What is Green Infrastructure?

June 29, 2015

By Jason Foster, PE

To bring attention to the topic of Green Infrastructure, LDA is doing a blog series about GI with topics including proposed GI stormwater regulations in the State of Tennessee, GI applications in stormwater and wastewater, specific GI controls such as pervious pavement and bio-retention, and GI funding. The term Green Infrastructure has been used interchangeably with terms such as Better Site Design, Smart Growth, and Low Impact Development (LID), often leading to confusion. But how you use GI may very well define what GI is to you. This is the first blog in a series focusing on Green Infrastructure.

Green Infrastructure or GI for short is a force multiplier. A force multiplier is a strategy used to increase the effectiveness of conventional design and infrastructure. Green Infrastructure takes a holistic approach that promotes the use of natural systems for infiltration, evapotranspiration, and the harvesting and use of rainwater. GI can provide a combined benefit for design and infrastructure by improving water quality, decreasing energy consumption, and increasing the sustainability of new facilities.

For example, using GI to limit the effects of development is more appropriately called Low Impact Development (LID), and a focus on sustainability by reducing energy consumption and renewable commodities is more suitability defined as Sustainable Design or Light Imprint Design.

The US Environmental Protection Agency (EPA) seeks to better separate GI from other terms like Low Impact Development in this excerpt from “Low Impact Development Distinguishing LID from other Techniques that Address Community Growth Issues”. This excerpt highlights the difficulty of distinguishing one goal or strategy where GI is used from another, or even GI itself.

The EPA website says “In the context of stormwater, GI refers to engineered-as-natural ecosystems such as green roofs, porous pavement, swales and rain gardens (which are also LID practices) that largely rely on using soil and vegetation to infiltrate, evapotranspirate, and/or harvest stormwater runoff and reduce flows to drainage collection systems. In this context, it is often used interchangeably with Green Stormwater Infrastructure or Wet Weather Green Infrastructure. Considered collectively, GI is an integrated system of natural elements and LID practices that provide broad environmental benefits. For many, GI is becoming an umbrella term under which other terms, such as LID, fit.”

LDA’s engineers work with water, all kinds of water, drinking water, wastewater, and stormwater. We enjoy exploring not only the varied benefits of GI, but the technical aspects as well. How does it work? What makes it work? How is GI best applied?

LDA invites you to contact us and our engineers to join our discussion and share your thoughts and questions about GI.