Graham Sustainability Institute

Green Stormwater Infrastructure on Vacant Land: An Integrated Assessment with Implications for Detroit

August 2019

Authors:
Joan Iverson Nassauer, Natalie R. Sampson, Noah J. Webster, Margaret Dewar, Shawn McElmurry, G. Allen Burton Jr., & Catherine Riseng.

Report topic:
A summary of refereed literature that addresses social and environmental performance and governance of GSI, and results of NEW-GI’s analyses of the performance of bioretention garden pilot sites in Detroit’s Warrendale neighborhood. This report integrates assessments of water quality, stormwater flows, residents’ preferences, neighborhood well-being, and the maintenance characteristics of 18 different design alternatives for GSI on vacant property in residential neighborhoods.

NEW-GI (Neighborhood, Environment, and Water research collaborations for Green Infrastructure) contributes to knowledge about green infrastructure in legacy cities by integrating research about water quality, community well-being, governance, and ecological design. Involving community, government and academic collaborators, it produces evidence-based guidance for sustainably managing stormwater in ways that enhance landscapes and the lives of residents in Detroit and other legacy cities.

NEW-GI ecological designs link Detroit’s vacant property demolition process with new forms of green stormwater infrastructure (GSI) that aim to manage stormwater as well as increase nearby residents’ well-being. This research uses a transdisciplinary design-in-science approach in which researchers, practitioners, and community members work together to contribute knowledge addressing social and ecological objectives. NEW-GI researchers assess the performance of different GSI designs and governance approaches. This assessment provides evidence for making decisions about how GSI can better achieve objectives.

This report describes the potential and performance of neighborhood scale green stormwater infrastructure (GSI) on vacant land in Detroit. It combines an integrated assessment of NEW-GI pilot garden designs constructed on vacant residential properties in the Warrendale neighborhood in 2015 with a summary of relevant scholarly literature and describes the implications for implementing GSI in Detroit. Results from our field measurements of pilot sites and our surveys of neighborhood residents provide very specific information about how these GSI sites manage stormwater, what residents prefer, and how they anticipate alternative GSI designs might affect their health and well-being. Our integrated assessment allows decisionmakers and residents to consider trade-offs among design alternatives, including maintenance requirements, for the Warrendale pilot sites. Key findings were:

  • GSI bioretention systems on the pilot sites perform extremely well to manage stormwater flows and reduce peak flows, far exceeding the capacity needed for the 2-year design storm.
  • After living near the pilot site designs for two years, residents strongly prefer the design of the existing pilot sites that include low-growing flowering plants and bollards.
  • Nearby residents also perceive alternative designs as attractive and safe, and have strong preferences for alternatives that include mown turf and flowering plants while maintaining open sight lines.
  • All alternatives that look safe and well-cared-for enhance mental health and anticipated healthy behaviors, including walking in the neighborhood and interacting with neighbors.
  • Maintenance of GSI installations is extremely important for stormwater management functions, resident preferences, and well-being and health benefits to residents.

Finally, based on this evidence, the report recommends widespread adoption of multifunctional GSI in Detroit neighborhoods with careful attention to varying infrastructure needs and opportunities, geomorphological and hydrological characteristics, vacancy patterns, and residents’ preferences across the city.

See also: graham.umich.edu/activity/28598