Harvest Rainwater with a Rain Barrel
First published on garden.org on July 17, 2008, by Suzanne DeJohn
With much of our region experiencing serious drought and some of the hottest
weather still ahead of us, now is the time to look for more ways to conserve
water in your landscape.
We've had some dramatic thunderstorms roll through our area, with the rain coming
fast and furious for just a short time. We might get a half inch of rain in a
half hour, but that doesn't provide as much water for our garden as rain coming
in gentle, all-day showers. Downpours like the ones we've had hammer plants,
tear foliage, and pack down the soil. Water runs off instead of soaking in, creating
gullies and washing away topsoil. It's better than no rain at all, but only barely.
That is, unless you have a way to capture and store some of that water for future
According to one source, an inch of rain yields more than 700 gallons of water
running off the roof of a typical house. Rather than letting that water run off
into storm drains, carrying pollutants with it, why not harvest some of it to
use in the garden? It's easy with a rain barrel.
Rain Barrel Basics
The simplest rain barrel is a big trash can placed underneath the downspout of
your gutter. But the features on purchased rain barrels make them safer and easier
to use. Or, construct your own from food-grade plastic barrels. Here are some
things to keep in mind:
-- A tight-fitting cover will keep out debris and prevent mosquitoes from laying
eggs in the standing water. It will also prevent curious children and animals
from getting inside.
-- Use screens over gutters to prevent leaves and other large debris from entering
-- Barrels made from dark materials block sunlight and discourage the growth
-- Although you can dip a watering can into the barrel, a spigot makes filling
it much easier. Attach a hose to the spigot to deliver the water right to your
-- Raising the barrel up on a stack of pallets or cinder blocks will make it
easier to get your watering can under the spigot. It will also increase the water
pressure flowing to a gravity-fed hose or irrigation system.
-- Water is heavy! A full 55-gallon barrel weighs more than 400 pounds. Make
sure the support under your barrel is sturdy and level.
-- A heavy downpour will quickly fill a 55-gallon barrel, so attach an overflow
system to direct excess water away from your foundation.
Don't drink water that's been captured in a rain barrel. Contaminants from bird
droppings to asphalt shingle debris are carried into the barrel with the water
as it drains from the roof. Some roofing materials are treated with preservatives
and algicides, too. In fact, some experts suggest that water collected from rooftops
is unsuitable for use on edibles. Others dispute these risks, saying that washing
produce is all that's needed to make sure it's safe.
To encourage homeowners to conserve water, some municipalities sell rain barrels
at reduced cost. Start by contacting your state's conservation district; the
National Association of Conservation Districts provides contact information: http://www.nacdnet.org/about/districts/directory/index.phtml