Build a Rain Barrel

This tutorial describes how to set up a “closed” rain barrel system. I am currently using 3 full-sized (55 gallon) closed rain barrels for my garden watering needs and also an open half-sized rain barrel for distribution of local water for irrigation of a hard-to-reach garden.

To Make or Buy a Rain Barrel?

Before you start, I will say this: It is far easier to purchase a pre-made barrel, but they cost between $50 – $150 each and most are open systems. If you prefer to purchase a complete rain barrel kit, there are a number of them available and many will come with full instructions for setup.

For my purposes, I wanted 3 barrels which would serve two gardens and fill up a small pool. Given that I was not sold on whether they would even work, I was unprepared for this kind of monetary outlay. So for less money and a little bit of skill, you can make one pretty easily. Again with a closed system, you don’t have to worry as much about debris or controlling mosquitoes.

Materials you will need

Materials you will need, click for larger view

The Barrel
  • 55 Gallon Food-Grade Barrel- used container companies for buying a rain barrel
  • Downspout diverter- various types exist and can be purchased online
  • Power drill
  • 3/4 spade drill bit (for the spigot)
  • 7/8 spade drill bit (for the caps)
  • Hair Dryer
  • Plumber’s tape
  • 5/8 to 1/2 inch spigot OR 5/8 to 1/2 inch brass hose adapter
  • Optional: Valspar* or Krylon* Plastic Paint ($5- my barrels were white, I painted them forest green to reduce algae growth
  • Optional: 5/8 to 3/4 inch male hose coupler (connects the downspout and completes the closed loop)- $1.00 (available at a hardware store)
  • Optional: Random lengths of hose (the kit comes with a white hose, but I used a garden hose so that I could connect the coupler)
  • Optional: 1/2 inch Y Adapter for hose (I use this for connecting one downspout to 2 barrels, or to hook up 2 hoses to the barrel for output)


This is what the barrels look like after they are painted with the plastic spray paint.

Using the 3/4 inch spade drill bit, drill a hole near the bottom of the drum.Tip: Practice on another piece of plastic so you can test the fit of the spigot. Keep a firm but gentle pressure, and take your time so that the bit doesn’t rip the plastic, instead of cutting a nice uniform hole.
This is what the hole should look like when you are done.
Heat up the plastic so you can create the threads in the plastic. Using a hair dryer, heat up the plastic, but do not get too close. You are just trying to get it nice and flexible.
With the plastic heated up, now screw in the plastic or brass spigot (depending on which one you chose). Screw the spigot with straight and even pressure so that the threads form in the plastic. Once you do this, the plastic should cool and allow you to unscrew it without changing the threads.
Unscrew the spigot and then wrap plumber’s tape on the threads. This will create a nice tight fit and eliminate leaks. Make sure to wrap it in a clockwise direction, so that the tape will not unwind when you screw the spigot in.
Screw the spigot in again slowly.
One of the two barrel bung caps has threads on the inside of the cap (in the center). These threads allow you to punch a hole through the cap and then connect a hose to it. The cap however doesn’t have a hole to start with, so it must be drilled. Drilling a hole will not affect the threads, but will allow you to now create the closed system (less mosquito issues and creates the back-pressure overflow that will run excess water back up to the downspout).
Using the drill and the 7/8 inch spade drill bit, center and drill the hole to “punch it out” of the cap.
This is what the cap looks like after drilling the hole.

The End Result

This is one of the WaterSavers diverter hooked up with its own hose, to the coupler, screwed directly to the cap to create the closed system. I will not provide details on the downspout installation, because each downspout diverter has its own installation instructions.

This picture is small, but you see the “Y” split from the Watersaver to the hoses and then the coupler connecting directly to two barrels to create the closed system. From the bottom spigot, I run another hose underground, and then connect it to a soaker hose for “drip irrigation”. This saves a ton of water and the plants love it because it doesn’t contain any additional chemicals or chlorine.

How to dispense your rainwater

This is definitely the biggest challenge for me, mainly because one of my gardens is uphill from the barrel. The other garden is below the barrel, and it works great. When you are setting up your barrels, place them on cinder blocks to get the barrel as high as you can. I hook up the low-flow soaker hoses. Be sure to remove the little filter inside it because that filter is only to reduce the pressure from a regular hose. The barrels have lower pressure, so that filter is not needed. I have a hand-pump sprayer (works like a pump squirt gun). It gives me plenty of concentrated pressure when I need to clean something. To move the water to the upper garden, I have a rotary pump, which connects the barrel to the half-barrel in the upper garden. I pump about 5 gallons into the upper barrel, and then I release the spigot and it runs through the soaker hoses. I am working on a drawing that will show what the entire system looks like.

Rain Barrel Resources

The Barrels *

Complete Rain Collection Kits *

Hand Pumps for water *

* Note: This information and products described here are intended for informational purposes only and are not product endorsements for purchase. The BRWC/FOB is not associated with the manufacturers or online retailors listed and recommends that all consumers do their own research before purchasing a product.

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