School Green Stormwater Infrastructure
Green Stormwater Infrastructure (GSI) is a nature-based solution to stormwater runoff. These practices use plants and simple infrastructure to manage stormwater runoff by slowing it, spreading it, sinking it or storing it.
Georgia Elementary rain barrel plan. Courtesy of Fitzgerald Environmental Associates.
With funding from the Lake Champlain Basin Program in 2019, FNLC managed the implementation of green stormwater infrastructure (GSI) projects at three Franklin County schools. They include a rain garden at BFA-Fairfax, and in-ditch sediment settling forebay at Alburgh Community Education Center, and a rain barrel collection system at Georgia Elementary and Middle School. These functioning practices will be used in STEM education as examples of green stormwater infrastructure and how they provide water quality benefits.
The goal of these projects are to reduce the amount of phosphorus and pollutants that are transported into natural waterways via stormwater runoff, and use area schools to educate and drive early adopters in the community. We hope that projects like these will help schools and other municipal properties become early adopters of GSI to ease the transition of the forthcoming “3 acre rule”, which will require a stormwater permit for all properties with 3 or more acres of impervious surface.
The rain barrels at Georgia Elementary and Middle School were constructed in 2019, with a grant from the Lake Champlain Basin Program. Based on the analysis by Fitzgerald Consulting Associates, six rain barrels that hold 55 gallons of water were installed to collect runoff from 900 square feet of rooftop area. The collected rainwater is intended to be used on the garden bed next to the rain barrel collection system.
What is a rain barrel?
Construction and painting of the Georgia rain barrels.
Rain barrels capture water from roofs and store it for later use on lawns, gardens, indoor plants, or other activities that use water, like car washing. When too much rain falls onto hard surfaces like roofs, driveways, and roads, the water can’t soak into the ground and flooding can occur.
The water can also pick up pollutants such as bacteria and chemicals as it flows from hard surfaces, which eventually make their way into rivers and lakes. Storing the water from roofs in rain barrels reduces the amount of water that flows from your property into storm drains and waterways, reducing pollution in our rivers and lakes. Rain barrels also reduce erosion. Rather than letting the water from your roof gutters carve away soil, rain barrels can collect most of the excess water, minimizing erosion around your house.
How do rain barrels work?
Usually, a rain barrel is composed of a 55 gallon drum, a vinyl hose and/or spigot, and overflow spout, and screen grate to keep debris and insects out. The rain barrel will collect and store water from rainstorms that would otherwise be lost to runoff, and potentially cause flooding and erosion. The stored rainwater can then be used for activities that would otherwise use potable water.
A rain barrel is relatively simple and inexpensive to construct and can sit conveniently under any residential gutter downspout.
Some tips for using rain barrels:
Do not use collected water for drinking, cooking or bathing.
Keep the lid secure so children and pets cannot fall in and make sure that all other openings are secured to help prevent mosquitoes from entering the barrel.
The atrium gate should prevent most mosquitoes but eggs could still fall through so for added mosquito prevention add a tablespoon of vegetable oil to the water every season or try a mosquito dunk that kills mosquito eggs but is non toxic to plants and animals.
When using the overflow valve, make sure water drains away from structures and does not flow onto pavement, sidewalks, or neighboring properties.
Disconnect the barrel from the downspout during winter months to avoid the formation of damaging ice in the barrel.
Paint or decorate your rain barrel to make it a distinct part of your yard or garden!
What can you use the water for?
Collected rain water is useful in the summer and periods of drought to…
Water lawns, gardens, trees, and potted plants
Wash your car and windows
Clean outdoor items
Top-off swimming pools
They provide an ample supply of free "soft water" to homeowners, containing no chlorine, lime or calcium making it ideal for gardens, flower pots, and car or window washing. A rain barrel will save most homeowners about 1,300 gallons of water during the peak summer months. Saving water not only helps protect the environment, it saves you money and energy, and decreases demand for treated tap water. Therefore, a rain barrel is an easy way for you to have a free consistent supply of clean, fresh water for outdoor use.
Where can you get a rain barrel system?
Ready-made rain barrels can be purchased from a number of companies, including hardware stores and garden supply stores. In addition, local governments sometimes offer them for a reduced price as part of their environmental education programs.
Mill River Brewing Rain Barrel Auction in 2019.
Interested in making you own?
Click the button for a brochure to teach you how to make your own rain barrel at home!
Photo 1. Cassi Carpio planting cardinal flower plugs at
BFA-Fairfax Rain Garden.
Photo 2. Planting in progress at the rain garden.
Photo 3. BFA Fairfax rain garden plan. Courtesy of Fitzgerald Environmental Associates.
Photo 4. Conceptual design cross section of the BFA rain garden, courtesy of Fitzgerald Environmental Associates.
The rain garden at Bellows Free Academy in Fairfax was constructed in 2019, with a grant from the Lake Champlain Basin Program. The rain garden was designed by Fitzgerald Environmental Associates to absorb and treat water running off the school roof and parking lot, while adding aesthetic qualities to the school’s lawn.
What is a Rain Garden?
