TOWARD A MORE INCLUSIVE DEFINITION OF GREEN INFRASTRUCTURE: “Green infrastructure is broadly understood to be a good thing, but many city plans lack a clear definition of what it actually is. Hydrological definitions dominate. This narrow view can cause cities to miss out on vital social and ecological services that more integrative green infrastructure can provide,” stated Dr. Zbigniew Grabowski, Cary Institute of Ecosystem Studies, lead author of a nationwide analysis of GI plans from 20 American cities (January 2022)
Note to Reader:
A new nationwide analysis of 122 plans from 20 United States cities found that many plans fail to explicitly define green infrastructure. When they do, concluded the Cary Institute of Ecosystem Studies, they tend to focus on stormwater management, favoring engineered facilities over parks and larger urban green spaces. The study is the first systematic review of the use and definition of the green infrastructure concept in US city plans. The January 2022 news release by the Cary Institute is reproduced in full below.
Toward a more inclusive definition of green infrastructure
Green infrastructure has been embraced as a tool to help cities achieve sustainability and resilience goals while improving the lives of urban residents. How green infrastructure is defined guides the types of projects that cities implement, with enduring impacts to people and the urban environment.
A new nationwide analysis of 122 plans from 20 US cities, published today in Frontiers in Ecology and the Environment, found that many plans fail to explicitly define green infrastructure. When they do, they tend to focus on stormwater management, favoring engineered facilities over parks and larger urban green spaces. The study is the first systematic review of the use and definition of the green infrastructure concept in US city plans.
Photo Credit: Timon McPhearson
Hydrological Definitions Dominate
Lead author Zbigniew Grabowski, who completed the work as a postdoctoral associate at Cary Institute of Ecosystem Studies, explains, “Green infrastructure is broadly understood to be a good thing, but many city plans lack a clear definition of what it actually is. Hydrological definitions dominate. This narrow view can limit project funding and cause cities to miss out on vital social and ecological services that more integrative green infrastructure can provide.”
Green infrastructure has its roots in 19th century landscape design. Its original conceptualization was broad, taking in parks, trail systems, gardens, and other natural landscape features that provide benefits for people and the environment. This shifted in 2007, when the US Environmental Protection Agency defined green infrastructure as a set of best practices for managing stormwater, to meet Clean Water Act regulations.
Coauthor and Cary Institute scientist Steward T.A. Pickett notes, “While the landscape concept of green infrastructure includes stormwater management benefits, stormwater concepts rarely consider the broader landscape. This can mean lost opportunities for more expansive benefits, among them high-quality green spaces, management of diverse environmental risks, and improved urban public health.”
Overview of the Research Findings
The team’s nationwide analysis explored: the types of city plans that define green infrastructure, how it is defined, and the functions and benefits assigned to green infrastructure projects. Twenty medium to large US cities, representing the major biomes, were included. City plans (303) were collected and screened for references to green infrastructure, with 122 meeting criteria for analysis. These included comprehensive/strategic, sustainability, watershed restoration, and climate plans.
Cities that were part of the assessment: Atlanta, Austin, Baltimore, Chicago, Denver, Detroit, Louisville, Miami, Milwaukee, New Orleans, New York City, Philadelphia, Phoenix, Portland, Sacramento, San Juan, Seattle, St. Louis, Syracuse, and Washington DC.
Among the team’s findings: 39% of plans that refer to green infrastructure do not define what it is. Of those that do, stormwater concepts predominate (59%), followed by landscape concepts (17%), ‘integrative’ — which combine stormwater and landscape concepts (15%), and other (9%). Across plans containing definitions, 57% had several different definitions, with a total of 153 unique definitions identified, indicating that green infrastructure means different things to city planners across the US.
What qualifies as green infrastructure also varied widely. Across GI definitions, 693 different types of green infrastructure were identified. The features most commonly included in plans were trees (90%), rain gardens (75%), ‘other stormwater facilities’ (55%), blue-green corridors (60%), and green roofs (65%). Some cities went so far as to include green energy and alternative transportation technologies within their definitions of GI.
Green infrastructure benefits identified by city plans include water quality, recreation, health, city livability, and property value. Across cities, social benefits were most commonly cited in plans, followed by environmental, economic, ‘built environment’ (to enhance or support existing built structures, like a sewer or transportation system), and ecological benefits. Some cities also identified more specific benefits such as recovery from extreme weather events (e.g. Washington DC), new business opportunities (e.g. Miami), and social revitalization (e.g. Atlanta).
A Comprehensive View of Green Infrastructure
Taking in the breadth of concepts outlined in the 122 plans, the authors developed a synthetic definition of green infrastructure to guide future research and planning, and help cities and researchers adopt a more comprehensive view of what green infrastructure entails and the benefits it confers.
Green infrastructure (GI) refers to a system of interconnected ecosystems, ecological-technological hybrids, and built infrastructures providing contextual social, environmental, and technological functions and benefits. As a planning concept, GI brings attention to how diverse types of urban ecosystems and built infrastructures function in relation to one another to meet socially negotiated goals.
Coauthor Timon McPhearson, a research fellow at Cary Institute and Director of the Urban Systems Lab at The New School, concludes, “The US is poised to make large scale, needed, investments in urban infrastructure. To ensure these investments build environmental resilience in a way that benefits the lives of all urban residents, we’ve put forth a more comprehensive definition of green infrastructure, to guide planning, policy, and practice — with the goal of facilitating more equitable urban greening.”
