Home & Garden Garden How to Set Up a Rain Barrel System at Home: Easy Step-by-Step Instructions By Emma Stenhouse Emma Stenhouse Writer University of Exeter University of Plymouth University of the West of England (Hartpury College) Emma Stenhouse is a marine scientist, educator, and writer with more than 16 years of experience. She holds an M.S. in Marine Science from the University of Plymouth. Learn about our editorial process Published July 30, 2021 Cornelia Pithart / Getty Images Home & Garden Planting Guides Indoor Gardening Urban Farms Insects Overview Total Time: 1 - 2 hours Yield: 1 rain barrel system Estimated Cost: $150 Installing a rain barrel system at home is easy and will help you take advantage of the free water to keep your garden looking healthy. In fact, the water you collect can be used in the same way you’d reuse grey water. You can calculate the exact amount of rainwater you’re likely to collect, but as a rough guide, a 600-square-foot roof will collect around 90 gallons of water from 0.25-inches of rain. Most rainwater barrels have a 55-gallon capacity but you can install multiple barrels to increase your storage. Below is our step-by-step guide for installing a rain barrel system at home. These instructions will work for the majority of rain barrel systems. Many rain barrels kits come with at least some of the items included in our materials list. Rainwater Harvesting Regulations per State Each state enacts its own rainwater harvesting regulations. While some local governments encourage and even incentivize the use of rain barrels, others limit it under health, plumbing, or water usage codes. Before you get started building your rain barrel system, be sure to check the rainwater harvesting regulations for your specific state. Creating a DIY Rain Barrel System zerocattle / Getty Images Our guide will also work if you want to create your own DIY rain barrel system instead of buying a kit. You can use any clean, dark-colored barrel or garbage can with a lid. Lighter-colored barrels aren’t recommended as they don’t block sunlight. This causes algae to grow and results in a distinctive bad smell. If you’re planning on repurposing a barrel make sure it hasn’t been used to store toxic chemicals or anything that could contaminate your water. As well as the steps we’ve listed below, you’ll need to drill some holes in your barrel. We recommend one hole at the bottom for your hose outlet and two at the top as overflow outlets. You’ll also need to cut a hole in the lid as an inlet. Make sure you add screening to prevent insects from gaining access to the water. Insert a drain valve plug into the bottom hole, and attach a hose outlet. For the holes at the top of the barrel, use brass overflow adapters so you can add an overflow hose or connect rain barrels together. What You'll Need Tools Box cutter Needle-nose pliers Screwdriver Sharpie Piece of cardboard Measuring tape Safety glasses Hacksaw Level Trowel (optional) Rubber mallet (optional) Materials Rain barrel Overflow hose Releasable zip ties Overflow cap Ball valve Rubber gasket Screen ring 4-8 paving stones Gravel and sand Downspout elbow and fittings Instructions Choose Your Location You’ll want to place your rain barrel underneath an existing downspout. You may decide to put the rain barrel near your vegetable patch or close to plants that need a lot of water. Make sure there’s enough space underneath your chosen downspout to accommodate a paving stone footing that is larger than the base of your rain barrel. Four 12-inch-by-12-inch paving stones will give you an area of 4 square feet, but you may need a larger base if your rain barrel is bigger than the regular 55-gallons. Prepare the Rain Barrel Footing The footing for your rain barrel needs to be dry and level. Once full of water, a 55-gallon rain barrel will weigh over 400 pounds, so it can tip over if the footing isn’t level. Dig out an area slightly larger than your pavers. Lay sand within this area and use a trowel to spread the sand out evenly. Next, use a level to make sure the sand is as flat as possible. If you want to, you can add an optional layer of gravel at this point. Set your pavers on the sand or gravel and use your level to check they’re flat. If they’re not, either remove your pavers and add more sand, or use a rubber mallet to gently tap the pavers into position. You may choose to add another layer of pavers to elevate your rain barrel and make it easier to attach your hose. If you want to be able to fill a watering can directly from your rain barrel, consider raising the base even further with a stand (just make sure it’s specifically designed to hold the weight of a full rain barrel). Assemble Your Rain Barrel At the bottom of your