Why You Should Consider Green Stormwater Infrastructure for Your Community

On this page:

• Infrastructure Overview
• Infrastructure Needs for the United States
• Opportunities to Green the Gray
• Benefits of Greening the Gray
• Green Infrastructure Economic Benefit Resources

Infrastructure Overview

Infrastructure is the basic equipment and structures (such as roads, bridges, buildings, water lines, and sewer systems) that are essential for functional, healthy, and vibrant communities. In order to function properly, infrastructure must be maintained, repaired, or replaced at the end of its life-cycle. Because stormwater runoff has become one of the leading causes of water pollution in urban environments, community leaders and decision-makers are faced with making decisions on how to best manage stormwater in their communities.  

Traditional "gray" stormwater is designed to move urban stormwater away from the built environment and includes curbs, gutters, drains, piping, and collection systems. Generally, traditional gray infrastructure collects and conveys stormwater from impervious surfaces, such as roadways, parking lots and rooftops, into a series of piping that ultimately discharges untreated stormwater into a local water body.  Whereas, "green" stormwater infrastructure is designed to mimic nature and capture rainwater where it falls. Green infrastructure reduces and treats stormwater at its source while while also providing multiple community benefits such as:

• Reducing localized flooding
• Improving community aesthetics
• Encouraging more neighborhood socialization
• Improving economic health by increasing property values and providing jobs opportunities for small businesses
• Decreasing the economic and community impacts of flooding.delivering environmental, social, and economic benefits. 

Infrastructure Needs for the United States

In 2017, the American Society of Civil Engineers (ASCE) released its Report Card for America's Infrastructure .  The Report Card assessed the infrastructure condition and needs of the United States using an A to F school report card format. The grades are assigned according to the following eight criteria:

1. Capacity
2. Condition
3. Funding
4. Future need
5. Operation and maintenance
6. Public safety
7. Resilience
8. Innovation

ASCE evaluated 16 infrastructure categories, including:

• Roads
• Public parks and recreation
• Schools
• Wastewater 
• Drinking Water

The findings of ASCE's assessment shows that the nation is in dire need of infrastructure improvements.  Presently, America's cumulative grade point average (GPA) is a D+.  Capital investment needs for the nation’s wastewater and stormwater systems are estimated to total $298 billion over the next 20 years. Investing in infrastructure is critical for long-term economic growth, increasing the gross domestic product (GDP), employment, household income, and exports.  The reverse is also true -- without prioritizing our nation's infrastructure needs, deteriorating conditions can become a drag on the economy and communities. (Source: ASCE 2017 Report Card for America's Infrastructure)   

Opportunities to Green the Gray

Communities should look for and evaluate opportunities to "green the gray", especially when infrastructure projects will involve stormwater management. Green infrastructure practices can be a viable option for managing stormwater in highly urbanized areas where development density is desired and off site mitigation of stormwater runoff is not a preferred alternative. Green infrastructure practices can be integrated into existing features of the built environment, including streets, parking lots, and public recreational areas such as parks and sports complexes. Expanding the quantity and quality of green spaces, such as green streets, in urban areas is an important tool in protecting and restoring the health of local streams and rivers.  By increasing the green areas in urban environments, stormwater runoff and stream channel erosion can be reduced, thus reducing the volume of pollutants, such as sediment, nitrogen and phosphorus, entering our waterways.  

Infrastrucutre upgrades are necessary to maintain the social, economic and environmental health of a community and present a unique opportunity to integrate green stormwater elements into the gray - "Greening the Gray". Implementing projects in public spaces provides additional benefits and gives communities the opportunity to showcase the aesthetic appeal of green infrastructure practices and provide a visual demonstration of how they can function. This real-life context allows residents, businesses, and local governments to experience the multiple benefits and values of green infrastructure practices includeing more walkable streets, traffic calming, green public spaces, shade, and enhanced foot traffic in retail areas. Communities can then use the experience gained from the design, installation and maintenance of green infrastructure projects to help tailor regulations and incentive programs to make green infrastructure easier to implement in the future.

When to consider the use of green infrastructure:

• Repairing, resurfacing or replacing roadways and parking lots
• Repairing or replacing damaged sidewalks and curbs
• Upgrading or replacing utilities in the public right-of-way (e.g., sanitary sewer systems, storm sewer systems, drinking water supply lines)  
• Redeveloping vacant or abandoned properties

EPA published Green Infrastructure Opportunities that Arise During Municipal Operations to show how integrating green infrastructure practices can enhance retrofits and maintenance projects while also providing multiple community benefits. This document highlights approaches local government officials and municipal program managers in small to mid-size communities can use to incorporate green infrastructure components into work they are doing in public spaces. The guide demonstrates ways in which projects can be modified relatively easily and at a low cost recognizing that municipal resources can be limited. Local governments are in a unique leadership position to further green infrastructure within their communities. EPA hopes that by using this guide localities can begin to institutionalize the use of green infrastructure in their municipal operations.

Benefits of Greening the Gray

Green infrastructure, especially green street practices, are beneficial and feasible for new road construction and retrofits.  These practices can provide substantial economic benefits when used in transportation applications. Billions of dollars are spent annually on road construction and rehabilitation, with a large percentage focused on rehabilitation, especially in urban areas.  

Integrating green infrastructure elements into broader transportation and community connectivity improvements can significantly reduce the marginal cost of stormwater management by including it within larger infrastructure capital improvement projects.  One major concern that communities have regarding green infrastructure is operation and maintenance. However, using roads and right-of-ways as locations for green infrastructure implementation alleviates access and maintenance concerns. 

In addition to the economic benefits and cost savings provided by green infrastructure, green streets offer a host of other social, human health, and environmental benefits. The website Green Cities: Good Health  provides an overview of the scientific evidence of human health and well-being benefits provided by urban forestry and urban greening. Green Cities: Good Health also provides a collection of more than 2,800 scholarly works, most of which are peer reviewed.  The research findings are sorted and summarized across benefit themes that include healing, safety, and community building.  

An increasing number of studies suggest that green infrastructure can have a positive impact on human health and well-being.  Recent research has linked the presence of green space to reduced levels of inner-city crime and violence, a stronger sense of community, improved academic performance, and even reductions in the symptoms associated with attention deficit and hyperactivity disorders.

Green Infrastructure Economic Benefit Resources

• Banking on Green: A Look at How Green Infrastructure Can Save Municipalities Money and Provide Economic Benefits Community-wide (PDF)(44 pp, 990 K)  - A joint report by American Rivers, the Water Environment Federation, the American Society of Landscape Architects and ECONorthwest builds on the current understanding of the cost-effectiveness of green infrastructure and further documents four critical areas in which green infrastructure approaches provide cost-effective ways for communities to save money while also creating safer and healthier places to live.  
   
• The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental and Social Benefits (PDF)(80 pp, 3 MB)  discusses the key considerations involved in assessing the economic merits of green infrastructure practices and examines the steps necessary to calculate a variety of performance benefits gained by implementing green infrastructure practices.
   
• The Economic Benefits of Green Infrastructure: A Case Study of Lancaster, Pennsylvania - The benefit analysis summarized in this report evaluates how installing green infrastructure in the combined sewer system (CSS) area could reduce gray infrastructure capital investments and associated wastewater pumping and treatment costs.

For more information on the economic benefits of green infrastructure, please visit EPA's Green Infrastructure Cost-Benefit Resources page.