Fern Hill Private School approached Conservation Halton and the Cootes to Escarpment EcoPark System in 2015 to get advice on how they could transform their already naturalized school property. We have since helped them transform the ecosystem into an oasis for birds, butterflies, pollinators, and wildlife.
In a natural system, like a forest or meadow, about fifty percent of water gets absorbed back into the ground, whereas in a built up urban environment around fifteen percent absorbs into the ground. The leftover water flows into the creeks and lake, untreated, through the municipal storm sewer system or in the form of runoff. Water running into the natural ecosystem from the urban environment often contains chemicals from asphalt, lawn fertilizers, spills, and car pollution etc. While our urban areas are growing in size and density, a number of impervious surfaces such as driveways, parking lots and rooftops grow as well. The additional impervious surfaces put a strain on the municipal storm sewer system as well as the creeks and rivers that exist within our landscape. As the climate changes, we expect to see more intense and more frequent rain events, which will aggravate the problem of run-off and overburdened storm sewer systems. City planners aren’t the only ones that need to consider impervious surfaces and runoff; other groups like private businesses, churches, and schools also need to think ahead about low impact development technologies.
Fern Hill is located on North Service Road in Burlington and has spent many years actively building its environmental programming through several initiatives, including bird banding and identification in the field studies course. The school property is nestled within an environmentally significant area and within close proximity to the Niagara Escarpment. The property also has known populations of the Mottled Duskywing Butterfly, an endangered species, bordering it. The school property is surrounded by the important headwaters of both Indian Creek and Falcon Creek.
On closer inspection, it was identified that all the precipitation falling onto the property was running off into a small storm water pond that was overrun by invasive phragmites. Phragmites were a harmful presence in the pond, and greatly affected the resilience of the pond to contain the overflow. It was the beginning of a domino effect that touched areas further outside of Fern Hill. Since the pond was not able to contain the run-off, the runoff from the property was, for the most part, bypassing the pond and being channeled directly into Indian Creek. This direct flow causes slope instability, erosion, increased flows, and degraded water quality. Indian Creek eventually flows into Hamilton Harbour and ultimately into Lake Ontario where most of the region gets its drinking water. The pond is an example of how small, unhealthy ecological features are indeed able to upset areas elsewhere, like our drinking water. It’s all connected.
We identified the need for a Low Impact Development alternative approach to the existing storm water management on the property. The project was a large undertaking and required collaboration for sourcing funding and to be executed successfully. There were many partners who contributed to the project:
- Fern Hill School
- Conservation Halton
- Cootes to Escarpment EcoPark System
- Bay Area Restoration Council
- Green Venture
- City of Burlington
- The Ministry of Environment and Climate Change
- Ministry of Natural Resources and Forestry
The final design incorporated several methods of Low Impact Development to create a “treatment-train” approach to handling the storm water runoff. The system diverts approximately 7,500 m2 of stormwater into a bioswale that then leads into two rain garden cells. A rain garden is a sunken garden designed to capture, absorb and filter stormwater. During heavy rainfalls and after seasonal snow melts, stormwater runs off surfaces such as rooftops and parking lots. This runoff collects pollutants and deposits them into streams and storm drains. By collecting stormwater and allowing it to infiltrate, rain gardens help to reduce pollution and improve the water quality of our streams and Hamilton Harbour. In addition to reducing stormwater runoff and downstream erosion and improving water quality, the garden provides food and habitat for a variety of butterflies, birds and other wildlife. The majority of the water infiltrates back into the ground as it passes through the system. The gardens are separated by an ‘eco-grid’ permeable pathway that leads to a third rain garden. A permeable pathway is a type of LID which allows water to flow through it, rather than over it, and collect in a stone reservoir where it slowly soaks into the surrounding soil. A permeable pathway reduces water pollution to local streams and the Hamilton-Burlington Harbour, thereby preventing downstream erosion and helping recharge groundwater aquifers. Underneath the top layer of gravel is a material called “ecogrid.” This is made from recycled plastic and it reinforces the pathway so you can walk on it and still allows for infiltration of water.
Smart LID design is one of many ways to help nature heal itself. The gardens are planted with pollinator and bird-friendly native species including New Jersey Tea, which is the host plant for the endangered Mottled Duskywing Butterfly. Native species are resilient and easy to maintain. A pergola was installed to serve as an outdoor classroom for the field studies program students. Interpretive signage was also installed to provide educational information on the purpose and function of the gardens. Construction of the gardens was completed in late 2016. Lastly, there are plans to eradicate the invasive phragmites from the original storm water pond and expand on the gardens and educational components of the project.
Fern Hill Private School is but one example of how the community can accomplish big things by working with nature, to take care of nature. The school has even included a weekly class for all grades in their curriculum to teach its students about the environment through nature outside their doors. By engaging and educating the youth of today we are ensuring the health of our ecosystem and that people will get to continue to enjoy nature for generations to come.
Last modified: September 5, 2017