Infrastructure tells a material story of ongoing challenges in cities, reflecting the diverse, normative desires of different communities. In this article we examine the introduction of green infrastructure technologies into urban infrastructure systems to think critically about these challenges and desires. Green infrastructure is an intentionally designed, multifunctional technology that directly uses or mimics the ecological processes of soils and plants (e.g., green rooftops, rain gardens, and bioswales). Facing budget shortfalls as well as demands to mitigate hazards and green the city, urban leaders are looking at green infrastructure as a facility that can provide diverse cobenefits along with traditional services. A focus on stormwater-based metrics, however—effectively reframing green infrastructure as green stormwater infrastructure—discursively tamps down alternative politics and desires for the city. Through a case study of Pittsburgh’s stormwater governance, we argue that the work to (re)technologize green infrastructure as green stormwater infrastructure is an act of depoliticization that hinders needed conversations about just infrastructure outcomes. We draw on themes from qualitative interviews with community members engaged in urban water governance to suggest that these moments of transition provide an opportunity to illuminate previously obscured infrastructure politics and challenge the forms of knowledge that bind us to conventional routines of urban environmental governance. We see an opportunity to reframe the conversation in a way that opens up opportunities for historically disenfranchised communities to voice their needs beyond the technocratic problem of stormwater management.

Nature-based solutions (NbS) have emerged as a key strategy for sustainably addressing multiple urban challenges, with rapidly increasing knowledge production requiring synthesis to better understand whether and how NbS work in different social, ecological, economic, or governance contexts. Insights in this Perspective are drawn from a thematic review of 61 NbS review articles supported by an expert assessment of NbS knowledge in seven global regions to examine key challenges, fill gaps in Global South assessment, and provide insights for scaling up NbS for impact in cities. Eight NbS challenges emerged from our review of NbS reviews including conceptual, thematic, geographic, ecological, inclusivity, health, governance, and systems challenges. An additional expert assessment reviewing literature and cases in seven global regions further revealed the following: 1) Local context-based ecological knowledge is essential for NbS success; 2) Improved technical knowledge is required for planning and designing NbS; 3) NbS need to be included in all levels of planning and governance; 4) Putting justice and equity at the center of urban NbS approaches is critical, and 5) Inclusive and participatory governance processes will be key to long-term success of NbS. We synthesized findings from the NbS review results and regional expert assessments to offer four critical pathways for scaling up NbS: 1) foster new NbS research, technological innovation, and learning, 2) build a global NbS alliance for sharing knowledge, 3) ensure a systems approach to NbS planning and implementation, and 4) increase financing and political will for diverse NbS implementation.

Green stormwater infrastructure (GSI) is increasingly used to comply with stormwater management requirements under the Clean Water Act, but there is growing interest in leveraging GSI as part of climate change adaptation strategies. Success in contributing to this goal depends on what types of GSI are being used and how they are sized. Here we review GSI design storm requirements for the seven Urban Resilience to Extremes Sustainability Research Network (UREx SRN) cities in the United States. We find that while GSI in most of our study cities is designed for smaller, more common precipitation events (e.g., 1-year event) considered by current water quality regulations; GSI in several UREx cities is primarily focused on flood control and require design for much larger storms (e.g., 100-year events). In order for GSI to contribute to climate change adaptation, it is critical to ensure that design guidelines align with that goal.

Infrastructure crises are not only technical problems for engineers to solve—they also present social, ecological, financial, and political challenges. Addressing infrastructure problems thus requires a robust planning process that includes examination of the social and ecological systems supporting infrastructure, alongside technical systems. An integrative Social, Ecological, and Technological Systems (SETS) analysis of infrastructure solutions can complement the planning process by revealing potential trade-offs that are often overlooked in standard procedures. We explore the interconnected SETS of the infrastructure problem in the US through comparative case studies of green infrastructure (GI) development in Portland and Baltimore. Currently a popular infrastructure solution to a wide variety of urban ills, GI is the use and mimicry of ecological components (e.g., plants) to perform municipal services (e.g., stormwater management). We develop the ecological-technological spectrum—or ‘eco-techno spectrum’—as a framing tool to bridge all three SETS dimensions. The eco-techno spectrum becomes a platform to explore the institutional knowledge system dynamics of GI development where social dimensions are organized across ecological and technological aspects of GI, exposing how governance differs across specific forms of ecological and technological hybridity. In this study, we highlight the knowledge system challenges of urban planning institutions as a key consideration in the realization of innovative infrastructure crisis ‘fixes.’ Disconnected definition and measurement of GI emerge as two distinct challenges across the knowledge systems examined. By revealing and discussing these challenges, we can begin to recognize—and better plan for—gaps in municipal planning knowledge systems, promoting decisions that address the roots of infrastructure crises rather than treating only their symptoms.

Green stormwater infrastructure (GSI) is part of a suite of sustainability initiatives that are vital to tackling climate change. However, siloed governance structures that traditionally implement stormwater infrastructure are not well-suited to address the cross-cutting goals of such initiatives (i.e. incorporating social equity along with technological aspects). Equity planning centers social equity in policy development and can help ameliorate this siloing. Here, we apply equity planning concepts to examine GSI incentive programs developed in the United States to address current funding gaps. We explore GSI incentive programs included in federally-mandated Stormwater Management Plans (SWMPs). Programs found through a scan of readily available SWMPs ranged from $20 rebates to $500,000 grants, providing a range of opportunities. However, closer analysis of application materials suggests potential institutionalization of inequality through restricted access. Barriers to accessing these programs can limit participation by marginalized or under-resourced communities and instead redirect scarce resources to communities who already have strong capacity. Thus, we argue that centering equity in the development of sustainability incentives and conducting meaningful equity analysis should be applied to GSI programs to reform practice and avoid institutionalizing inequity.