How to Build a Rain Barrel

A rain barrel outside a garage.
What You'll Need
Measuring Tape/Ruler
Safety goggles and gloves
Container (32-gallon garbage can is about $15)
Rain barrel kit ($20-40 not all hardware stores carry them)
Or Hacksaw
Downspout diverter ($10)
1-1/4" Hole Saw bit for drill ($8)
Two threaded rubber gaskets 1-1/4" ($9)
Two spigots ($10)
Overflow hose ($10)

On average, more than half of an American’s household water usage goes toward landscaping. This can be expensive and is bad for the environment; those who live in areas prone to drought are all too familiar with water restrictions and what a precious resource it is. The inexpensive and environmentally friendly solution to sourcing water for landscaping is to make a rain barrel (which is not meant to house drinking water). Be sure to check you local laws and regulations first as some municipalities do have restrictions.

Step 1 – Pick Your System

The kit supplies.

You can have a freestanding container that will capture the water as it comes down or you can connect it to a downspout. A freestanding container is going to be the easiest, but you are more likely to create a breeding haven for mosquitoes this way. Keep in mind that it is possible for either option to attract pesky critters.

There are a few options to help alleviate your mosquito dilemma should it occur. You can plant flowers around the area that will repel the bugs, put goldfish or minnows in the rain barrel, or drop in a repellent specifically made for these systems. The best part is that the fish will live off of the eggs (no need to feed!) and goldfish will survive year-round in certain climates.

There are a plethora of system designs you have to choose from if you are connecting to a downspout. The easiest option is to purchase a kit, which come with practically everything you need minus the container. This system also makes it easy to attach a second container and overflow will automatically be directed through the downspout.

One thing to note is that if there is any kind of wiring in your downspout, you can injure yourself or do serious damage to your house.

Step 2 – The Container

A trash can laying on a tile floor.

The kit works with containers that are wooden and plastic. They're not recommended for use with metal. Regardless of your choice, the container should be free of chemicals, which is especially true if you are planning to use the water for anything edible. If you're getting a large drum, you want one that is food-grade. You can use one that is sealed or that has a lid with a latch. Your cheapest option will likely be a trash can.

Step 3 – Where to Put It

An elevated rain barrel.

Pick an area that is level and can support the weight of a full container. If the area is not level, you can grade it using a rake or shovel. Your system will be less efficient if it isn't level, or might not function at all. The kit will require that it be placed between 6” and 28” from the source.

It's a good idea to use an elevated surface such as a platform, which is something you can make yourself. This rain barrel in the photos is sitting on top of pavers stacked two high. This is also a way you can level out where your container will be sitting. The benefits of having it higher up are that hooking up your hose will be easier and there will be more water pressure.

Step 4 – Line it all Up

Regardless of how you will be diverting the water from the downspout, mark where the top of your container will be on it after elevation (this is where you will be placing the diverter for a sealed bin). If you're going to be using something that will go into the top of your bin, you will also make a mark above that (the distance will depend on the vertical size of your connector). This is where you will cut and attach your diverter, which can be done using a hacksaw.

A ruler measuring a downspout.

You will also make a mark 3” in the center below your mark where the top is if you are using the kit and a basin that is not sealed. Then, make a mark 3’ below the top of your bin (without the lid on). The rain barrel kit has two options. Option A is for those will be using a hose and option B is for those who will be using a watering can. Option A requires only one additional mark, which is 3” above the base of your drum. For option B you will make an additional mark 12” up from the bottom.

A trash can with a 3-inch mark on it.

If the water is going directly into the basin, you will need to make a mark 3” from the top of it for overflow.

Step 5 – Make Your Holes and Insert Seals

Hole in downspout.

You will be using a hole saw kit and a drill for this part, which comes in the kit. The places you marked on your rain barrel will serve as the center of where you will be making the holes and aligning the drill bit that is in the middle of the saw. The medium saw is used for the water inlet if you are using the kit, and insert the fill hose seal by pinching the top. The other hole(s) will be made with the small saw and will require the threaded rubber seal. These seals will be easier to install with a lubricant such as a little lotion or oil.

A screwdriver attaching a piece of hardware to a downspout.

When making the hole in your downspout with the large saw, it should be centered horizontally on the front if it is 3” x 2” or on the narrow side if it is 3” x 4”. Make sure not to force the drill when using the saw and that you wear safety glasses. This is where you will insert the diverter with the arrow facing up while wearing safety gloves as the metal may be sharp. You cannot twist it once it is in, so ensure it's straight and properly aligned. Then screw it in with the provided screws.

Step 6 – Connecting the Pieces

Rain barrel spigot.

The water fill hose is difficult to insert, so it's highly recommended that you use a lubricant. The hose will connect the diverter to the fill hose seal. The spigot will go in the top hole for option B, the bottom hole for option A, or the one for the overflow (keep a hose connected for the overflow). The drain from the kit will go in the bottom hole for option B.

If you connected your spout directly into the top of your rain barrel, seal it with silicone caulk.

Now, you have a system that will help save the environment and your wallet!