What Is a Rain Barrel and How Does It Work?

Posted by
Cameron Wise on March 03, 2023

Throughout history, humans have valued the idea of conserving rainwater to use at a later time. 2000 years ago, residents of Thailand collected rainwater in clay pots to use for their homes. About 500 years later, a massive rainwater tank was created in Turkey that held up to 21 million gallons of rainwater. This tank was used to disperse water to the citizens of Istanbul. Because we have robust city water systems today, collecting rainwater may seem obsolete, but doing so can save you money, keep your plants healthy, and help the environment. Below you can find information on what a rain barrel is, how it works, how to maintain one, and the advantages and disadvantages of owning one.

What is a rain barrel?

A rain barrel is a storage container used to collect rainwater. Also known as a water storage tank, it gathers water from your roof that would otherwise be lost to storm drains and streams. The collected water can then be used for various applications, such as watering your lawn, cleaning outdoor surfaces, and gardening. Rain barrels are commonly made of plastic but can also be made from wood, stone, or clay.

How does a rain barrel work?

Rain barrels attach to downspouts with a diverter installed directly on the downspout. Once the water is diverted into the barrel, a hose or spigot can be attached to disperse the water for various uses. Common uses for rainwater include irrigation, watering inedible plants, and washing exterior surfaces like cars and doghouses.

Rain barrels come in many sizes, from as small as 50 gallons to as large as thousands of gallons. A 500 square foot roof can fill a 50-gallon rain barrel with as little as 1/8 of an inch of rain, so rain barrels are effective even for areas experiencing drought. Since such a small amount of rain can fill a rain barrel effectively, rain barrels are an excellent choice for areas where rainfall is limited.

How do I use a rain barrel?

  1. Rain barrels can be placed near the downspout that is most convenient for you. If one of your downspouts drains more water than others, you will want to locate your barrel near that downspout.
  2. Attach a diverter to the downspout and the top of your barrel. These block sunlight from the stored water and seals the barrel from mosquitos, pests, and algae.
  3. Connect a hose or spigot to the barrel to use the collected rainwater.
  4. Clean your barrel at least once a year.

You can use water from your rain barrel for a variety of applications, but you should not use it for drinking without a proper filtration system in place. Rainwater is best used for outdoor applications such as watering your lawn and washing outdoor surfaces. Rainwater harvesting can also provide a solution to those living off the grid with no access to city or well water.

Is using a rain barrel legal?

Before purchasing a rain barrel, you will want to check if using one is legal in your area. Some state laws may prevent you from collecting rainwater entirely, and others have regulations in place. Here are the restrictions for all 48 contiguous states.

Colorado – Rainwater harvesting is illegal.

Idaho – You can harvest rainwater off a roof if rain has not entered a natural waterway.

Ohio – Rainwater harvesting is legal if the water system is providing drinking water to fewer than 25 people.

Oregon – Rainwater harvesting is legal but only from rooftops.

Utah – You can harvest a maximum of 2500 gallons of rainwater.

Every other state – Rainwater harvesting is legal and unrestricted, sometimes even encouraged.

rain in gutters

Advantages of using a rain barrel

Rain barrels are excellent at storing free water for certain applications. Rain barrels come with the following benefits:

  • They reduce your water bill. Since storage tanks can hold from dozens to hundreds of gallons of water, you can save a substantial amount of money depending on how often you use your stored water. If you go through a large amount of water for outdoor uses, rain barrels are a worthwhile
  • They are beneficial for plant health. Rainwater is highly oxygenated and does not contain contaminants, such as salts and fluoride, that city water does. Watering your plants with rainwater also makes them more resistant to drought.
  • They conserve water during droughts. 1 inch of rain can run hundreds of gallons of water off an average-sized roof. If you live in a place that is prone to drought, rain barrels will help you save water when the supply is low.
  • They are excellent at storing water for washing your car. Rainwater does not contain elements that make water hard. Hard water can damage paint, so it is perfect for washing your car without stripping its paint.
  • They are environmentally friendly. Rainwater harvesting is great for the environment because it is sustainable, reduces waste, and does not use any energy. Rainwater can collect toxic chemicals and contaminate streams and water supplies, so collecting it prevents toxic runoff from reaching those sources.

