Is Green Infrastructure a Universal Good?
University of California, Davis | CLUE Lab
Green infrastructure is being used more and more in cities to provide environmental and social benefits. Planners often assume that green infrastructure is good for all places and all people in their cities. In this research project, we questioned that assumption and asked, is green infrastructure a universal good? We explored whether the use of green infrastructure has promoted equity.
We found that issues with the planning, siting, design, and maintenance of green infrastructure can limit the benefits it provides, particularly in areas that are less privileged. However, we suggest that green infrastructure can be a positive feature of cities if all people affected by it are equitably involved in planning and decision-making.
Learning from green stormwater infrastructure in Baltimore
We studied GSI in Baltimore, Maryland, a city of around 600,000 people located on the Chesapeake Bay.
In Baltimore—as in many cities in the United States—a history of racial segregation has contributed to a highly uneven and inequitable distribution of wealth, power, education, and resources across the city. Practices and policies of disinvestment and discrimination led to the segregation of Baltimore’s African American population into certain less desirable areas of the city.
Baltimore’s total population peaked in the 1950s with a post-war economic boom. After that time, closing factories and migration to the suburbs contributed to a population decline of about 30% in the second half of the 20th century, leaving many neighborhoods in decline and tens of thousands of vacant properties across the city. Today, some of these vacant properties are being used as sites for GSI.
One of the motivations for GSI in Baltimore is preventing nutrients and sediments from reaching the Chesapeake Bay. The Chesapeake Bay has been severely impacted by nutrient pollution, leading to declines in aquatic ecosystems and fisheries. The United States Environmental Protection Agency (U.S. EPA) has established limits for the amount of nitrogen, phosphorus, and sediments that may go into the Chesapeake Bay and its tributaries, and GSI is one of the strategies that Baltimore can use to meet this limit.
All of these factors contribute to making Baltimore an important place to study equity and green infrastructure. In addition, the city is home to the Baltimore Ecosystem Study (BES), a long-term investigation that has produced influential social and ecological research about urban systems for more than 20 years. As a BES project, our research builds on this body of knowledge and the relationships developed over time in Baltimore.
While Baltimore does have these municipal plans that include GSI, the city itself has implemented very little GSI at this point. Some city plans even expect that private developers will be installing GSI.
Therefore, GSI currently found in Baltimore has mostly been installed opportunistically as individual, unconnected projects.
The term “infrastructure” implies a system. However, GSI currently on the ground in Baltimore has not been planned, installed, or maintained in a systematic way.
Is green stormwater infrastructure in Baltimore providing benefits, and for whom?
Whether GSI is installed for regulatory or non-regulatory reasons, there is an underlying assumption that it will provide benefits to urban areas. However, just because GSI can provide a number of benefits doesn’t mean that all GSI does provide those benefits.
We found that GSI in Baltimore is extremely variable in terms of type, design, size, and maintenance. Some of these factors vary with characteristics of the population.
We found a range of scores for each factor, but there was no large difference overall in scores between regulatory and non-regulatory facilities.
However, for regulatory facilities, better scores were found in less affluent neighborhoods, while for non-regulatory facilities, better scores were found in more affluent neighborhoods. This result may reflect differences in design, as well as the fact that many non-regulatory facilities rely on community time and resources for maintenance.
How is green stormwater infrastructure maintained in Baltimore?
Maintenance of GSI is an important consideration that tends to be inadequately addressed. GSI facilities require maintenance to keep vegetation healthy and attractive, as well as to remove trash, sediments, and other materials brought in with stormwater.
Regulatory facilities must have long-term maintenance plans before they are approved. However, these plans are often privately contracted and unenforced, yielding a variety of maintenance outcomes.
For non-regulatory facilities, maintenance is a challenging issue. Long-term funding for GSI maintenance is rare—in fact, most grants only cover installation—and not all organizations can support a GSI facility over a long time period. In some cases, maintenance has been assigned to community volunteers, often without additional support or fully accounting for differences in capacity. Mixed results with maintenance practices that rely on community volunteers have more recently led to a shift toward reliance on partnerships and institutional capacity building. All of these factors contribute to variable outcomes.
Lack of communication or knowledge about GSI facilities across different city agencies can also lead to undesirable maintenance practices. For instance, GSI facilities may be unwittingly weed-whacked by maintenance crews, reducing their capacity to manage stormwater.
Maintenance is recognized as a problem by NGO leaders and other professional stakeholders, but sustainable solutions for GSI maintenance require system-wide changes. Ultimately, resources, burdens, and accountability for GSI maintenance must be planned with consideration for the fact that different communities have different capacities to maintain GSI, and that they may also require different levels of long-term financial and logistical support.
Increasing the equity of green stormwater infrastructure
Our research suggests that in order for GSI to be more equitable:
- The perceptions of all stakeholders must be included throughout the process of planning, design, implementation, maintenance, and evaluation.
- GSI must be treated as a system. Each individual installation should address local needs, desires, and capacities, but all installations should be considered collectively to promote social equity in their distribution, maintenance needs, financial support, and evaluation.
