Drive through downtown Oak Park, down Lake Street or Harlem Avenue, and you see something unexpected on the side of the road - 100 elaborately painted kegs meant to collect rain instead of trash.

These ornately styled 55-gallon rain barrels are on display this summer as part of an effort by the League of Women Voters of Oak Park/River Forest to pique neighborly interest in sensible water management.

Conservation groups across the country widely hail residential rain barrels. They view the plastic drums that collect and store rainwater from roof gutters as common-sense devices to help control runoff during heavy rains and reduce water use. A hose spigot at the bottom allows people to later use that water to wash their car or water their lawn.

As functional as rain barrels are, they have become equally important educational tools to introduce people to the delicate water cycle that begins before the faucet and continues after the flush.

“Rain barrels provide an opening to educate people about managing storm water and being a good environmental citizen,” said Debra Shore, a commissioner of the Metropolitan Water Reclamation District, which manages and treats sewage and runoff for most of Cook County. “That’s the principal benefit of them for our agency.”

In Oak Park, resident Amy Little can’t claim all the credit for the artsy rain barrel program but she can take some.

She is the environmental committee chair for the League of Women Voters of Oak Park/River Forest and point person for turning the otherwise unexceptional drums into flashy eco-sirens ensnaring the attention of passers-by.

The league bought the barrels and then sold them to various groups, residents and churches, who either painted them themselves or hired artists to do so.

Little lifted the idea from the suburbs of Geneva and Aurora, which organized similar efforts. But believing that the barrels could do more than just look pretty she carried the idea one step further.

“We added tags to all of the barrels with 40 water-saving tips,” Little said. “They needed to be about more than just art and actually educate people about the environment.” Tips advise people to turn on the shower only once you are in it and to turn the water off while you brush your teeth.    

While rain barrels help at least marginally to relieve the strain on city sewer systems during heavy rains, they also keep perfectly good water from going through the expensive and energy-intensive treatment process that all sewage requires. In Chicago and 50 of the older suburbs, stormwater drains into combined storm and sanitary sewers and must be treated too.

“The bottom line is that [the barrels] put water back into the Lake Michigan watershed instead of the sewer,” Little said.

Any rainwater that enters the sewer system gets treated and ultimately flushed downstream to the south. But in parts of Cook County, rainwater that soaks into the ground makes its way back to Lake Michigan, the source of the entire region’s drinking water.

“To the extent that they keep rainwater from being contaminated,” said Shore, “then that means there’s a little bit less water going to the treatment plants, which helps reduce energy costs.”

Since the barrels have been on display on street corners throughout Oak Park, sales at local stores have skyrocketed.

Maria Onesto Moran owns Green Home Experts in Oak Park, a retail boutique that sells eco-friendly building and home supplies. Onesto Moran said she sells four kinds of rain barrels, from smaller plastic ones (formerly food containers) to oak wine keg barrels. She can’t keep enough in stock, she said.

“They’re hot cakes,” Onesto Moran said. “A couple of years ago, they were considered kind of weird, something only hippies had, and now they’re much more the norm.”

In its first year, Green Home Experts sold fewer than 100 barrels, Onesto Moran said. Last year that number tripled. This year Onesto Moran expects sales to at least double last year’s total.

“I would say in springtime, April to June, they are by far the most popular seller in the entire store,” Onesto Moran said.

Isaac Sinnott, an Oak Park/Lake Forest high school student, has developed a booming business manufacturing and selling rain barrels out of his parents’ backyard and online at his Web site letitrainbarrels.com.

The Metropolitan Water Reclamation District buys rain barrels wholesale for $80 each but sells them for $40, both to Cook County residents and to municipalities, who can turn around and sell them, as well, so long as it’s not for profit.

Last year the district ordered 1,000 barrels and quickly sold out. In the last 10 months, the district has sold 2,500 rain barrels and just ordered several hundred more, according to spokeswoman Jill Horist.

So far in 2009, the villages of Evergreen Park, Lincolnwood, Homewood, Glenview, and Berwyn all have purchased the maximum of 40 barrels offered by the district, and Palos Heights, Berwyn and Buffalo Grove have bought some, as well.

Commissioner Shore and her staff plotted data on where rain barrels are being sold and found a surprisingly wide variety of locations across the county.

“They make a lot of sense, and that’s why I think people are embracing them,” Shore said. “It’s bubbling up through the culture, and not just the wealthy, garden-rich communities.”

Though their recent popularity appears to be a new phenomenon, rain barrels are an old idea. Farms especially have used rain barrels for decades and, during the Great Depression, nearly every rural home had them.

“We just do the easiest thing now,” Little said. “It’s easier to turn on the sprinkler. People have gotten away from Depression-era things, and we just don’t do them anymore.”

Aside from their sensibility, Shore credits a growing awareness of environmental issues, both of water quality and supply, for the success of rain barrels and said she hopes they will lead people to explore an entire suite of successful water-management techniques, such as permeable pavements, rain gardens and better discipline about turning off the faucet.

Yet for all their sensibility, rain barrels aren’t perfect.

“They do require a lot of manpower,” said Little. “People expect it to flow like a hose. It’s not a hose – it’s really a watering can. They’re not for the faint of heart.”

The barrels must be connected to a gutter’s downspout, which can take some installation know-how, and, oftentimes, they can’t be connected at apartment buildings where gutters feed directly into the sewage system.

Lincoln Park resident Cynthia Raskin got interested in rain barrels after seeing them in outlying areas but rarely inside the city.

“To be honest,” Raskin said, “Nobody where I live has ever heard of rain barrels or knows what they look like.”

Raskin, who owns a public relations firm, now serves as the volunteer coordinator for Chicago's non-profit Recycle the Raindrops, which hires artists to paint rain barrels to distribute around the city.

Recycle the Raindrops is working with Chicago’s Department of Water Management to get the barrels placed at tourist sites, in front of libraries, in department store windows and at garden shows.

“We’re not in dire circumstances right now,” Raskin said, “but we will be. Chicago is one huge straw drinking up Lake Michigan.”

Raskin acknowledges that rain barrels aren’t as easy to install in the city as they are in the suburbs, but maintains that more can be done.

“There are plenty of bungalows, plenty of houses in the city,” Raskin said. “I have friends who attached two to their garage roof.”

Neither the water reclamation district nor the City of Chicago knows exactly how many rain barrels there are in the area, so it’s tough to quantify their hydrological impact.

It’s unlikely that rain barrels alone would prevent the district from needing to release untreated rainwater into Lake Michigan to prevent flooding once the sewage system gets overwhelmed during heavy rains, as it did on June 20 and four other times since last September.

Nonetheless, Shore said she is in the earliest stages of developing a pilot project to target a flood-prone community with rain barrels and other water management techniques to get a more accurate reading of what kind of impact they might have as a whole on a community. But that plan is a long way off.

In the meantime, rain barrels will continue to contribute, both as public art and as backyard watering cans, to managing rainwater and curbing tap-water use. And even if they can’t quite quantify their impact exactly, water conservationists know one thing.

“Sure, a couple of 55-gallon barrels is not significant,” Horist said. “But just do the math: the more rain barrels, the better.”