What Is a Rain Barrel?

Three painted rain barrels along the side of a house

A rain barrel is a large container that catches and collects the stormwater flowing from your gutter downspout. Once the barrel collects the water, you can use it for household chores like watering your garden or washing your car. 

Rain barrels help conserve water during drought and keep polluted stormwater runoff out of streams, rivers, and lakes. Want to learn more about this drought-friendly and eco-conscious gardening phenomenon? You’ve come to the right place. 

How a rain barrel works

When it rains, the water that hits your rooftop flows into your gutters and eventually down the downspout. A rain barrel goes directly under the downspout, where it catches all that water from your roof. 

Over time, several gallons of water collect in the barrel. There’s an outlet near the base, where you can attach a spigot or garden hose and access the water for irrigating your lawn and garden, cleaning, or whatever else you plan to use it for.

How a Rain Barrel Works - Downspout, through screen (remove debris), into barrel | Overflow valve close to top |  Spigot close to bottom | Barrel on a stand

Why to use a rain barrel

Rain barrels have many benefits for homeowners and the greater environment, including: 

  • Lowers your water bills
  • Reduces water use 
  • Prevents stormwater runoff carrying pesticides, chemical fertilizers, and other pollutants into natural bodies of water 
  • Reduces risk of flooding and erosion on your property 
  • Provides natural, chlorine-free water for your plants (as opposed to tap water)

The one major downside of rain barrels and other rainwater harvesting methods is that diverting the water from streams, rivers, and lakes has the potential to disrupt local aquatic ecosystems. However, most states limit the amount of water you can collect to prevent any significant negative impact on natural bodies of water. 

On top of all the benefits, rain barrels are easy to install, and you can build one yourself for less than $100 (learn how to build and install one in How to Use a Rain Barrel). So, the real question isn’t, “Why should you use a rain barrel?” — it’s “Why aren’t you using one already?”

Components of a rain barrel 

Rain barrels come in different shapes and sizes — some store-bought, some homemade — but they should all have these basic components. 


The largest and most important piece of the puzzle is the water-collecting container itself. Rain barrels you buy from the store usually hold 45 to 65 gallons of water, and they come in a wide selection of styles and colors. You can choose between a rigid barrel or a soft, collapsible container for easier storage in winter. 

If you’re looking to save money, you also can create your own rain barrel system using a large plastic drum or outdoor trash can. Keep in mind, though, that plastic drums large enough to function as rain barrels can be expensive, too. 

Downspout connection

When you install a rain barrel under a downspout, you’ll probably need to make some sort of adjustment to help the water reach the barrel. 

Options for connecting the rain barrel to the downspout include:

  • Cutting the downspout: Your downspout likely reaches all the way to the ground. You can saw off a portion of the downspout so that it ends just above the rain barrel instead. 
  • Rain barrel diverter: A rain barrel diverter is a small pipe that reaches from the middle of the downspout to the rain barrel, so you don’t have to cut the downspout. With a diverter, you can keep a closed lid on your barrel so it doesn’t attract mosquitoes. Diverters also help regulate the barrel’s water intake, so you may not need an overflow valve. 
  • Downspout extension or elbow pipe: If you can’t place your rain barrel directly under the downspout itself, use a bent downspout extension or an elbow-shaped length of PVC pipe to direct the water to the barrel. 

Whatever kind of downspout connection you use, the point is to make sure the water flows into your rain barrel without splashing or leaking onto the ground, where it could damage your home’s foundation. 

Water outlet 

The water outlet is how you get collected rainwater out of the barrel so you can use it. The outlet should be close to the bottom of the barrel so you have access to the most water possible. You can attach a spigot for filling watering cans and buckets or attach a garden hose directly to the water outlet. 

While the water pressure from a rain barrel isn’t enough to power traditional sprinklers, you may be able to hook up a successful drip irrigation system to the water outlet. 

Note: If you’re going to use the rain barrel to fill watering cans or buckets, make sure the spigot is high enough off the ground that the container you want to fill can fit underneath it. 

Overflow system

Measures put in place to keep a rain barrel from overflowing are called the overflow system. You don’t want your rain barrel to overflow because the excess water will flood the surrounding area, potentially damaging your home’s foundation, killing your grass, and attracting pests. 

An overflow system can be as simple as a short length of PVC pipe directing the flow of excess water away from your home. If you have the means, you can install a longer overflow pipe or hose that carries excess water directly to the nearest storm drain. You also can connect the overflow valve to a second rain barrel to collect more water. 


Your rain barrel needs to sit on perfectly flat, even ground to keep it from spilling or tipping over. There are two ways to achieve this:

  • Place your rain barrel on a raised platform made of plastic or cinder blocks. The platform should be strong enough to hold the barrel when it’s full of water, which could weigh more than 300 pounds, depending on its size. Elevating the barrel on a platform increases the water pressure for a faster flow rate. 
  • Dig a 1 to 2 inch pit and fill it with sand or gravel, smoothing the top of the surface. Place your barrel on top of the layer of sand or gravel. 

If you plan to hook your rain barrel up to a hose or drip irrigation system, it’s best to elevate it on a platform for the increased flow rate. 