A rain garden is a bowl‐shaped garden planted with a variety of deep-rooted native flowers, shrubs and grasses, that is designed to capture and absorb rainfall and snowmelt, also known as stormwater. When water falls on hard surfaces like parking lots, roofs, compacted soils, and roads, it begins to accumulate or run off those surfaces. These are called impervious surfaces, because the water can’t be absorbed. In contrast, pervious surfaces, like soil, grass, planted areas, and forests, absorb water when it rains deep below the ground.
Photo. Example of water flow over pervious vs. impervious surfaces
Stormwater becomes a problem because it collects pollutants such as particles of dirt, fertilizer, chemicals, oil, garbage, and bacteria as it runs off the land. The polluted water then flows to nearby lakes or rivers either directly or through a storm drain. The US EPA estimates that pollutants carried by rainwater runoff account for 70% of all water pollution. Stormwater also causes increased flooding and erosion if it can’t be absorbed into the ground.
Alternatively, rain gardens collect the stormwater runoff, allowing the water to be filtered by plants and absorb into the soil, which helps recharge groundwater aquifers. Plants in rain gardens have deep roots systems, which stabilize the soil below the ground and encourage water infiltration. Compared to a conventional lawn, rain gardens allow for 30% more water to soak into the ground.
Photo. Example of root depths of different plants
How do rain gardens work?
A rain garden is not a regular garden. Nor is it a pond or a wetland. Conversely, a rain garden is dry most of the time. It typically holds water only during and after a rainstorm. Because rain gardens are designed to drain within 12-48 hours, they prevent the breeding of mosquitoes.
Rain gardens are generally constructed on the downside of a slope on your property and collect water runoff from the lawn, roof and/or the driveway. Once water collects in the rain garden, infiltration may take up to 48 hours after a major rainfall. Also, rain gardens incorporate native vegetation; therefore, no fertilizer is needed and after the first year, maintenance is usually minimal. The native plants attract beneficial birds, butterflies, and insects, and are an aesthetically pleasing addition to your property.
Want to build your own rain garden?
Check out this step-by-step guide from the Rain Garden Alliance on designing and building a rain garden on your property:
Or watch this video series from the Maryland Sea Grant Extension on how to install a rain garden:
Alburgh Community School
The sediment settling forebay at the Alburgh Community Education Center was completed in 2020, with a grant from the Lake Champlain Basin Program. It was designed by Fitzgerald Environmental Associates to slow the stormwater that runs off the school parking lot and allow the sediment particles in the stormwater runoff to settle out before reaching a grass swale. The rock-lined forebay, or basin, allows coarse sediment particles to settle out, while the grass swale absorbs the stormwater.
Photo 1. Alburgh Community School sediment settling forebay plan Courtesy of Fitzgerald Environmental Associates. Photo 2. Rock lined sediment settling forebay. Photo 3. Planting the grass swale.
What is a Sediment Forebay?
All green stormwater best management practices (BMPs) are designed to manage runoff by slowing the water, spreading it out, absorbing the water, and/or storing it for future use. Many BMPs perform a combination of these functions.
A sediment forebay is an excavated pit designed to slow and temporarily store incoming stormwater runoff to allow suspended solids to settle out. The suspended solids, or sediment, sink to the bottom of the pit when stormwater is collected. Sediment forebays are usually used to pre-treat stormwater before it eventually flows into another BMP. They are a relatively inexpensive method that, with proper maintenance, can slow incoming stormwater runoff and settle out sediments.
Why is Sediment Pollution a Problem?
Sediment is the loose sand, clay, silt and other soil particles that make the water in rivers and lakes appear brown and cloudy. Sediment can come from soil erosion or from the decomposition of plants and animals. However, the most concentrated sediment releases come from construction activities.
Sediment particles are often detached from the land by rain and are then transported into rivers and lakes by stormwater. Any soil that is not protected from rainfall or runoff may be vulnerable to erosion and become a source of sediment pollution.
Sediment entering stormwater degrades the quality of water for drinking, wildlife and the land surrounding streams in the following ways:
Sediment fills up storm drains and catch basins that carry water away from roads and homes, which increases the potential for flooding.
Water polluted with sediment becomes cloudy, preventing animals from seeing food.
Murky water prevents natural vegetation from growing in water.
Sediment in stream beds disrupts the natural food chain by destroying the habitat where the smallest stream organisms live and causing massive declines in fish populations.
Sediment increases the cost of treating drinking water and can result in odor and taste problems.
Sediment can clog fish gills, reducing resistance to disease, lowering growth rates, and affecting fish egg and larvae development.
Nutrients like Phosphorus and Nitrogen transported by sediment can activate blue-green algae that release toxins and can make humans and animals sick.
Sediment deposits in rivers can alter the flow of water and reduce water depth, which makes navigation and recreational use more difficult.
For these reasons, the EPA lists sediment as the most common pollutant in rivers, streams, lakes and reservoirs in the US.
Sediment also poses a greater water quality risk than just soil particles alone because it often carries other pollutants such as nutrients, heavy metals, organic chemicals, bacteria, and other pathogens along with it. These pollutants originate from sources such as agriculture, industrial waste, mines, and urban contaminants.
Conceptual design cross section of the Alburgh Sediment Settling Forebay courtesy of Fitzgerald Environmental Associates.