 inches of rain in a day. 

That’s a total of 3,750 gallons of water. If you have four downspouts, then 900 gallons of rain will shoot down each downspout.

How High Off the Ground Should a Rain Barrel Be?

Rain barrels should be at least two feet above the highest spot in your garden. That way, you should be able to drain the barrel to its last drop.

Does a Rain Barrel Have to Be Attached to a Gutter?

Nope. Attaching a rain barrel to a gutter is the most efficient method, but not the only one. 

The next time you have good rain, walk around your house. Even if you don’t have a gutter system, there will be spots where rain tends to run down the heaviest – that’s the spot for your barrel.

Can You Fill a Rain Barrel From the Bottom?

Surprisingly, upside-down rain barrels are a thing, with plenty of websites and videos to show you how to DIY your own system. The advantages are: no openings for breeding mosquitoes and a surefire overflow system.

The system consists of a series of vertical and horizontal pipes (or hoses) running from a diverter on the downspout into a barrel or series of barrels. Water fills the series of pipes and then the barrels from the bottom up. Finally, a diverter makes sure the barrel doesn’t overflow.

How Do I Water My Plants With a Rain Barrel?

Let’s face it – rain barrels probably won’t cut it for watering acres of grass. But rain barrels are ideal for flower beds, flower pots and vegetable gardens. Most gardeners just use watering cans, but you can set up soaker hoses or drip irrigation systems too.

Here’s a rule of thumb: for a 10-foot by 10-foot vegetable garden. For optimum plant health, that sized garden needs one inch of rain per week. For that sized garden, one inch of rain is approximately equal to one 60-gallon rain barrel.

What Color Should Rain Barrels Be?

Many rain barrels on the market today are made from a composite material or plastic. You can paint plastic to match your house or trim. You can paint them with whimsical flowers and rainbows. Clownfish. Or, paint it to look like a whiskey barrel. Or…

Anything, really, except solid black or solid white. You should avoid solid black because it will absorb heat in the summer – the water you use on your veggies may be too hot. Solid white rain barrels tend to be too opaque and you may develop an algae problem.

Do Downspout Diverters Work With Rain Barrels?

Yes. Downspout diverters automatically route rainwater to your downspout once your rain barrel fills up. They are cheap (around $40) and may protect your basement and foundation from overflowing rainwater.

A common rain barrel complaint is that the overflow hoses are too small. A good downpour can overrun the small hose and then all that water streams down the sides of the barrel and runs down along your foundation.

With a diverter installed, overflow water will flow down the downspout, where you can run an extension or feed it into a French drain.

What is The Best Rain Barrel On The Market? (And Where Can I Buy One?)

You can buy decent rain barrels at stores like Lowe’s and Home Depot, and there’s a good selection on Amazon. 

This rain barrel from RTS (click here to check out the latest prices at collects 50 gallons, is made from recycled materials, costs just under $100, and is very well rated on Amazon (4.5 stars from 1600 reviews). You can get a collapsible rain barrel for half this price, and it’s a good option if you plan to use it for only a few months of the year.

Final Thoughts

I hope this article answers all your questions about rain barrels – it never ceases to amaze me how much you can learn about the most simple thing if you start doing a bit of digging!

Just don’t use one to harvest rainwater in Colorado as it’s illegal!

For my part, I think we’ll choose some rain barrels made from recycled materials like the one above. After all, we like to try and do our bit for the environment here at Take a Yard. 🙂

Mark H.

Homeowner and property investor Mark H. aspires to bring you the very best outdoor living content, based on his years of experience managing outside spaces. Read more >