There are several sound approaches to replacing a poorly functioning, undersized, fish-blocking culvert. The first step is to remove the old structure.
Sometimes nature gives TU and others who frequently tackle that kind of work a headstart, with flood waters blowing out roads and starting the demolition process.
When high flows damaged one bad culvert road crossing on Crossett Creek in Northern Wisconsin, there was a chance to start from scratch.
“My team identified the location in 2020,” said Chris Collier, TU Great Lakes Program Manager. “At the time it was three culverts and actively failing.”
But fully replacing culverts takes planning and time — luxuries not always available when there is urgency to repair a damaged, busy road. Full replacements are also not inexpensive, and those costs can be especially difficult for rural localities with limited budgets to absorb.
“These towns will go slack jawed at the cost,” Collier said.
That means that towns and counties responsible for problematic crossings sometimes try more immediate, budget-friendly fixes rather than outright replacements.
In the case of the Crossett Creek project, that meant trying to account for high flows by adding two additional culverts.
“It was now a five-culvert monstrosity,” Collier said. “And it still failed the next year, and the year after that.”
Collier, along with Florence County and the town of Aurora, got to work on a permanent solution, one of many that TU has undertaken in the county recently honored as a Trout Unlimited Conservation Town.
“It was probably the worst culvert we’ve ever repaired,” Collier said. “But we were able to collaborate and get it done.”
The project not only gave the creek plenty of room to flow, protecting the road above, but also reconnected miles of coldwater habitat by allowing trout and other stream dwellers to move freely both upstream and downstream.
Crossett Creek is a tributary of the Menominee River. During the heat of summer the river can get too warm for trout, so Crossett Creek’s cooler waters provide crucial cold water refugia. There’s a lake in the upper part of the system that also holds trout.
“It’s the same kind of problem we see across the state,” Collier said. “You’ve got these tributaries that might not be the most fishable water, but they are really important for spawning and coldwater refuge, and fish from the larger rivers can’t get into them.
“We’re depressing trout numbers in the fishable water because the fish can’t get into these tributaries.”
The project on Crossett Creek cost a total of $180,000.
Funding came from a variety of sources, including the town of Aurora, the Florence County Land Conservation Department, a Fish and Wildlife Service Fish Passage Grant, the Fund for Lake Michigan, a foundation that supports TU’s work in the region, and a grant from TC Energy.
“It was a really good example of pulling together several modest pots of funding to make it happen,” Collier said. “ And in the new culvert’s first spring it was able to withstand another major flood and keep the road open.”