Urban Flooding, Social Equity, and "Backyard" Green Infrastructure

Background and Purpose. As populations surge in urban areas, impervious surfaces increase, which creates runoff that can overwhelm aging stormwater infrastructure. Meanwhile, with climate change comes a greater chance of more frequent and severe flooding, which threatens people’s well-being and safety. Green infrastructure (GI) is an innovative way to manage urban stormwater with many social and ecologic benefits. Common types of GI include bioretention ponds, rain gardens, and rain barrels. “Backyard” GI programs work directly with residents to have small-scale GI on their property (e.g., rain gardens). Research on these programs is only recently emerging. Further, there is often an overlooked dimension of social equity. Lower- and moderate-income residents are often not reached by backyard GI, even though people in these groups are often more vulnerable to flooding or its impacts. This exploratory study aims to better understand awareness of and interest in backyard GI among an urban sample of lower- and moderate-income residents.

Methods. Data are from surveys (N=234) with lower- and moderate-income residents of an urban watershed in Knoxville, Tennessee. Participants were recruited randomly via phone and non-randomly via Facebook. Dependent variables were awareness of and interest in GI. Independent variables included prior flooding experience, climate change concerns, perceptions of local governance, neighborhood social cohesion, and several demographic characteristics. Bivariate analyses explored relationships between our dependent and independent variables.

Results. Most participants (62.9%) were unaware of the term “green infrastructure.” When specific types of GI were asked about, awareness was high for rain barrels (67.5%), but low for rain gardens (13.2%) and permeable pavement (13.4%). Having any awareness of GI, compared to none at all, was associated with being younger, having more education, renting, having flood experience, and having climate change concerns. Almost 60% of participants reported some interest in learning more about GI. Having interest in GI, compared to none at all, was associated with being younger, being married or with a partner, having more education, renting, having flood experience, and having climate change concerns. Among those with a spouse or partner, 32.1% said this person could influence them to have increased interest in GI; while 18.1% with a child said the same. For other potential influencers on interest, the percentage of positive (yes) responses were 17.5% if someone else in the family, 22.6% if a close friend, 23.1% if a neighbor, 19.7% if someone from the neighborhood association, and 28.6% if someone from a City of Knoxville agency or department.

Conclusions and Implications. Results suggest that there is room to increase awareness of specific types of GI among lower- and moderate-income residents, and that backyard GI programs intentionally designed to reach this population could be well received. A spouse/partner, city agency, and/or neighbor may have influential roles in increasing program participation. Findings can be used toward multidisciplinary efforts in which social workers, community organizers, urban planners, county extension agents, and stormwater personnel work together to identify how to reach groups not traditionally served by backyard GI.