If you've wondered whether rain barrels can help your household utility budget as well as the environment, here are some numbers that might answer that question.

For every thousand square feet of roof space, one inch of rain will produce 620 gallons of runoff, according to expert Mike Ruck. Rainwater harvesting is a topic that has intrigued Ruck since the mid-1990s when he and his wife, Lynn, received a rain barrel that his grandfather made for his grandmother in Texas in the 1960s. The gift spurred a life-changing interest in rainwater harvesting for the Rucks that led them to co-found Rain Water Solutions. The company, located in Raleigh, North Carolina, works with homeowners, local and state agencies, municipalities and public and private institutions to develop custom rainwater catchment solutions.

"The pitches and angles of your roof, don't matter," said Ruck, when discussing the amount of rainwater that falls from a roof. "Here, in Raleigh, we can count on an average of three inches of rain a month. That's 1,800 gallons of rainwater for every thousand feet of roof!" While rainwater collection potential in the Raleigh area is greater than might be possible in many parts of the country, 95 percent of homes in the United States would benefit from having a rain barrel, Ruck added.

But, if you're going to set one up, you need to do it right. "It's important for people to have a good experience with rain barrels," he said. "If the water in the barrel goes bad, it will smell, and people will stop using their rain barrels."To keep that from happening, Ruck suggests five easy rules in setting up and maintaining a rain barrel.

Darker colored barrels will prevent the absorption of UV rays that can lead to the formation of algae. Alison Hancock/Shutterstock

1. Make sure the rain barrel is a dark color. Light-colored rain barrels let in the sun's ultraviolet rays, which will cause algae to form in the water and the water to take on the smell of rotten eggs. Clear-colored drums that are available from some sources can be painted.

2. Screen the inlet. The mesh on the screen needs to be small enough to keep mosquitoes from getting to the water and breeding.

3. Choose a rain barrel with a removable lid. This will make it easy to periodically clean the interior of the rain barrel. Occasional simple maintenance, generally once a year, will also help prevent algae from forming. This is especially important in the South after pollen season.

4. Ensure the rain barrel has an adequate overflow port. Because rain barrels are typically attached to a downspout beside a house, overflows potentially can cause serious problems.

5. Install an outlet as close to the bottom of the rain barrel as possible. This will help in draining all of the water from the barrel.

The Rucks created a YouTube video that shows how to set up their popular Ivy rain barrel; the principals are the same for installing other types you may choose.

Ruck says people often make two common mistakes when setting up a rain barrel. One is that they place the rain barrel in a location that doesn't have easy access to the plants they want to water. Another is that they place the barrel on an unstable base. "When full of water," Ruck said, "a 55-gallon rain barrel will weigh 400 pounds." Even with a stable base, he recommends strapping the barrel to the side of the house, especially in earthquake-prone areas, such as parts of California. Other mistakes, he said, include using light-colored barrels and failing to properly screen openings.

Another important consideration, Ruck added, is to know who previously owned the 55-gallon drum you want to use as a rain barrel and what they used it for. Soft drink companies, for instance, will sometimes donate drums that have been used to ship syrup to conservation-minded groups. These can make great rain barrels, Ruck said, as long as they are painted or covered to minimize UV light entering the barrel. However, he added, if a drum has been used by a chemical manufacturer, then it might not make such a good choice for a residential rain barrel. A rain barrel specifically designed and manufactured to be a rain barrel alleviates this concern.

Harvest water locally

When purchasing a rain barrel, look for one locally, he advised. Because they are bulky, it can be prohibitively expensive to ship individual rain barrels, Ruck said. He helps consumers avoid high shipping costs by partnering with municipalities in local rainwater harvesting programs. He designed his rain barrels so that they can be stacked inside each other, which allows 33 to fit on a single pallet. The stacking capability reduces shipping costs to municipalities that participate in his Rain Water Solutions program.

Municipalities that work with Ruck include Nashville and Knoxville in Tennessee; Ventura and San Francisco in California; Houston and Fort Worth in Texas; Mamaroneck, New York; Salt Lake City, Utah; and Bellingham, Washington. He would like to work with municipalities in Colorado and is closely watching a bill before the state legislature that would make rainwater collecting legal in the state.

Ruck suggests visiting the website of the American Rainwater Catchment Systems Association to learn more about rainwater harvesting. ARCSA's mission is to promote sustainable rainwater harvesting practices to help solve potable, non-potable, stormwater and energy challenges throughout the world. Resource guides and other information on the site are useful to anyone interested in collecting rainwater, whether you're a professional in the industry or a backyard amateur just trying to do your part to help the environment and to reduce your household budget.