Green Infrastructure, Gray Infrastructure, & More
In deciding how best to confront flooding or water quality problems, localities often employ a mix of two types of infrastructure. Traditional gray infrastructure involves human-engineered facilities such as detention basins and underground pipes that centrally capture and convey stormwater to a local waterbody. Green infrastructure (GI) is a decentralized approach that relies on natural land, working landscapes, pervious pavement, and buffer strips to absorb or capture rainfall where it falls, recharging the groundwater aquifer, reducing stormwater runoff and the pollutants and sediment that accompany it or storing it for later re-use.
Many communities have begun to add green infrastructure components to traditional gray solutions. Green infrastructure is often the most cost-effective way to manage stormwater from regular rain events, as most systems can be designed to easily capture the first inch of rainfall. Gray infrastructure is almost always needed to manage precipitation from larger storms.
With the right design, GI practices can be applied in almost any setting, including urbanized areas where stormwater controls can be integrated into existing features. The repair of roadways, parking lots, and sidewalks, as well as the upgrading of sewer systems, present opportunities to consider GI alternatives, including Green Streets.
For more information on green streets, see here.
“Valley Forge Trout Unlimited Sidley Basin Stormwater Retrofit”, Images courtesy of Meliora Design and Viridian Landscape Studio
As shown in this before-and-after picture, GI projects can transform the appearance of a local community.
An increasing number of studies suggest that green infrastructure can have a positive impact on human health and well-being, as the presence of green space not only inspires a stronger sense of community but also has been linked to more tangible benefits, such as reduced levels of inner-city crime and violence.
Both gray and green infrastructure require ongoing maintenance.
For more information, see New Jersey Future’s Green Infrastructure Municipal Toolkit or the New Jersey Department of Environmental Protection’s website.