Reading the Green Landscape: Public Attitudes toward Green Stormwater Infrastructure and the Perceived Nonmonetary Value of Its Co-Benefits in Three US Cities

Abstract

Green stormwater infrastructure mirrors natural hydrologic processes and is presented as an alternative or complement to traditional gray stormwater infrastructure, which uses concrete channels and pipes to convey flows away from neighborhoods. To encourage green infrastructure installation, practitioners promote co-benefits, also called ancillary social, ecological, and environmental benefits. Co-benefits are accrued at the neighborhood-scale, yet the public is not often asked to weigh in on its preferred outcomes. This study surveys the public with a goal to move beyond economic valuation to obtain a better understanding of preference for green infrastructure and how respondents value co-benefits. A representative sample of residents in three US cities (Philadelphia, Pennsylvania; Denver, Colorado; and Seattle, Washington) were presented informational material and then queried for their preference for different infrastructure types and 16 co-benefits. Results show that preferences for stormwater infrastructure, as well as value assigned to associated co-benefits, vary across cities and different demographic groups. Of the three cities in this study, Philadelphia residents had a higher preference for gray infrastructure to handle stormwater in their neighborhood. As the level of survey respondent’s educational attainment increased, so did their preference for new installations of green infrastructure. Perceived value of co-benefits was generally high but varied across different co-benefit/demographic group pairings. The value of community amenity benefits (e.g., increased recreational opportunities) was found to vary between study cities. Public attitudes toward increased property values varied by age and race; attitudes toward community gardens varied by economic security; and attitudes towards improved water quality varied by race. Study results show that stormwater infrastructure and co-benefits are not valued uniformly across demographic groups and vary regionally. We advocate that practitioners engage a representative subset of the population within the appropriate area, especially where infrastructure is planned, to ensure stormwater solutions promote social and environmental equity.