What Is A Rain Barrel And Can It Actually Save You Money?

Harvesting rainwater has many benefits.

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Updated on January 25, 2024

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Water is essential for life. Your plants need water to grow and thrive, and more during the hotter months. Ever wondered about catching rain to use during times when there is less or no rain? Installing a rain barrel allows you to do exactly that: collect and store a natural resource for later use. Harvesting rainwater has many benefits from saving money on your water bill to utilizing what freely falls from the sky for times when raindrops aren’t so abundant.

Rainwater for Watering Plants — Getty Images

What is a Rain Barrel?

A rain barrel is a container that collects and stores rainwater. There are many different styles of rain barrels and ways to install them. Oftentimes, the rainwater comes from the top of a roof or passes through gutters but there are various formats. “Rainwater can be directed into rain barrels using a rain chain or simple sheet flow from the roof if no gutters or downspouts are available,” says Ellen Sturup Comeau, water resources agent, Clemson University Cooperative Extension.

Ellen Sturup Comeau is the water resources agent at Clemson University Cooperative Extension.
Ashly Tamayo is the director of education at Recipe for Success Foundation and Hope Farms, based in Houston, Texas.

Choosing a Rain Barrel

Rain barrels are made with different types of materials, including metal and fiberglass but for most homeowners, opting for a plastic rain barrel will make the most sense. “The most popular choice is plastic for cost, quality, ease of use, and availability,” says Ashly Tamayo, director of education at Recipe for Success and Hope Farms, based in Houston, Texas. You also want to ensure that light can’t get in so choosing a dark, opaque color is important, she adds. Both experts recommend choosing a barrel made with food-grade plastic.

When choosing a rain barrel, you want to make sure it has a few accessories and a way to access the water easily. According to Comeau, “Every rain barrel should also have a tightly secured lid, a screened inlet, an emergency overflow with a flexible pipe or hose to direct excess water away from structures, and a spigot that can turn on and off.”

Collecting Rainwater Can Save Money on Your Water Bill

Collecting rainwater can be used for your landscaping or cleaning needs, and it's a resource you don't have to get or pay for from the local municipality. “Harvesting rainwater can reduce a gardener’s water bill by reducing the amount of treated water used for irrigation,” says Comeau. “When residents use harvested rainwater to water their gardens, they do not use and do not pay for potable water from the local water utility.”

Depending on the size of your property and how much water you use for irrigation, it’s likely that one rain barrel won’t be sufficient for all your water-related needs but it will help. “An individual rain barrel collects less than 100 gallons of water,” says Sturfup. “This amount of water may satisfy the irrigation requirements for container plants, perennial beds, or select garden areas, but it will not be sufficient for a lawn.”

Homeowners who have plenty of space and want to utilize natural resources as much as possible may want to opt for multiple barrels to capture more water. To provide perspective Comeau provides an example of how much water you can collect based on the roof area and the amount of rainfall. “Each square foot of roof area can generate 0.623 gallons of water for capture in one inch of rain,” she says. “So, for example, a 1,000 square foot roof area could generate over 600 gallons of water for harvesting in a one-inch rainfall.”

How You Can Use Rainwater

Rain water may typically be used for irrigation but there are many ways to use it, such as cleaning or filling up a bird bath. “Residents can use collected rainwater for irrigation, equipment washing, pet washing, and providing water sources for wildlife,” says Comeau. Having your own rainwater can be helpful when there is limited rainfall or reduced access to water sources. “Harvested rainwater can also provide a supplemental water source for landscaping in case of drought, salty wells, or disrupted water supplies.”

Stored Rainwater Isn’t Potable

Water stored in rain barrels is considered non-potable. Although the water that is collected comes from the sky, the way it reaches the container may not make it safe to drink. Plus, the length of time it’s stored can create a haven for algae or pathogens to grow. “Rainwater collected in a rain barrel is non-potable because several pollutants, including pathogens, heavy metals, and pesticides, can accumulate on rooftops and move into rain barrels during a storm event,” says Comeau. This means that any edible plants shouldn’t be watered with stored rainwater to minimize any risks of cross-contamination.

This may seem counterintuitive since rain is beneficial for all plants. “Rainwater is really good for plants [because it has] nitrates, which plants need to grow and thrive,” says Tamayo. “It's the natural way of growing things.” But the way the water enters the barrel may contain pathogens that could cause potential risks to your health. “There are biological contaminants from birds, rodents, animals, like their feces that can be collected [and go] right into your storage tank,” explains Tamayo.

The good news is that stored rainwater isn’t completely off-limits for watering your vegetable garden but it will require extra steps. According to Comeau, “We do not recommend using rain collected in a rain barrel to irrigate fruits, vegetables, and other edible plants without additional design, maintenance, and application strategies.”