rain barrel there should be a threaded port. Place the rubber washer into the port and then thread your ball valve tap into the port. Tighten by hand, as using tools can cause overtightening which may damage the thread. If the tap doesn’t point directly upwards once the valve is hand tight, that’s okay. Place the lid on top of your rain barrel. Most water inlets on the lid will have a mesh screen to filter out debris and prevent insects from gaining access to your water. Make sure this is in place on the lid. Some rain barrels come with zip ties to secure the lid as well, so attach these now, too. Measure Where to Cut Downspout Place your rain barrel on the footing you installed underneath your chosen downspout. Hold the new downspout elbow up and rest it on the existing downspout, about 2 inches above the top of the rain barrel inlet. Use a sharpie to make a mark on your downspout, about 2 inches below the top of the elbow. Move the rain barrel away from the footing when you’re ready to cut the downspout. Cut Your Downspout and Attach Elbow Place a piece of cardboard behind the downspout to protect the wall of your home. Wearing your work gloves and safety goggles, use the hacksaw to cut the downspout along the sharpie mark from the previous step. Use needle-nose pliers to gently crimp the four corners of the downspout, so you can fit the elbow. Slide the elbow onto the downspout and use a screwdriver to secure it in place with the screws. NOTE: If your home has heated downspouts (to keep them from freezing in the winter), call a professional to help you with this step. Position Your Rain Barrel Now you’re ready to put your rain barrel in place. Position it on the paving footing, underneath the new elbow. Install Overflow Pipe Most rain barrels will come complete with two overflow outlets, an overflow hose, and an overflow cap. Decide which outlet you want to attach the overflow hose to and place the hose over this outlet. Make sure to direct the hose away from your home. If your rain barrel is positioned near a drain, you can place the hose into this. Use the overflow cap to seal off the remaining outlet on your rain barrel. How to Use Your Rain Barrel System When it next rains, check that the water from your downspout is flowing into the rain barrel correctly. When you need to water your garden, attach a hose to the tap at the bottom of the barrel and make use of all that harvested rainwater! You can also place a watering can underneath the tap if your barrel is high enough off the ground. Additional Options If you’d like to collect more water, you can place more rain barrels at other downspouts around your house. You can also connect multiple rain barrels together. Just extend the footing and link the barrels together using a small piece of hose between the outlet pipes on each barrel. If you live in an earthquake-prone area, it’s a good idea to secure your rain barrel to the wall of your home. Maintenance Check the inlet screen regularly and clear away any debris. Keep the screen in place all the time as otherwise insects can gain access to your water and it can quickly become a breeding ground. If you live in a region with high pollen counts, you’ll need to clean out your barrel after pollen season or the water may begin to smell. Drain the barrel and use a soft brush to clean the inside before reinstalling it. All rain barrels need cleaning once a year to remove any organic matter or algae built-up on the sides. At the same time, clean and inspect the screen ring over the inlet. Replace the screen if it’s damaged. Over winter, you may decide to disconnect your rain barrel and store it in a dry area until spring. Frequently Asked Questions Is a DIY rain barrel system cheaper than buying a kit? Using standard household tools and a basic drum, DIY rain barrel systems can cost as little as $20 to $50. A kit, on the other hand, can cost $150 to $300. Should you DIY your rain barrel system or use a kit? If you're a seasoned DIYer with plenty of tools and possibly even some PVC piping lying around at home, then, by all means, make your own rain barrel system. If you feel you may need more direction, buying a kit could be worth the extra cost. Is rain barrel water safe to drink? Sadly, rainwater is not safe to drink because the barrels themselves can harbor bacteria and algae without filtration systems. So long as the barrels are cleaned annually, though, the water should be clean enough to irrigate a vegetable garden. How much does it have to rain to fill a rain barrel? The rule of thumb is this: In a storm where an eighth-inch of rain is falling per hour (standard for a moderate storm) on a 500 square-foot roof, your 50-gallon rain barrel will be full after roughly one hour.