How to Determine the Best Green Infrastructure Options
By Kirsten Anderer Sep 24, 2012
Have you been hearing a lot about green infrastructure and do not know what it means? Green infrastructure is a relatively new concept that is currently growing in popularity every day. More and more municipalities are incorporating green infrastructure into their water and wastewater projects, and reaping the benefits.
What is Green Infrastructure?
So, what is green infrastructure, really? The U.S. Environmental Protection Agency (EPA) defines it as the use of “natural hydrologic features to manage water and provide environmental and community benefits.” Basically, it is the management of storm water where it falls, instead of collecting and transporting it to another location for disposal.
By weaving natural processes into the built environment, green infrastructure provides not only storm water management, but also flood mitigation, air quality management and much more. This approach helps maintain healthy waters, provide multiple environmental benefits and support sustainable communities.
Types of Green Infrastructure Projects
There are a variety of products, technologies and approaches that a municipality could implement to meet the intent of green infrastructure. The purpose and function of green infrastructure projects is to naturally manage storm water, especially in urban areas. These types of projects go hand-in-hand with low-impact development and sustainable community initiatives.
Projects could be as simple as building tree boxes into the sidewalks or as complex as stream restoration. Tree boxes not only provide a better environment for the trees, but also create more pervious surfaces. Restoration returns the stream back to its natural environment, which can prevent erosion and its detrimental impact to surface waters.
Creating more pervious surfaces can easily be done at water and wastewater facilities by constructing green roofs on new or existing buildings, installing pervious pavement in parking lots and roadways, and creating bioswales instead of using concrete pipes or channels that transport storm water away from the facility to be dealt with downstream. Storm water can be collected from building rooftops, also known as rainwater harvesting, and reused for irrigation of facility grounds and landscaping, rather than using potable water for that purpose. Creating wetlands onsite provide a natural method for cleaning pollutants out of the storm water and mimicking natural retention time of the runoff.
Benefits of Green Infrastructure
Green infrastructure not only improves the environment and oftentimes involves preserving open space, but it can also save municipalities money by creating a new water source or eliminating costly treatment of storm water runoff. In addition, the EPA encourages the use of green infrastructure as a means of complying with combined sewer overflow (CSO) enforcement agreements and in storm water permits. By incorporating green infrastructure into water and wastewater projects, many states offer additional priority points for their state revolving fund (SRF) project ranking, which can help a municipality obtain funding for these types of projects.
Implementing Green Infrastructure Approaches
At a time when so much water infrastructure is in need of replacement or repair and so few municipalities have the funding to fix it, resilient and affordable solutions that meet many objectives at once are needed. Green infrastructure is one possible solution.
To determine if green infrastructure projects are the right approach for your municipality, visit the EPA’s website at water.epa.gov/infrastructure/greeninfrastructure. More information and resources are available there, as well as case studies to learn what other municipalities are doing.
Kirsten Anderer is an engineer with the Drinking Water State Revolving Fund Team for the United States Environmental Protection Agency (EPA).