How to Buy, Install and Use a Rain Barrel

A rain barrel is a container that collects runoff from your home's gutter system, connecting to the downspout with a rain diverter or fitting under a modified downspout. A spigot or hose connector lets you drain the water for use around your landscape. Rainwater harvesting provides an alternative to using municipal water or well water for irrigation. Plants benefit from water that's free of the chemicals and minerals in tap water. Rain barrels can reduce the volume of runoff entering the storm sewer, keeping pesticides, fertilizer and other chemicals out of nearby bodies of water. Collecting rainwater for later use also keeps it from entering your foundation, crawlspace or basement. Some cities offer financial incentives for using rainwater for irrigation as a supplement to municipal water.

Plan to install the rainwater barrel at a downspout where you need the water. A rain barrel supplies low-pressure water, and the flow rate decreases as the barrel empties. You can improve the flow rate by elevating the barrel. Some barrels come with a pump to increase water pressure. The increased flow can supply low-pressure drip irrigation, but sprinklers and hose-end sprayers don't work with a rain barrel. Your other alternatives for dispensing the water are a garden hose, soaker hose or watering can.

Estimate how much rainwater you'll capture. Collection rates vary depending on the slope and size of the roof. For estimation purposes, a 1-inch rainfall can yield a little more than half a gallon for each square foot of roof. The downspout you direct to the rain barrel channels water from only one section of your roof, so use that section to calculate the amount of water you can collect.

Plan for overflow. A 1-inch rainfall on 100 square feet of roof will generate about 60 gallons of water. If the barrel overflows, the excess water needs to flow away from your home's foundation. Some barrels include a hose that drains the overflow. Others use a basic overflow outlet. Your barrel may have a debris screen and a built-in groove to direct excess water. You may also be able to link barrels to collect the overflow.

Select an overall size and capacity based on where you plan to set up the rain barrel kit and how much water you expect to collect. Choose a color and design that fits your landscape and home. There are also a few features you can look for:

• A debris screen keeps leaves, animals and insects (including mosquitoes) out of the barrel.
• A flat-back barrel fits close to your home, so the barrel is farther out of the way. Your downspout may require less modification to fit a barrel with a flat back.
• An opening lid lets you dip a watering can into the barrel for quick filling. A closed top or latching lid helps keep children and animals out. The tops of some rain barrels function as planters.
• The water outlet is either a spigot or a hose connection. One outlet is located at the bottom of the barrel; some barrels have an additional higher outlet for filling a watering can.
• A collapsible design makes storage easier.
  

Before you install or use a rain barrel, make sure your gutters and downspouts are clear and functioning. See Gutter Cleaning and Repair for information on maintaining your gutters. The process for setting up your rain barrel will vary by model, so follow the manufacturer's instructions. Here are the basic steps.

The water you collect in a rain barrel is untreated. The absence of chlorine and other chemicals is good for plants but humans and pets shouldn't consume it, and you shouldn't use it for cooking, washing your hands or washing food. If you use the water to irrigate herb, vegetable or fruit plants, apply it to the soil, not the plants. Wash vegetables and fruit in tap water before eating or cooking them. Use soap and warm tap water to wash any parts of your body that touch the collected water.

Make sure your rain barrel doesn't cause mosquito problems. A debris screen keeps mosquitoes from entering the main water inlet, but you can caulk any gaps that might allow them to enter. Mosquitoes may still be able to enter through overflow outlets, so eggs or larvae may be washed into the barrel from your gutters. Use the water promptly to help prevent eggs from developing into mosquitoes. You can add anti-larval tablets containing Bacillus thuringiensis to the water to kill mosquito larvae.

Use the rainwater within a week or two of collection to help prevent odors from stagnant water or algae growth. If possible, use the collected water before the next rain. When you're not collecting rainwater, leave the spigot on the barrel open. Place a splash block under it or connect a hose to prevent erosion and to keep water from entering your home's foundation. Remove the barrel and reconfigure the downspout to handle runoff if you don't plan to use the barrel for several days or longer.

Secure the barrel to keep it from tipping over. Some manufacturers recommend always leaving some water in the barrel to keep it in place. Inspect it regularly for damage or leaks. Clear away anything blocking the debris screen. Rinse out the barrel as needed to clean out sediment or debris that passed through the debris screen.

Drain and disconnect the barrel before freezing weather arrives. Set your gutter downspout so it'll handle runoff, either by reinstalling the portion you removed or setting a diverter to downspout use. Rinse the barrel out before storing it.