written by John Custodio
Published on Dec 13, 2022
FAIRFAX — A drainage ditch and water runoff project in Fairfax is going swimmingly, according to Kent Henderson, chair of the Friends of Northern Lake Champlain.
The group is in charge of the project a quarter of a mile from Exit 18 on Interstate 89 that seeks to drain water runoff and catch phosphorus from Route 7 and 104A before the Deer Brook.
The gully drains water from nine acres on Route 104A before flowing into the Deer Brook, which flows into Arrowhead Mountain Lake. Photo from John Custodio.
In the 1970s, Henderson said the culvert and pipe drainage system were up to code and followed typical practice, but it resulted in the bank being carved away from the amount and speed of water running over it.
“It was forcing it into a 9-inch culvert, and on a heavy rain event, it would shoot the water out 20 or 30 feet,” Henderson said. “It was condensing it down, putting it under a lot of pressure and it would add a ton of velocity and it caused major erosion in that gully.”
Now, water will run through a 40-inch culvert that will allow for slower, steadier drainage to lessen dramatic erosion.
Henderson said Stone Environmental designed the project, allowing the area to drain up to nine acres of land on a roadway that gets large amounts of traffic.
To decide what projects are funded and get attention, the FNLC crunches the numbers to see what projects will impact the largest amount of phosphorus in the lake for the least amount of money.
Generally, this results in a lot of projects on farms and working with farm owners, but Henderson said the blame can’t be entirely pushed onto farm owners as vehicles and roadway runoff produce a lot of pollutants as well.
“Everybody that drives a car, eats food, or drives on these roads is contributing,” Henderson said. “One way or another, we’re all contributing. Through demonstrations like this, people can see they can make a difference.”
Besides large projects, there are some smaller projects that landowners can work with the FNLC to accomplish or get advice on.
Near the gully project, a landowner worked with the FNLC to build a swale to capture runoff before it hit the Deer Brook. A swale is a shallow ditch with a rise built immediately behind it, allowing for water to pool, lose velocity and allow for chemicals to be naturally filtered out by plants before running into the brook.
The swale will physically catch the water running off of the parking lot, and native plants will capture phosphorus before it hits the Deer Brook. Photo from John Custodio.
At the gully’s swale, Henderson said FNLC wants native grasses and shallow rooted shrubs to grow to capture and use the phosphorus from runoff so it doesn’t all reach the brook and contribute to Lake Champlain’s levels.
The gully project was funded by a grant from the Vermont Department of Environmental Conservation and is costing $400,000.
The project so far has stabilized the bank and gully to prevent major erosion that could impact local businesses, installing a deep manhole and a deep sump catch basin. The project has also expanded the pipes that move water out into the gully, lowering water pressure and velocity once it exits the pipe.
In the gully, stones were placed in to prevent more gully erosion and to allow for step pools where water will collect and be slowed along with allowing for more natural chemical filtering.
Where the project stops, fallen trees and other plants start to fill the gully. But Henderson said that is a good thing, as that is how the runoff will be further slowed and filtered before joining the Deer Brook and eventually flowing into Lake Champlain.
He/Him | John is a staff reporter covering Enosburg, Montgomery and northern Franklin County, along with the Missisquoi Valley and Franklin Northeast school districts.