Less maintenance, less danger and fewer negative impacts on natural flora and fauna are all among the reasons it might be past dam time.
Instead, the Minnesota Department of Natural Resources is helping to fund two “rock arch rapids” in the Cannon River, which are considered safer for both humans and fish than the aging dams they’ll replace. The funds come from the Get Out MORE (Modernize Outdoor Recreation Experiences) grants.
The Schmidtke Dam in Morristown, also known as the Lower Sakatah Lake Dam, and the Gorman Lake Dam in Le Center are the two dams up for replacement. Minnesota Department of Natural Resources Restoration Amanda Hillman-Roberts said the project, which also includes replacement of the Dodd Road Culvert, was identified as a “priority project package” after the DNR received proposals for the initiative.
“Projects were selected for funding based on various criteria including readiness, ecological benefit, timing and technical feasibility,” she said.
More information will be made available at a community meeting, where civil engineers from Bolton & Menk will present the design concepts and booths will be set up for folks to learn more from specific organizations.
Rock arch rapids are a simple design, where large stones are placed into multiple descending rows with pools of water between, and fish are able to pass through the cracks between them.
It can still manage heavy flows, maintains river connectivity, restores natural habitat and river ecosystems and can even allow for recreational opportunities like kayaking and fishing.
Both the dams are “ripe” for the transition to rock arch rapids, said Clean River Partners Conservation Program Manager Anna Holman. The Lower Sakatah Lake Dam was built in 1938, and the Gorman Lake Dam was built in 1936.
“These dams neither generate power nor supply drinking water,” she said. “These dams are low-head dams which pose safety concerns and are often referred to as ‘drowning machines’ because the water spilling over the dam creates a roller at the base of the dam and can trap swimmers, boaters and kayakers, even those wearing a life jacket.”
She said reconstruction will open 23 miles of stream for fish passage. After implementing rock arch rapids, the natural flow of the river is restored.
This is because a traditional dam turns a river into a “static reservoir,” disrupting natural ecosystems, biodiversity and prevents fish from reaching their natural spawning areas. This even can hurt water quality by preventing mussels from riding fish upstream.
It might surprise some to know how quickly a river can bounce back after being disrupted for nearly a century. In one famous case, native salmon swam across states after removal of the Klamath River’s J.C. Boyle Dam just two months prior.
“Rivers are resilient and the positive effects can be seen relatively quickly,” Holman said. “According to MN DNR, they’ve seen fish migrating through rock arch rapids before the construction equipment leaves the site.”
Hillman-Roberts said the DNR has conducted its own studies on the ecological impacts of “barrier dams” blocking fish migration. For example, one study she cited found 37% of the fish species downstream from a barrier dam were not found upstream.
But 19 of the 32 dams studied by the DNR have since been replaced with rock arch rapids, which she said saw a similarly speedy rebound in upstream migration patterns.
“On average 65% of the missing species have returned to the upstream watershed since the barrier was removed,” she said. “Many of those species returned rather quickly as was the case with the Minnesota Falls dam removal on the Minnesota River. Anglers began reporting catching flathead catfish and paddlefish (species missing above the dam prior to removal) in Granite Falls (upstream of the project) the summer following the removal of the dam.”
Holman said construction is likely to begin in winter 2026, and the projects are proposed to be complete by summer 2027.
IF YOU GO
The open house is 6-7:30 p.m. Feb. 20 at 320 S Plut Ave. in Le Center, the 4-H Family Center, where Bolton & Menk will present the concepts. Go to www.CleanRiverPartners.org/FishPassage to sign up for periodic updates on the project.
After the presentation, folks can visit booths for the Gorman Lake Dam/Culvert, Lower Sakatah Lake Dam, Clean River Partners and Waterville Area Fisheries to learn more and ask questions.
If you have a question you’d like the engineers to address in their presentation, please register at: www.CleanRiverPartners.org/events/fish-passage-open-house. There is a space on the form to enter your question.