Across the country, advocacy organizations, communities, planners, researchers, and practitioners are working to transform urban planning to better address equity and justice issues. To support these efforts, the research team created a website to share deeper project findings, resources, and recommendations for the 20 cities examined.
To Learn More:
Download a copy of the research paper, What is green infrastructure? A study of definitions in US city planning, as published in Frontiers in Ecology and the Environment,
Also, click on Toward a more inclusive definition of green infrastructure to download a PDF copy of the news release above.
What is “Green Infrastructure”? – Looking back to understand the origin, meaning and use of the term in British Columbia
In June 2004, the British Columbia Green Infrastructure Partnership (GIP) released a Consultation Report which included a comprehensive definition of “green infrastructure”. Three years later, in June 2007, the first in the Beyond the Guidebook series of guidance documents provided a clear distinction between natural and engineered green infrastructure.
The Beyond the Guidebook Series builds on the technical and philosophical foundation provided by Stormwater Planning: A Guidebook for British Columbia, released by the British Columbia Ministry of Environment in June 2002. The Guidebook articulated a ‘design with nature’ approach to community design.
Built and Natural Environments are Connected:
So, Design with Nature!
The Green Infrastructure Partnership (GIP) was formed in 2003 to promote an integrated approach to land development and infrastructure servicing that addresses the need for coordinated change at different scales – that is: region, neighbourhood, site and building.
Water Sustainability Action Plan
The GIP was one of six elements that made up the Water Sustainability Action Plan for British Columbia, released in February 2004. The six elements holistically link water management with land use, development and resource production.
“Under the umbrella of the Water Sustainability Action Plan, the GIP mission was to facilitate implementation of infrastructure practices and regulation province-wide that embody a ‘design with nature’ way-of-thinking and acting,” states Kim Stephens, a founding member of the GIP Steering Committee and currently Executive Director, the Partnership for Water Sustainability in BC.
“An over-arching goal of this approach is to protect and/or restore the natural environment by improving the built environment. This is the essence of why we design with nature.”
After incorporation of the Partnership for Water Sustainability in BC as a not-for-profit society in 2010, the responsibilities of the GIP were assumed by the Partnership for Water Sustainability.
Beyond the Guidebook: Context for Rainwater Management and Green Infrastructure in British Columbia (2007)
“In recent decades, the British Columbia landscape has been transformed by settlement and economic growth. While the province has been experiencing enhanced social and economic well-being, it has also experienced avoidable cumulative environmental impacts. The latter are due to pressures on land and water resources.
“The desire to mitigate environmental impacts has provided a driver for a ‘green infrastructure’ movement that is water-centric and is founded on a natural systems approach.
“Through implementation of ‘green infrastructure’ policies and practices, the desired outcome in going Beyond the Guidebook is to apply what we have learned at the site scale over the past 10 to 15 years…so that we can truly protect and/or restore stream health in urban watersheds,” concludes Kim Stephens.
Distinguishing Natural from Engineered Green Infrastructure
“Two complementary strategies can ‘green’ a community and its infrastructure: first, preserving as much as possible of the natural green infrastructure; and secondly, promoting designs that soften the footprint of development,” wrote Susan Rutherford in 2007. At the time, she represented West Coast Environmental Law (WCEL) on the GIP Steering Committee.
Susan Rutherford was the author of The Green Infrastructure Guide: Issues, Implementation Strategies and Success Stories, May 2007, a deliverable under the Outreach and Continuing Education Program undertaken by the Green Infrastructure Partnership.
“Green infrastructure design is engineering design that takes a ‘design with nature’ approach, to both mitigate the potential impacts of existing and future development and growth and to provide valuable services.”
Legal and Policy Strategies to Support Green Infrastructure (2007)
“The Green Infrastructure Guide traces some of BC’s local government experience in implementing engineered green infrastructure designs,” wrote Susan Rutherford.
“The Guide’s purpose is to encourage successful designs, by reporting on what the legal and policy strategies are, what some of the implementation hurdles (and solutions) have been, and how they have been effective in achieving sustainability goals.
“The intent is to support the efforts of local government officials and decision-makers to green their community’s infrastructure, by sharing the tools and the collective wisdom that have been gained as a result of implementation experiences from around the province.”
Green Infrastructure Defined (2004)
“Using a narrow interpretation, green infrastructure refers to the ecological processes, both natural and engineered, that are the foundation for a healthy natural and built environment in communities,” wrote Deborah Curran for the GIP’s 2004 Green Consultation Report. Deborah was the original WCEL representative on the GIP Steering Committee.
“Municipalities using the green infrastructure as an integral part of how development occurs find that it is often less costly than hard infrastructure, and also offers aesthetic, environmental, health and recreational benefits.”
“Using the green infrastructure to manage common processes, such as rainwater runoff, keeps water on the land longer, thus recharging aquifers while protecting stream hydrology and morphology.
“Street trees, greenways and rooftop gardens, the ‘urban forest’, help mediate summer heating in developed areas, restore pre-development levels of evapotranspiration, and sequester pollution while providing habitat for many species.
“Green infrastructure in neighbourhoods, such as green streets, constructed wetlands, protected stream corridors and new greenways, are seen as amenities and increase property values.
“Finally, maintaining working lands is important both for the economy and for their contribution to the green infrastructure of a region,” concluded Deborah Curran.
To Learn More:
Read the Report on the Green Infrastructure Consultation Held on May 11, 2004 in Vancouver .
Read Beyond the Guidebook: Context for Rainwater Management and Green Infrastructure in British Columbia, released in June 2007.
Read The Green Infrastructure Guide: Issues, Implementation Strategies and Success Stories, released in 2007.