Pipes or People? An Analysis of Green Stormwater Infrastructure Co-benefits to Accelerate Regime Change

Abstract

Green stormwater infrastructure (GSI) complements grey infrastructure to help prevent combined sewer overflows; however, studies show that it is rarely implemented at scale in North American cities (Croeser et al., 2021; Goulden et al., 2018; O’Donnell et al., 2021; Sarabi et al., 2019). For GSI to trigger a full infrastructure transition or regime change (Brown et al., 2009; Chini et al., 2017; Olsson, 2003), communities must actively participate in designing, constructing, and managing these decentralized systems, and public agencies must adapt by managing increasingly complex physical, social, and ecological networks. Like many infrastructure transformations, this shift is less about technology and more about navigating the social and spatial challenges of coproduction. This study identified key factors influencing the shift toward decentralized green stormwater infrastructure (GSI) systems by connecting the physical dynamics that shape both networked and standalone infrastructure with the benefits of ecological restoration and social equity. I analyzed ten years of GSI projects, from 2011-2021, in two early adopter cities, Milwaukee, Wisconsin, and Philadelphia, Pennsylvania, to distill the relationship between the physical structures and the social forces that affect GSI implementation. I hypothesized that (1) Co-produced GSI positively contributes to urban greenness, as measured with normalized difference vegetation index (NDVI) data, and some GSI technologies are more effective than others, and (2) GSI adoption has spatial trends that can be attributed to social-cultural factors such as agency capacity, social and economic factors, and community capacity. Findings reveal that place-based factors, including GSI technologies and structures, contribute to regime change and that the use of remote sensing data and methods can enhance GSI management practices. The study also suggests that measuring co-benefits via remote sensing could bolster accountability regarding the social-cultural factors essential to sustainable city regimes, thereby solidifying new practices and reinforcing system values. The findings also indicate that a deeper understanding of physical and social-cultural factors can provide concrete recommendations to advance regime change. The interdependencies reinforce the multidisciplinary nature of regime change and the need for integrative approaches, the reinvention of urban typologies, and shifts in adaptive management to transition from a regime of pipes to one focused on people and places.