Over the past few weeks, we’ve been thinking a lot about the intended and unintended impacts of green stormwater infrastructure (GSI). As with any project planning and implementation process, GSI projects are accompanied by their fair share of intended and unintended outcomes throughout the span of their timelines.

While at the base of its design, GSI incorporates tools and systems that manage stormwater to improve water quality and reduce flooding, GSI additionally amplifies the social, environmental, and economic benefits of the triple bottom line (TBL). The reduction of stormwater runoff, improvement in water quality, mitigation of urban heat island effect, restoration of natural wildlife habitats, the formation of greened acres and recreation spaces, and increased economic opportunities, to name a few…

In Philadelphia, the intended impacts of GSI as described in Green City, Clean Waters are already being realized, as are additional unintended outcomes—many of which are proving to be equally beneficial in an economic and social context. October’s GSI Partners Quarterly Meeting functioned as a collective dialogue on the intended and unintended outcomes of attendees’ work and also provided the opportunity to think about the potential for social impact through GSI as it relates to a community’s well-being. Although more difficult to directly measure, there is mounting evidence that GSI projects are improving the health and safety of their surrounding communities. Results from presenter Dr. Michelle Kondo’s research indicate there is the opportunity and need for additional research to further understand the social impacts of GSI.

In thinking through current and future partnerships involved with stormwater management planning and implementation processes, we should be cognizant of a project or plan’s potential to generate social impact and growth within the surrounding community. With this, there are opportunities to approach social impact proactively, thinking about it throughout a project’s whole timeline, rather than in hindsight. Can we incorporate the triple bottom line framework into the design and implementation process rather than simply analyzing them as added value or bonus outcomes at a project’s end?


With development and redevelopment comes the opportunity, for both private and public ventures, to approach GSI projects in a way that maximizes for triple bottom line impact. Is it possible to shift what we identify as unintended outcomes to intended? How can we use our learnings to inform our own future practices and those of our peers?