What is Green and Blue Infrastructure?

Trinity Brown
University of Louisville Resilience Justice Project

Green and Blue Infrastructure
Green and blue infrastructure (GBI) is infrastructure within an area that is made up of green and blue spaces. Green spaces include parks, greenways, and vegetation, and blue spaces include watersheds, streams, and wetlands. Well-maintained green and blue infrastructure benefits its community. Communities with well-maintained GBI have fewer negative impacts on their health and increased property values. GBI that is not well- maintained, or a lack of GBI, contributes to higher rates of asthma, childhood obesity, and urban heat, among other health problems. GBI is an essential component to environmental justice, and low-income communities and/or communities of color are most often negatively impacted by its absence.

GBI in Louisville, KY
Louisville, KY’s most vulnerable communities do not have adequate green and blue infrastructure. In a study conducted by the University of Louisville’s Resilience Justice Project in 2020, fifteen marginalized neighborhoods were studied to assess GBI using the three measures of GBI. These three measures are tree density, public park acreage per 1,000 residents, and percentage of impervious surfaces in a neighborhood (a higher percentage means a lower volume of GBI). Out of the fifteen marginalized neighborhoods studied, all of them were below the city average for two measures of GBI and thirteen neighborhoods were below the city average for all three measures of GBI. These findings are represented in the table below.

Louisville GBI table

How to Improve GBI
A method used to improve green and blue infrastructure is co-governance. Co-governance is when there is shared power between communities and the governmental entities that serve those communities. Co-governance is a hybrid of the top-down and bottom-up participatory processes that aims to increase power at the grassroots level. One way to implement co- governance into GBI planning is to create new legal entities for green and blue infrastructure projects that have governmental authority while also involving the communities’ residents in a manner that creates shared power. Another way is to create community-based entities like resident councils that have the authority to make decisions that is shared with existing governmental entities for the development and maintenance of green and blue infrastructure within communities.

Green Gentrification
In past efforts to increase green and blue infrastructure in low-income communities and communities of color, property values rose, and land developers took interest in land development as green spaces increased and improved. As a result, properties were built and revitalized, and those communities became too expensive for its residents. People of low income and people of color were driven out of their neighborhoods and the neighborhoods became whiter and wealthier. This is green gentrification. In current and future efforts to increase GBI in low-income communities and communities of color, preventative measures should be taken to limit green gentrification in order to further environmental justice and resilience justice. Ways to prevent green gentrification are to pace neighborhood improvements, to create community land trusts and housing trusts, and to connect policies surrounding neighborhood housing affordability with programs that improve neighborhood green and blue infrastructure.

Sources & Resources

  • Arnold and Resilience Justice Project Researchers, Resilience Justice and Community-Based Green and Blue Infrastructure, 45(3) William & Mary Environmental Law & Policy Review 665-737 (2021).

About the Author
Trinity Brown is a Resilience Justice Fellow in the University of Louisville Resilience Justice Project and a second-year law student at the University of Louisville Brandeis School of Law.

Phot of GBI