Hinesburg replaces old stormwater system with a Bioretention System to Improve Water Quality in the LaPlatte River
At the beginning of October 2014, the Lewis Creek Association and the Town of Hinesburg constructed a new stormwater treatment system at the intersection of Vermont Route 116 and Silver Street. With funds from the Vermont Department of Environmental Conservation Ecosystem Restoration Program (ERP), the partners replaced existing “gray” infrastructure (three stormwater culverts that emptied directly into the river) with green stormwater infrastructure (GSI). GSI uses natural materials and processes to lessen the impact of the built environment on waterways.
The Silver Street bioretention system improves water quality by filtering pollutants that run-off from 7 impervious acres within the town. Water flows through beds of 1,350 native plants and shrubs growing in a shallow depression lined with permeable soils. By virtue of its careful construction, it also tempers the rush of water from storms by capturing it and allowing it to infiltrate into the ground. When a really large storm happens, a vegetated swale will allow excess water to slowly flow toward the LaPlatte River. Together, the filtration and infiltration promoting functions of the system provide a more natural flow of stormwater into the LaPlatte River.
The well-chosen array of plants for this project shows that form can match function when it comes to GSI. As the landscaping matures over the next two years, the flowering plants and attractive shrubs will become a public garden whose beauty matches its technical function. Its’ highly visible public location invites the public to experience stormwater management in an entirely new way. Maintenance of the system is straightforward, and is more akin to maintaining a garden than traditional stormwater infrastructure.
As GSI systems become more common features on the Vermont landscape, their aesthetic value and functionality will help our waterways be more resilient to large storm events.