Green Infrastructure

Issue
Traditional stormwater infrastructure in cities and towns collects and disposes of untreated rainwater through extensive networks of underground pipes and surface water channels. To reduce environmental impacts and costs of managing stormwater, which can carry road pollutants, urban communities are increasingly installing green infrastructure which utilizes engineering techniques that mimic nature.

In place of cement and hard structures, green infrastructure employs vegetation and soil rain to infiltrate where it falls. This allows more water to soak into the ground where it can follow natural soil pathways to waterways.

A growing body of research acknowledges the ability of green infrastructure to restore groundwater recharge. It also reduces peak runoff and its associated pollutants by filtration through the soil. Examples of green infrastructure include permeable pavement in parking lots, parks and basketball courts; rain gardens and bioretention systems at schools and other public facilities; and constructed wetlands designed to filter runoff.

Although green infrastructure is widely recognized as an important stormwater management practice, its effectiveness in controlling runoff and associated pollutants is not fully understood. Research is needed to fill important data gaps.

During a time when much of the nation’s stormwater infrastructure needs to be replaced or repaired, and few communities have the resources to do so, green infrastructure can help communities maintain healthy waters and provide environmental benefits in a more cost effective, sustainable manner.

Action
EPA researchers are working to evaluate how different green infrastructure facilities, such as open forest spaces, rain gardens, porous pavements, cisterns, and grassy swales, control runoff and associated pollutants at the source.

Results and Impact
EPA’s research results are anticipated to provide information that can inform and advance the use of green infrastructure in communities across the United States.

EPA has also developed a Strategic Agenda to Protect Waters through Green Infrastructure, and is working with a variety of organizations, including coalition members, partner communities, and approximately 100 supporting organizations, to help expand the use of sustainable, green methodologies for managing stormwater.

Technical ContactYusuf Mohamoud

Collaborations

• U.S. EPA Landscape Ecology Branch
• National Risk Management Research Laboratory
• US Geologic Survey