April showers bring May flowers. They also bring valuable rainwater to harvest and temporarily store for later use in watering plants. Old fashioned rain harvesting methods, like rain barrels, have made a comeback for this purpose. The photo above is Double rain barrels at Hastings NE Prairie Loft.

Rain barrels are limited in the amount of rainwater harvested, but can be a first step to rainwater harvesting. They are homemade or purchased commercially. If making your own, start with a food grade barrel or one in which a nontoxic material was stored.  Our publication on how to make a rain barrel is available at extensionpubs.unl.edu or https://extensionpubs.unl.edu/publication/ec2001/2014/pdf/view/ec2001-2014.pdf

Rain barrels are typically 50 to 100 gallon size. From a 1000 square foot roof, it is estimated up to 125 gallons of water will flow from one downspout during a one-inch rain. The larger the storage barrel, the better; and overflow must be planned for.

For overflow, rain barrels have an opening near the top so excess water flows out once the barrel is full. PVC pipe or flexible hosing is typically connected to the opening to direct water away from building foundations to a lawn, shrub border, or rain garden for capturing and infiltrating more rainwater. 

Spigots are attached near the bottom for attaching a hose to access the water. Placing rain barrels on a sturdy platform, like cinder blocks, provides a slight increase in pressure and makes it easier to hook a hose to the spigot. Firmly attach containers to buildings for safety. Rain barrels need to be covered and have fine mesh screens to keep children, pets, wildlife and mosquitoes out.

Rainwater is quality water for irrigating plants. It is naturally soft, oxygenated and more acidic than tap water. It is free of chlorine, fluorine and salts. It is highly recommended for irrigating ornamental plants like flowers, grasses, trees, and shrubs. 

Most rainwater is collected from rooftops. As it flows over a roof it picks up bacteria from bird or squirrel droppings or chemicals leached from roofing materials and gutters. While collected rainwater might be used for watering edible plants, extra precautions must be taken such avoiding contact with edible plant parts and using food safety practices. Ideally, only use it for watering ornamentals. 

After handling rain barrel water or cleaning barrels, wash your hands. Untreated water should not be used for drinking by people or pets, to fill children’s swimming pools, for hair washing, bathing, or to wash harvested produce. 

A common issue with rain barrels is algae growth inside the barrel. To reduce this, limit nutrient build-up in the barrel by decreasing the amount of sediment and plant debris entering the barrel. These are sources of nutrients like phosphorous and nitrogen that promote algae. 

Clean roof gutters at least annually. If hosing out the roof gutter, remove the rain barrel before cleaning. Consider installing gutter screens along with using screens/filters before the rain barrel inlet. Clean the barrel at least once a year to remove sediment. Use dark-colored, painted, or opaque barrels to limit light and place rain barrels in a shady location if possible. 

For information on rain barrel use, see our NebGuide at https://extensionpubs.unl.edu/publication/g2220/2014/html/view.