Disadvantages of using a rain barrel

While there are many advantages to using rain barrels, they do come with some disadvantages. The following are some negative aspects to rain barrels:

  • They can be hard to fill up during the dry season. While a single rainfall can fill even a large storage tank, you can run out of water for your garden if rainfall is sparse. To combat this, you may need to invest in a larger rain barrel to ensure you do not run out of water.
  • The water they collect is not safe to drink. When rain falls, it collects contaminants from the air and eventually from your rooftop as it drains into the gutters. Bird waste, insects, leaves, and other contaminants make rainwater unsafe to drink. You can connect a rain barrel to water filters that make it safe to drink, but that comes at extra cost.
  • They may not collect enough water for your purposes, meaning you will need to purchase more than one barrel. Collecting water from multiple downspouts will improve your collection capacity, but it will come at extra cost.
  • In cold climates, water in a storage tank can freeze and crack the container. If weather in your area is subject to freezing, you will need to drain your rain barrel and store it during the winter months.

Types of rain barrels

Rain barrels can be made from numerous materials, and they all serve different purposes.

  • Plastic rain barrels are the cheapest and easiest type to clean. The downside of plastic barrels is that they are often not the most attractive looking type. Because of their cheapness and ease of maintenance, they are by far the most popular option.
  • Stone and clay rain barrels are typically much smaller than their plastic and wooden counterparts. They are often chosen for their aesthetic addition to a garden.
  • Wooden rain barrels can be made from oak, cedar, hickory, or other types of wood. They are chosen over plastic for their rustic appeal. However, their aesthetic comes at the cost of more difficult cleaning.

Do I need to clean my rain barrel?

Yes, rain barrels need to be cleaned at least once a year to prevent algae and bacterial growth. Cleaning also allows you to test the functionality of your downspout and the condition of your rain barrel.

How to clean a rain barrel

  1. Drain the barrel and disconnect it from the downspout.
  2. Clean the gutter that drains water into the barrel. You can run water through the gutter to ensure it is draining properly.
  3. Clear out debris from your downspout filters. Clogged downspout filters can prevent water from efficiently flowing to your storage tank.
  4. Rinse the mesh screen on your rain barrel. This prevents insects and other debris from entering stored water.
  5. Ensure that no cracks or structurally compromising damage are present in the barrel. Cracks can not only cause leaks; they can allow outside contaminants to enter the stored water.
  6. Lay the barrel sideways and rinse its interior.
  7. Scrub the inside of the barrel using a cleaning product. Vinegar, bleach, and dish soap are all effective cleaning products.
  8. Remove the cleaning agent from your tank. Rinse the interior thoroughly to guarantee future stored water is not contaminated.
  9. Allow the barrel to dry and reconnect it to the downspout diverter.

rain on roof

What is the best rain barrel?

Best small rain barrel

The 165 Gallon Norwesco Vertical Tank is an excellent low-capacity option for your home. It is made from polyethylene, a material that meets the FDA standards for potable water storage. Its dark color blends in with the environment and shields the interior from the sun. This tank can also withstand long-term exposure to harsh weather conditions and ultraviolet rays from the sun.

Best medium rain barrel

The 500 Gallon Above Ground Tank by Norwesco is a great medium-capacity tank for your yard. It comes in a green color that will blend in with nature and make it more aesthetically pleasing. Like the 165-gallon option, it is made of polyethylene and will not be damaged by harsh weather or ultraviolet rays.

Best large rain barrel

The 2500 Gallon Above Ground Tank by Norwesco is a perfect large storage tank option. Designed for large-scale water conservation, it is 91 inches tall and 95 inches in diameter. Like the 500-gallon option, its color allows it to blend into the environment, and it will protect both water and the tank itself from harsh weather and sunlight.

Is rainwater safe to drink?

No, rainwater is not safe to drink without a proper filtration system in place. Water collects contaminants, such as bird waste, dirt, and insects, as it runs off your roof. Even rainwater that does not contact your roof can contain harmful pollutants collected from the air.

A water filtration system can be connected to a rain barrel and piped directly into a home, or you can fill a gravity-fed filter with rainwater. However, adding and maintaining a filtration system to your home is often a more expensive option than filtering city-treated water. Since you need a filter for your tap water anyways, adding another one to save on water costs may be counterintuitive depending on your situation. If you need to use rainwater for drinking, a gravity-fed container is the best economical choice. For those living off the grid, harvesting rainwater is the most sustainable, affordable, and environmentally friendly option.

Learn more: How to Collect Rainwater for Drinking

Can I use rainwater for my garden?

Yes, you can use rainwater for your garden, but you will want to be careful if you use it for edible plants. If you want to use rainwater directly from the barrel to edible plants, you will need to have a system that puts the water directly into the soil. Letting the water touch the plants will expose them to potentially harmful contaminants that the water collected on your rooftop. Once your plants ripen, you will need to use filtered water on them to reduce the risk of contamination. Plants that are purely aesthetic greatly benefit from rainwater. Tap water can contain contaminants that are detrimental to plant health, so rainwater is a healthier option for plants that are not edible.



If you have any additional questions, please do not hesitate to contact us.

No comments yet.
Leave a comment