DIY Rain Barrel System: The Complete Guide

Over the past few years, Eric and I have been experimenting with DIY rain barrels. We’ve tried a few different connectors as we fought off several leaks. After some troubleshooting, we have finalized our rain barrel system.

It’s an ambitious system with not one but five 55-gallon barrels connected in a row. Each barrel has a shutoff valve, so we can disperse water equally between the barrels or shut off individual barrels as needed. And we can water our veggies for free all summer long.

Now that we’ve worked out the bugs, we’re ready to share the tutorial. These 12 steps are everything you need to set up your own DIY rain barrel system. And while five barrels may seem overwhelming, the steps are simple, and you can even downsize to fewer barrels as appropriate for your garden. You can totally do this.

Note: This article contains affiliate links. See my disclosures for details.

Basic Rain Barrel Layout

Before we get started, here’s the basic layout to help you see how we’ll put this together. Be sure to check your local laws, because some places may not allow rainwater harvesting. Also note that this rain barrel tutorial is meant for watering thirsty plants, not thirsty people. OK, let’s dive into each step!

DIY rain barrel system sketch

Rain Barrel Guide

1. Gather Materials

Here are the materials you’ll need for a 5-barrel setup. If you want a system with fewer than five barrels, subtract a drain valve plug kit, water hose outlet, hose adapter and tee connector per barrel. Five barrels can water our two raised garden beds over the summer, but not a whole yard of flowers, so it depends on your watering needs.

You can find food grade barrels online, but I recommend you check Craigslist first. Try searching for rain barrels or 55-gallon drums. Make sure the barrels are food grade and have no holes except for the standard two holes on top.

Food companies sometimes sell previously used food storage barrels for around $20 each on Craigslist or through other local classifieds, and these barrels work perfectly. They may have a food smell at first, like the strong pickle smell ours had. You can give them a quick rinse with soapy water, but anyway the plants won’t mind.

2. Prep the Area for Rain Barrels

One thing we learned with our first system is that gravity is your friend when it comes to rain barrels. Look for a spot where you can place your barrels next to a gutter downspout and above your garden, so the water can flow down to your garden with force.

If you don’t already have an elevated area for your rain barrels, you can create one with foundation blocks. Spread sand or gravel to create a level area large enough to hold all of your barrels in a row. Then lay foundation blocks two wide and one or two tall for each barrel.

Rain barrel system on concrete blocks

3. Cut Holes in Barrels

Use your drill and hole saw to cut a 1-3/8-inch hole two inches from the bottom in the front of each barrel. You want these holes low to the ground so your barrels can disperse as much water as possible.

Your first barrel, which will have the watering hose, will need two drain valve plug kits. Cut the second hole in your first barrel two inches from the bottom in the spot where you want your hose to be located to best access your garden.

Note: Putting the valves two inches from the bottom only works if your barrels will be elevated. If you opt to have your barrels flush with the ground, you may need to insert the valves up a few inches so the attachments can fit under the valves.

4. Insert Drain Valve Plugs

Insert a drain valve plug into each of the rain barrel holes you cut. These have rubber gaskets to make them water tight, and they thread backwards so that all other connectors won’t loosen them up. Pretty smart.

Here's how the rain barrel connector pieces snap together
Here’s how the pieces will snap together.

5. Put the Rain Barrels in Place

Set the barrels in your prepared area in a row with the valve plugs facing forward. Make sure they are relatively level. Otherwise, add more sand and adjust the foundation blocks as needed to level out the barrels.

6. Connect Hose Outlets

Now you can start snapping the system together following the sketch and photo above. Wrap pipe tape around both threads of each hose outlet. Insert them into the valve plugs.

7. Connect Hose Adapters

Attach a hose adapter to each of the front center hose outlets (not the outlet where you will attach the garden hose).

8. Add Elbow Connectors

Cut a two-inch piece of tubing and insert it into one side of a snap-fit elbow connector. Then push the other end of the tube piece into the hose adapter of the first barrel. The two-inch tube piece acts as a connector between the hose adapter and elbow. Repeat this step for the last barrel. Make sure to cut the tube pieces squarely to get a functioning snap fit.

Multiple rain barrel system with elbow connector pieces and tubing

9. Add Tee Connectors

Cut a two-inch piece of tubing and insert it into the middle of a snap-fit tee connector. Then push the other end of the tube piece into the hose adapter of your second barrel. Repeat this step for the rest of your middle barrels.

10. Insert Tubing

Measure the distances between your elbows and tees. Cut the poly tubing into pieces two inches longer than each distance, and insert the tubing between the connectors. For five barrels, you should have four cut tubes (one between each barrel). So you’ll have a tube running from elbow to tee, then tee to tee, then tee to tee, and then tee to elbow.

Tubing and connectors between rain barrels

11. Connect the Rain Barrel Diverter Kit

Follow your diverter kit’s instructions, using a hacksaw to cut a spot in your downspout to insert your diverter. You want the diverter just above the rain barrels but where you can still reach it.

Set up the diverter to drain into your first barrel. Open all of the hose outlets on your barrels, except for the watering hose outlet. This allows the water to spread out among all five barrels.

Rain barrel diverter kit
Rain barrel diverter kit on gutter

12. Attach a Hose and Get to Watering!

Attach a hose to the additional hose outlet on your first barrel. When you’re ready to water, open the hose outlet. Then close it when you’re done to save your remaining water.

The fuller your barrels get, the better pressure you’ll have for watering your garden. Pretty soon you’ll be watering flowers all over the place.

Rain Barrel Tips

  • Each hose outlet has a shutoff. This is helpful for troubleshooting. If you ever do have a leak, you can close all of the hose outlets to figure out which barrel is leaking, while saving the water in the other barrels. Then you can replace parts as needed to fix the leak.
  • Check if your water company offers a discount or account credit for rain barrel use. In Portland, we get 75% off our onsite stormwater charge, which adds up to about $100 in savings per year.
  • Remember to disconnect your diverter and drain your barrels before the weather gets frosty. If they have water in them, the parts can expand or break.
  • …But then don’t forget to reconnect your diverter in the spring, as soon as the frost is gone but you still have some good rainy months left in the season.

So there it is, all the info and links you need to build your own rain barrel system. I hope you’ll go for it. When you do, I would love to see photos!

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2 thoughts on “DIY Rain Barrel System: The Complete Guide”

  1. Oregon is the perfect place for the rain barrel system and you guys have it pegged right on! You’ve done an amazing job building it and putting it to use!! I am sure anyone looking to use this system will find your instructions very helpful and informative!


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