Staging for replacement of the Sunset Lake Dam in Vicksburg started in mid-July in advance of the $3.4 million construction. Kalamazoo County Drain Commissioner Jason Wiersma said the initial tasks required mobilizing and tree-cutting.
Meanwhile, the first phase of the work will center on Prairie Street, where an existing culvert will be replaced with a new one to increase flow of the legal lake level Wiersma implemented a while back.
Motorists may have noticed distribution of detour signs near downtown Vicksburg, ready to be erected when they’re needed to protect work zones.
Wiersma said the current dam, built in 1850, does not meet state standards for a 200-year rain event, one so severe it could be anticipated just once in that period. It has clearly served its purpose for an impressive amount of time, but its current state, Wiersma noted, has been a concern since long before he took over the post more than five years ago.
The project is being funded with $2.5 million in American Rescue Plan Act funds, plus another $900,000 – which will cover the anticipated cost of the new culvert and its placement – provided by Michigan Department of Environment, Great Lakes and Energy.
Wiersma said Vicksburg will not incur any expense as a result of the dam replacement.
The new dam will be on the north side of Washington Street. Wiersma said its design is called a labyrinth weir, a stair-step style that creates a cascading effect as water flows over it. The design satisfies precautions that must be followed due to the protected status of snuffbox mussels.
“The labyrinth weir structure is so much nicer because there’s no operational component to it and its flow creates water motion beneficial to the snuffbox mussel,” Wiersma said.
He said Sunset Lake Dam is considered a high-impact dam, the only one of its kind in Kalamazoo County, he said. It will be the biggest dam replacement he has been a part of since becoming drain commissioner in January 2021.
The first step will center on creating a bypass channel, which will divert water away from its current course. The process is called “bypass pumping” and is a temporary measure. Once that is established, workers can then begin the task of creating the new dam.
He said Sunset Lake’s water level will not be affected by the construction.
Water will leave the labyrinth weir dam via a sloped channel and continue to a secondary waterfall in the same area as the current dam.
Wiersma said Sunset Lake receives its water from Gourdneck Creek. Sunset Lake water flows south under West Prairie Street into what is known by old-timers as Simpson Mill Pond. From there, the flow continues through a channel into the Washington Street culvert, over the dam and from there south as the Portage Creek. Portage Creek then flows several miles into Barton Lake, ultimately continuing to Portage Lake in Mendon Township.
The project manager is Spicer Group, while Kalamazoo-based Taplin Group LLC. is the main construction contractor. Wiersma said he is familiar with both and had no concerns about whether they would perform as expected.
“They’ve done other dam projects, and finding them and hiring them was the responsibility of my engineering firm,” he said. “They’ve done bigger dams with higher flow rates, so, we felt comfortable awarding the project to them.”
All dams come at a risk, he added. “A lot of contractors don’t want to take on dam jobs. You have to be really good at it and it’s really a niche job.”
Wiersma said he expects the project to be done in November. “We want to make sure the new grass is growing well and all that good stuff, so it’s going to be later in the year.”
