Rain Barrels: How To Collect Rain Water

Updated: Aug. 29, 2023

Rain barrels are fairly easy to set up and can provide benefits to you and the environment. Here are some expert tips on how to collect rainwater.

Although you may have only recently noticed rain barrels popping up around your neighborhood, the concept has been around for thousands of years. There’s archeological evidence of rainwater capture as far back as 4,000 years ago!

And while the materials used to make the rain barrels have changed, the purpose is the same: to collect a natural resource for outdoor use.

Before you run out to buy or build a rain barrel, read these tips from the experts about rain barrels.

What Is a Rain Barrel?

Sometimes rain barrels are mistaken for wine barrels or purely decorative lawn ornaments, but they serve a distinct purpose. Rain barrels collect rainwater that flows from roof gutters for non-potable uses, like watering plants. They’re typically placed below a downspout. They usually have a spigot near the bottom to attach a hose.

How To Collect Rain Water Using a Rain Barrel

Here are a few important — and some surprising — expert tips for setting up and maintaining your rain barrel:

  • Check local laws: Andre Kazimierski, a rain barrel enthusiast and CEO of Improovy Painters St Louis says, “In some places, it may be illegal to collect water in a rain barrel. So this is the first thing to consider.” In places where it is legal, there may be restrictions, like a cap on the amount of water collected. So check with your municipality before setting up your rain barrel.

  • Consider local conditions: If you live in an area without consistent rainfall, rain barrels may not work as well for you. Jeremy Yamaguchi, the CEO of Lawn Love, says some of his colleagues who live in the Pacific Northwest use rain barrels as the primary water source for their gardens. But when he installed rain barrels at his home in California, he says it wasn’t as successful, “simply because it never rains!”

  • Pay attention to placement: “Water weighs about eight pounds per gallon, so a 50-gallon drum would weigh around 400 pounds when full,” says Tristan Grant, sustainability director at the energy efficiency consulting firm MaGrann Associates. “You need to be sure the surface it’s mounted on is level and can support the additional weight.” You can even collect water into your barrel with a rain chain.

  • Create a path for overflow: “Be careful that you don’t create a bulk water issue around the foundation of your home by causing overflow to build up near the base of a building and/or overflow onto windows, siding, etc,” Grant says. “Bulk water can cause serious damage to a home.” Grant says you should maintain a clear path for the overflow during the setup phase. “This can usually be accomplished with an overflow opening that connects to another gutter spout that takes the water to another rain barrel in sequence downhill, or otherwise discharges the water where the gutter would have naturally taken it,” he says.

  • Ensure rain barrels are covered properly: Avoid the mistake Todd Saunders, CEO of FlooringStores, says he made when he set up rain barrels at the downspouts of his cabin. “I was very proud of myself until one day I saw thousands of things wriggling near the surface of the water,” he says. “I figured out what they were a day or two later; our yard was swarmed by more mosquitoes than I’ve ever seen in one place in my life.” Covering your barrels stops mosquitoes from breeding while preventing evaporation.

  • Be mindful of build-up: Even if you’re only using the water for plants, cycle the water regularly to avoid bacteria buildup. Leonard Ang, CEO of iPropertyManagement, recommends thorough cleaning at least once a year. Grant says you should also empty filters regularly so water doesn’t back up and overflow outside of the planned drainage pathways. Cleaning frequency depends on your local conditions. “Expect to change them more during certain seasons, such as spring and fall when leaves are dropping or pollen and flowering trees drop seed pods,” he says.

  • Give the rain barrels a winter break. If you live where freezing temperatures are possible, Grant suggests emptying the barrels before the cold hits to prevent freezing and expansion damage.

What Are the Benefits of a Rain Barrel?

There are lots of benefits to the environment and the user:

  • Save money and reduce reliance on municipal sources: Davin Eberhardt, the founder of home improvement blog Nature of Home, says rain barrels can help you save money on your water bill. The amount will vary depending on your usage and local water costs. It also ensures you have water on hand during times of drought.

  • Reduce erosion and your carbon footprint.  Eberhardt says when you use your rain barrel water rather than turning on your faucet or hose, you lower your energy demands because it doesn’t require moving and treating the water like municipal water systems do. Ang adds you’re also curbing erosion and keeping runoff from ending up in the sewer systems.

  • Help protect natural waterways. During bad weather, Grant says capturing rainwater can alleviate pressure on local water systems. “When a stormwater treatment plant is overwhelmed and unable to treat the incoming water and sewage as fast as it comes in, it gets dumped into a local body of water (river, coastline, ocean) untreated,” Grant says. “This is obviously not ideal for a number of reasons, including the pollution of local water resources, which is both bad for people who may use those areas for recreation and also bad for the local environment.”

  • Replenish local aquifers. Grant says human development altered natural landscapes by adding surfaces rain can’t penetrate (driveways, sidewalks, roofs, etc). “Oftentimes, it flows down the driveway, to a street, and enters the stormwater system, where it is taken further away and typically terminates in a river, lake, or ocean,” he says. “This means less water for plants, and ultimately less water replenishing the local aquifers.” Watering your plants from a rain barrel allows the water to be distributed into local aquifers.

What Can the Water Be Used For?

Besides watering plants and flowers, our experts suggested these non-potable uses:

  • Washing cars, windows, patios and other outdoor surfaces. “Rainwater typically has a neutral pH level, making it perfect for washing cars,” Eberhardt says.
  • Refilling bird baths, koi ponds, water features and swimming pools.

  • Rinsing your garden tools and shoes.

  • Flushing toilets.

  • Keeping compost bins moist.

How Much Does a Rain Barrel Cost?

The cost of a rain barrel tends to fall in between $100 and $300. You can also build a rain barrel for less than $100.

But before you buy or build, Eberhardt recommends checking with local officials. Some cities, counties or states offer incentives, tax credits, and programs that provide free rain barrels.

Another possibility: Grant suggests scouring Craigslist and other community marketplaces where people sell barrels at discounted prices. You can also check Buy Nothing groups to see if anyone is offering one for free. Just be sure you know what the barrel was used for.

“Food storage barrels and certain mineral compounds like salt or sand would be fine,” Grant says. “But you should avoid barrels that were used to store oil or toxic chemicals.”