URBANA, Ill.—Residential rain barrel usage can help with storm water management and water conservation. Getting people to adopt this relatively new green technology in their own back yards is the challenge.
A recent study conducted by University of Illinois Environmental Economist Amy Ando and her graduate student Luiz Freitas examined the outcomes of a citywide rain barrel campaign over the past few years in Chicago to discover who is most likely to buy a rain barrel and why.
Ando said the city of Chicago was interested in increasing rain barrel usage for two main reasons.
They thought that rain barrels could help with storm water management—if you have an empty rain barrel, it’ll capture about the first 50 gallons of rainfall on your property, and if you have enough of them, that could add up to a significant amount of storm water management across the city. But almost as important, the city was interested in having people use the collected water to water their plants, wash the dog, wash their car, reducing demand from the municipal water supply.
The data analyzed in the study was obtained from the Chicago Department of Environment and the Department of Water Management, Census data, and Chicago’s municipal service request system 3-1-1.
Chicago uses a service called 3-1-1 to track complaints about street lights that are out, potholes in the road, water in your basement, ponding in the street—little problems like that. They gave us all of the data about flooding so we were able to map out which parts of the city had the most flooding to see if that would correlate with how many rain barrels were purchased,
The study found strong links between rain barrel adoption and both income and proximity to the distribution sites. Ando also said:
Ideology seems to matter. People who voted for the Green Party in the 2006 gubernatorial election were more likely to purchase a rain barrel.
Ando explained that the study used a continuous variable for income.
So we can say that wealthier people are more likely to buy rain barrels. Propensity to buy a barrel increases with income, but then it levels off.
Rain barrels were less widely purchased in areas of the city that have a high density of high-rise buildings. Ando attributes this to the fact that there isn’t a good place to install a rain barrel near a high rise, and there aren’t private gardens near the buildings where residents could use the rain water that’s collected, reducing the private incentive to buy a barrel.
Ando describes the use of rain barrels in economist’s terms as having a private good and a public good.
If you have a rain barrel, you get water that’s not treated with chemicals to water your plants with, and some avid gardeners like that, so that’s the private good part of it,
The public good is that by having a rain barrel, you’re doing your part to reduce storm water runoff. And in the theory of the consumption of that kind of mixed good, it’s possible for the state of the public good—the amount of flooding in this case—to increase, decrease or not affect private purchases of the good.
The study also noted a small correlation between the places rain barrels were purchased and the locations of Chicago’s Green Alleys. The Green Alley program is somewhat linked to the 3-1-1 complaints.
Sometimes when an alleyway needs to be fixed up, if they get a lot of complaints about it flooding, having potholes, instead of restoring it as a regular paved-over alleyway, the Department of Transportation fixes it up using new green infrastructure. They use permeable pavers or porous concrete with bioswales along the side, and so the whole thing is designed to let water infiltrate and reduce runoff,
They view it as a good investment because you don’t get flooding there, and the design reduces storm water runoff.
Whenever a Green Alley is installed, the city provided residents with information about green technology, Ando said:
They do a little localized education campaign. They tell people along the alley about green infrastructure and how things like rain gardens, rain barrels, and permeable concrete or porous pavers can reduce storm water runoff and flooding and increase groundwater infiltration.
Ando said they were interested in if there was any sign the people near Green Alleys were more willing to go buy a rain barrel.
Some of the results tell us yes, but it’s a faint signal in the data because there aren’t many Green Alleys. We have a lot of census tracts that don’t have Green Alleys and a very small number that do. But there’s at least limited evidence that people are a little bit more likely to buy rain barrels if they live near a Green Alley. We think it’s most likely because of the education campaign, but you would need to do a survey to get at the causality, the reason for that correlation.
One question Ando hopes to find an answer for in the future is whether it’s possible to get more value in terms of storm water management from rain barrels being in one part of the city than the other.
The city is trying to identify areas where having more green infrastructure would be more beneficial,
So, if it’s true that there are some parts of the city where a rain barrel here is more useful for storm water management than a rain barrel there, then you might want to do a targeted campaign and make it particularly convenient for people in some areas to adopt rain barrels.
Ando said the city of Chicago is thinking about changing its rain barrel campaign strategies.
Instead of selling the rain barrels, they may just let retailers handle that while the city concentrates on the business of teaching people how to use them, how to set them up, how to use them effectively.
Funding for this project came from the Adaptive Environmental Sensing and Information Systems Initiative at the University of Illinois and from the Cooperative State Research, Education and Extension Service of the U.S. Department of Agriculture. Ando is a professor in the Department of Agricultural and Consumer Economics in the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois.