After three years of planning, the Franklin County Natural Resources Conservation District is moving forward with the removal of the Johnson Mill Dam in Bakersfield.
The dam, which was once used for a lumber mill, was originally constructed in the early 1800s, but since its abandonment has acted as a barrier to the natural progression of the stream it blocks, said Brodie Haenke, Conservation Specialist for the FCNRCD.
"(Old and unmaintained dams) are static barriers to dynamic rivers," he said.
The removal of the dam is the culmination of a long and extensive process. The district has worked with multiple federal and state partners, the Army Corps of Engineers and the Vermont Department of Environmental Conservation's Stream and Wetlands Program, Haenke said.
The district also worked with cultural resources such as the University of Vermont's Consulting Archaeology Program to generate reports on the historical significance of the dam site.
"It's been exciting to work on a project as complicated as this one is," he said. "It is by far the most complicated project I've ever worked on."
Haenke first got the idea for the removal of the dam when he was an AmeriCorps member, serving the conservation district, he said.
Haenke attended a statewide gathering with folks who work with watersheds and began learning about dam removals happening on the east coast.
"I was curious to know if there was the same opportunity in Franklin County," he said. "I worked with the Vermont Natural Resources Council and went through a priority list of dams that had been generated by the Nature Conservancy."
"The Johnson Mill was one of the dams in Franklin County that came up high on their list," he said.
Why dam removal is important
There are many old dams in Vermont and across the Northeast that, like the Johnson Mill Dam, are no longer being used.
"When they're not being maintained and they are no longer serving a useful purpose you should consider the negative impacts that they have on that river system," Haenke said.
Old and unmaintained dams can have an array of impacts on an environment, affecting fish passage as well as water temperature, Haenke said.
The dams prevent Brook trout from moving upstream and downstream. This prevents the trout from reaching the highest quality water in the upper reaches of the watershed.
These dams also increase the temperature of the water by having the stagnant water sit in an uncovered area. Once the warmed up water spills over the dam and flows downstream, it can be potentially harmful for a lot of aquatic species.
In addition, once a dam has not been maintained properly a breach is imminent.
"If a dam owner does not actively seek to remove it, Mother Nature will take it out for them," Haenke said.
One of the goals of any dam removal project is to remove it before there is a sudden failure that will send silt and water downstream that could potentially harm infrastructure.
The dam had been failing slowly over time, Haenke said. But during a storm Halloween of 2019, the dam breached when an old stoplog channel failed. The water in the dam dropped around seven feet and sent anywhere from 1,500 to 2,000 cubic yards of sediment downstream.
With the sediment comes phosphorus and other nutrients that now flow into Lake Champlain, Haenke said.
The district is hoping to break ground on the dam mid-August, starting with stream bank stabilization upstream and then using excavation equipment to take the dam apart piece by piece.
The sediment from behind the dam will be taken to a nearby farm where it will be spread into a hay field and turned into crops. The concrete will be broken down and used for a new construction project, Haenke said.
This coming Friday Haenke will be leaving his position on the Franklin County team a few weeks before the project's completion.
Haenke has been spearheading the project for three years and will be leaving it in the hands of District Manager Lauren Weston, he said.