Types of rain barrel lids 

There are two main categories of rain barrel lids: opening lids vs. closed lids. 

Opening lids allow water to flow directly into the top of the barrel from the downspout. They also give you quick and easy access to the water without having to use the spigot. An open-lid rain barrel needs a protective debris screen to keep out leaves, twigs, animals, and especially mosquitoes, which are attracted to standing water. 

Closed lids are more secure and better at keeping out curious animals or small children. They also prevent mosquitoes laying eggs in your rain barrel. With a closed lid, you would have to use a diverter to get water from your downspout to the barrel. 

Design tip: Some gardeners use closed rain barrel lids as planters to liven up the look of the barrel and help it blend into the aesthetic of the landscape. 

Where to get a rain barrel

As we already mentioned, you can build your own rain barrel or buy one from the store. You should be able to find a selection of rain barrels at your local hardware store or garden supply center. If not, you can purchase them online from big-box stores like Lowe’s and Home Depot. 

If your local government encourages rainwater harvesting, it may offer rain barrels at discount prices or even for free. You’re more likely to find a state-sponsored rain barrel program if you live in a drought-prone area. 

Search “free rain barrels” or “rain barrel giveaway” and the name of your city online to find out if your local government offers such a program. The EPA has local resources on their website for Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. 

Uses for rain barrel water (and when not to use it)

As stormwater runoff travels down your roof, it can pick up chemicals or sediment from the roofing material and bacteria left behind by wild animals. Since the water isn’t treated before you use it, it isn’t “potable,” which means it’s only safe for certain uses. 

What to use rain barrel water for:

  • Watering your lawn and garden
  • Watering houseplants
  • Washing your car 
  • Mopping your floors 
  • Cleaning your patio, deck, or driveway

What NOT to use rain barrel water for:

  • Drinking
  • Cooking 
  • Bathing
  • Cleaning surfaces that come into contact with food 

Note: Whether you should use rain barrel water on vegetable gardens and fruit plants is debatable, since you’ll eat the produce. If you choose to use it, only pour it on the soil and make sure it doesn’t get on the plants themselves.  

FAQ about rain barrels

1. How much water does a rain barrel save?

For every inch of rainfall, a rain barrel collects about half a gallon of water per square foot of roof (not the whole roof, but only the section that drains into that particular downspout). 

So, if your area gets 30 inches of rainfall this year and 300 square feet of your roof drain into one downspout, your rain barrel could collect up to 4,500 gallons of water over the course of the year. That’s 4,500 gallons of water you don’t have to pay for!

2. What is the average price for a rain barrel?

Store-bought rain barrel kits typically cost about $100-$200, depending on the size and style. 

The supplies for a DIY rain barrel cost about $72-$130, assuming you don’t already have everything you need and have to buy it all new. Here’s how that cost breaks down: 

44 to 55-gallon plastic trash can: $40- $70
Downspout flex-elbow: $3-$5 
6-inch atrium grate: $4-$7
Sump pump drain hose kit: $9-$15
¾-inch spigot with sillcock: $6-$12 
1 ¼-inch PVC female adapter: $1-$2
¾-inch PVC male adapter: $1-$2
Silicone caulk: $5-$10 
Plumbing tape: $1-$3
2 cinder blocks (for raised platform): $2-$4  

3. Why is it illegal to have a rain barrel in some places?

Rainwater collection is currently legal in all 50 states, although several states have restrictions on how much water you can collect and what you can do with it. However, your city, town, or homeowners association might ban rainwater harvesting, so check local laws before installing a rain barrel. 

Restrictions like these exist because of the drawback we discussed earlier, the possibility that saving rainwater might disrupt aquatic ecosystems. In some Western states, the restrictions have to do with old water rights laws that date back to the Gold Rush in the mid-19th century.

Find more information here on state-by-state rainwater harvesting regulations.

More eco-friendly landscaping tips 

Installing a rain barrel can go a long way in reducing your lawn and landscape’s carbon footprint. But it’s just one step on a longer road to making your outdoor spaces as eco-friendly as possible. 

Check out Lawn Love’s sustainable landscape design ideas, which include:

  • Choose low-maintenance, water-saving native plants 
  • Replace turfgrass with ground cover plants or permeable hardscapes such as gravel 
  • Use solar-powered lighting 
  • Provide pollen and nectar-rich flowers for bees, butterflies, and other pollinators
  • Build a vertical garden along the wall of your home for added insulation 
  • Compost grass clippings, yard debris, and food scraps to reduce waste

Follow these tips to waste less water and energy on your landscape. Your wallet and your environment will thank you.

Need help implementing and maintaining your eco-friendly landscape? Lawn Love’s local lawn care and landscaping pros can mow the lawn, fertilize, pull weeds, and more.  

Main Photo Credit: CityofStPete | Flickr | CC BY-ND 2.0

Jordan Ardoin

Jordan Ardoin is a writer and editor with a passion for sustainable, earth-friendly gardening and lawn care practices. When she isn't sharing her knowledge about lawn care and landscaping, you can find her curled up with a good book and a cat in her lap.