Rain Collection for Lawns and Gardens

rain water collection systemsCollecting water in “catchment” systems such as a rain barrel is an ancient practice dating back three-thousand years. Catchment systems are quite common in remote and rural areas, where water can be a very precious commodity.

For homeowners interested in water management and conservation, a rain barrel makes good sense. Rain barrels typically collect water running off a roof by way of a gutter and a shortened downspout. Catching storm water diverts it from storm drains and lakes and rivers, before it can pick up pesticides and other pollutants along the way.

In many countries, filtered and strained rain water is collected for a variety of uses other than plant watering, but air pollution still makes it inappropriate for drinking. Experts in the U.S. caution against using roof runoff for watering edible plants, at least without purification.

While a full rain barrel looks like it contains a large volume of water, it’s actually good for just nine minutes of watering with a garden hose. While this may not make it a dependable primary source of lawn and garden irrigation, it is a handy alternative water source.

Exactly what’s in rain water?

Rain water is classified as “soft water,” meaning that it contains low concentrations of minerals such as calcium and magnesium. Unlike tap water, it contains no chlorine, fluorine, or other chemicals, making it an excellent choice for thirsty yards and flower gardens.

Contaminants in found in rain barrel water tend to be those that wash off the roof and gutter, including droppings from animals such as birds, lizards and mice. Dead animals and insects may also find their way into gutters or the barrel itself. Rain water may also contain a range of microorganisms, but they are not considered a significant risk to healthy gardeners.

Good rain barrel designs include fine mesh screening at the intake area to prevent these contaminants, mosquitos and other creatures from entering.

Maintaining a rain barrel

  • Position the barrel on a sturdy base high enough to fit a watering can underneath.
  • Clean gutters regularly. This keeps debris from ending up in the rain barrel. Trim low-hanging vegetation that could also find its way into the gutters.
  • Use the water within 30 days. If algae develop, add a tablespoon of vinegar.
  • Repair small leaks with aquarium sealant.
  • Follow recommendations for winterizing (emptying) rain barrels in cold climates.

More information about rain barrels

Many municipalities offer workshops, subsidies, or buying programs for rain barrels. For the do-it-yourselfer, assembling a rain barrel is simple and inexpensive (about $55.). There are many sources of 55-gallon drums and the necessary hardware.

rain barrel

The EPA has a rain barrel building handout available here:

Maryland’s Montgomery County’s Department of Environmental Protection offers rain barrel and rebate information here:

Maryland’s Prince George’s County Department of the Environment has a helpful fact sheet with additional web links located here:

Virginia’s Arlington County offers rain barrel making workshops and barrels for sale here:

Virginia’s Fairfax County Soil and Water Conservation District rain barrel making workshops and barrels for sale here:

Washington D.C. offers a rain barrel rebate program for 2018:

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