Display Posts by Category


Rain Barrels

What is a rain barrel?

A rain barrel is any wooden, plastic or terra cotta container positioned so as to capture the runoff from your roof during a rain.  A spigot near the bottom of the barrel makes using the captured water much easier.

rain barrel in situ

Why should I bother with a rain barrel?

Lawn and garden watering makes up nearly 40% of total household water use during the summer.  Rain barrels collect and store water for when its most needed during periods of drought.  Rain barrels provide a free source of “soft” water containing no chlorine, lime or calcium making it ideal for watering plants, washing cars, filling aquariums or for childrens play.

Furthermore capturing water greatly reduces the amount of water lost to stormwater run-off and the chemical pollutants from lawn fertilizers swept into our creeks and streams in a heavy rain.

How much rain water could I expect to capture?

One inch of rainfall on a 1000 square foot roof generates 623 gallons of runoff.  Assuming you have 65-gallon barrels, you could fill ten barrels during a one-inch rainfall!

How much money would that save me?

At a rate of about 1/2 cent per gallon for city water (more if you’re on sewer), you would save more than $25 during a one-inch rain! If you converted containers for maximum water collection, you would recoup more than the up-front cost during the first season of normal rainfall.

How many barrels would I need?

That will depend on how you wish to use the water and the size of your roof. If you want maximum garden use, you would calculate the amount expected from a one-inch rain and connect barrels together at each downspout for maximum collection.

Where can I get rain barrels?

Purchasable, ready-to-install barrels can be found in magazines such as Gardener Supply, at local hardware stores such as Ace, and on-line from a variety of sources, and plastic trash cans are available at all home improvement and hardware stores.  Wooden and plastic barrels and plastic trash cans must be converted.  Instructions for conversion can be found on the Master Gardener website.

What is my yard isn’t level?

Gravity is necessary to get a strong flow from your barrel.  When the yard is not level, it is easy to raise the barrels to the appropriate height using concrete blocks.  Painting the blocks is easy to create a more uniform appearance.

How do I convert a plastic barrel to a rain barrel?

The hardware and tools necessary for barrel conversion are listed on our website. With the correct tools, it’s an easy and fun job. And a Master Gardener is always available to guide you. Just call the Extension Office and ask for a referral.


Tools Needed for Rain Barrel Conversion

  • Electric Drill with boring bit
  • 3/4 inch spigot
  • Washers (2)
  • Lock Nut
  • For the overflow:
  • 1 1/2 “ 90 degree Overflow Coupling
  • Washers
  • Lock Nut
  • Plumbers Tape
  • Silicon
  • Screen Wire
  • Hack Saw
  • Tape Measure
  • Downspout Crimper
  • Larvacide Donuts
  • Concrete Blocks (for increasing gravity)

For wooden whiskey barrels which are about an inch thick, a steel nipple is necessary for both the spigot and the overflow.  Choose a boring bit to accommodate the CENTER of the nipple. (For a 3/4 inch spigot, you will probably need a 1” boring bit. Try it out on a spare piece of wood to know just how tight the fit will be. A little sanding with a round file or a Dremele might be necessary to get the best fit.)

The top of wooden barrels must be removed to install the conversion hardware.  Cutting the top out with a jigsaw leaving a 2 inch rim provides a perfect device to hold the screen wire in place.  It’s helpful to keep the pieces in the correct order as they fall from the barrel top and to mark where they go back.  Pieces must be glued back together for the rim to be useful in securing the screen wire.

Measure about 4 inches from the bottom of the barrel to drill the spigot hole.  Bits of asphalt are washed off your roof in a hard rain, and this leaves enough space for any small trash to settle.  Wooden Barrels:  Chose a wide stave (the cork stave is usually the widest and the barrel looks best with both centered in the front).

Drill the hole approximate for the size of your spigot for the size of the steel nipple on the wooden barrel.  Insert spigot with washer on the outside and begin to tighten with the washer and lock nut on the inside.  Before it’s completely tight, squeeze a bead of silicon and both sides to prevent any leakage.

Choose the side of the barrel for the overflow (important only if you will be connecting to another barrel) and follow the same procedure with the boring bit, hardware and silicon.

Now draw a circle in the plastic lid and saw the opening.  Cut a large enough circle of screen wire so that the lid holds it securely in place.  Measure 6 to 9 inches above the height of the barrel (when it is in place under the downspout) and cut the downspout with a hacksaw.  Crimp the corners and insert an elbow on the OUTSIDE of the downspout so that the flow drops into your barrel.

Attach a garden hose or soaker hose to the spigot and wait for rain. When the barrel is filled, use the larvacide donuts for extra insurance against mosquito breeding.  You will need only about a quarter of a donut per month.

Now you can take it easy during the next drought!

4 comments to Rain Barrels