It started with a meeting between members of the Charlotte Congregational Church and the Lewis Creek Association, said Lewis Creek Association Program Coordinator Krista Hoffsis. People were looking for a way to help Lake Champlain, to keep pollution out. Now, through the Lewis Creek Association’s Ahead of the Storm project, a series of existing and planned demonstration sites in Charlotte, Hinesburg, and Shelburne will both play this role and provide examples for the public of how to handle stormwater and mitigate its damaging effects as it rushes across the fields and streets of the Champlain Valley.
At Charlotte’s Mack Farm, a swale runs along the side of Thompson’s Point Road. The large ditch, completed this past September, used to be V-shaped, but it’s now U-shaped, with a flat base. Vegetation has begun to grow in the swale, which drains the surrounding 17 acres. Under the vegetation, explained Hoffsis, is gravel and cobble, which filter water. The swale stands ready to handle the influx of water that a 100-year storm event could produce.
Downhill from here is a large culvert with gravel on top to provide filtering, even if water runs above the culvert’s 10-year storm capacity. And finally, downstream from that, a gravel and cobble-lined ditch, containing a series of raised gravel beds and check dams, will create pools to catch water as it heads downstream toward Thorpe Brook, which drains into nearby Lake Champlain.
The goal of these complementary cobble and vegetated components, said Hoffsis, is to allow stormwater to “soak in, spread out, and slow down” on its journey toward Lake Champlain. “Those are the three things that we want, to be able to control our water and reduce pollution.”
Demonstration sites, all in the LaPlatte River watershed, are selected based on location criteria: a large drainage area, near waterways. Mack Farm is one of a couple of completed demonstration sites—another is in Shelburne’s Brook Lane neighborhood—and a total of 14 are anticipated, said Hoffsis. The engineering and planning are complete; now it’s just a matter of lining up funds. The Mack Farm site was funded through two Better Back Road grants, with funds also coming from the Town of Charlotte. The materials from these projects, including site and cost analyses, will eventually be available online.
“The hope is to inspire people to have the tools to do this themselves,” said Hoffsis, though of course scaled to people’s property and needs. “Any small nugget that someone could take away from this is great—anything that someone could do on their own land.”
Hoffsis noted that three to five additional demonstration sites may hopefully be completed in the next year or two. “We’re trying to do the most good with the least amount of space and resources,” she said.