What is Green Infrastructure?
As a resident of Burlington, Vermont and an environmental sciences student, it’s hard not to notice the downhill movement of rain to Lake Champlain when a large storm rolls through. Sediment, heavy metals, bacteria, and phosphorus gradually join the swirling mixture until it reaches the closest body of water or gutter. That rainfall, although an innocuous event, signifies a deeper problem within our community: managing our stormwater.
From the “resident of Burlington” perspective, this kind of a storm may mean driving across miniature rivers in the streets, property damage from erosion, or perhaps a closed day at the beach. From the “environmental sciences student” perspective, this surplus of water signifies alarm bells ringing to the tune of eutrophication. Eutrophication happens when increased nutrient loads reach the nearest body of water—Lake Champlain, in this case—and cause algal blooms, which effectively take the oxygen out of the lake and can subsequently kill the organisms that occupy it. Eutrophication is a global problem that happens to be exacerbated in Burlington due to the urban expansion uphill of Lake Champlain and other causes.
Over the past year, I have been working as an intern through University of Vermont (UVM) Extension, Lake Champlain Sea Grant, and the Vermont Department of Environmental Conservation (DEC) to delve into an effective and simple solution to this stormwater problem: Green Infrastructure.
Green Infrastructure (GI) can be defined as the natural systems that surround us, like forests, wetlands, and soil, plus the nature-based infrastructure, like rain gardens and constructed wetlands, that are engineered to bring the strategies and processes of natural systems into the built environment. Both the natural and engineered systems are doing work for our communities, like improving water quality and creating habitat. Green Infrastructure is much broader in scope than many people realize and can encompass vegetated swales, permeable pavers, infiltration steps, or filter berms. The main mantra of GI, in regard to stormwater, is to "slow it down, spread it out, and soak it in."
Examples of Green Infrastructure
- Rain garden: depressed area of vegetation to clean stormwater runoff from roads, driveways, parking lots, and roofs
- Rain barrel: large container to collect roof/gutter runoff water for future use
- Vegetated swale: broad shallow channel to move and infiltrate stormwater
- Permeable paver: a type of pavement that allows rainwater to filter through it
- Infiltration steps: crushed stone used on sloping pathways or in wooden steps
- Filter berm: a temporary ridge of stone to slow flow and retain sediment from a traffic area
In contrast to Grey Infrastructure (conventional pipes/tubes to move water away from its source), GI works efficiently by mimicking the water cycle. Stormwater flows over a more pervious surface and is able to infiltrate into the ground at an increased rate rather than act as runoff. GI doesn’t necessarily have to entail the construction of a whole new system and can include activities such as restoring a wetland habitat, building a park, or even planting a tree.
As an intern, this definition has shifted and changed for me over the past year. I began to focus more on the human aspect and the types of relationships people typically have with these systems. The average person may want to do their part to help the environment but is often unsure of where to start. Barriers to adopting GI systems often vary based on location and accessibility and, in the case of New England, may include the effects of colder climates on operation and maintenance.
By producing educational materials for homeowners and municipalities, Lake Champlain Sea Grant, UVM Extension, and Vermont DEC smooth this transition from grey to green. Some of the most memorable projects that I have had the pleasure of working on include: revising the current “Vermont Rain Garden Manual” (soon to come!), compiling research on the maintenance aspect of GI, or helping to organize the Green Infrastructure Summit right at the UVM Davis Center.
In Vermont, we have community members that deeply care about and advocate for the Lake Champlain basin. We have an opportunity to pioneer effective Green Infrastructure practices and inspire other states to do the same. Homeowners, not just municipalities, can build a rain garden or plant a tree. They can advocate for permeable pavers and incorporate natural plants into their own stormwater management. If a system works in slowing it (the rainwater) down, spreading it out, and soaking it in, GI is in place and working to enhance Vermont’s natural ability to manage stormwater.
Water quality impacts each and every one of us. When humans take a step back and help nature take its course, rather than engineering a new system, we can reap the social, environmental, and economic benefits that inherently come with it.