We hope you enjoy this abbreviated version of the
Serving Frankenmuth Since 1906
Vol. 114 No. 22 - In our 114th year!
Wednesday, December 4, 2019
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PAIGE WIGREN ... from the Alpena Fish and Wildlife Conservation Office - Detroit River Substation holds the only northern pike that was recaptured upstream of the Frankenmuth rock ramp on the Cass River.
USFWS report indicates Cass River fish passage is working
When the Cass River Dam at Frankenmuth was removed five years ago, it was a project necessitated by its aging infrastructure.
However, the project was engineered as such to not only hold back water, but to increase the tributary’s game fishing experience.
The United States Fish and Wildlife Service (USFWS) recently released its final report in October, chronicling the evaluation of the fish passage or rock ramp in Frankenmuth. Area residents will recall the rock ramp project was completed in fall 2014 and there were several years of pre-dam removal and post-dam removal analysis done to evaluate its effectiveness.
“I think that you will be pleased with the results, as the study indicates that all target species have the ability to pass the structure, providing them with access to important spawning areas for the first time in more than 150 years,” said Michael Kelly, director of the Great Lakes Office of the Saginaw Bay Watershed Initiative Network (WIN) and The Conservation Fund. “There are obviously social and economic benefits as well that are not part of the study, including new opportunities for recreational use of the river now that the dam has been removed, as well as additional opportunities for fishing.”
USFWS’s Justin Chiotti led the work on the river the past 3-4 years, along with colleagues Paige Wigren (USGS), Joe Leonardi (MDNR – retired) and Jim Boase (USFWS).
The Cass River is 80 miles long and flows through Sanilac, Saginaw and Tuscola counties and is part of the Saginaw Bay watershed. The Cass River begins in Tuscola County and flows westerly to its confluence with the Saginaw River, which flows into Saginaw Bay and Lake Huron.
Since the construction of the rock ramp, 17 fish species not previously detected upstream have been captured, including eight freshwater drum, 11 walleye, two gizzard shad, eight flathead catfish and two round goby. Over the past three years, 2,604 fish have been tagged downstream of the rock ramp. A total of 29 of these fish were recaptured upstream during electrofishing assessments or by anglers. Overall, the Cass River supports over 70 species of fish
"Based on the mean monthly discharge of the Cass River during April and May, the data suggests that white and redhorse suckers can move past the rock ramp during normal discharge years,” Chiotti said.
All fish species tagged were captured upstream of the rock ramp. This includes redhorse suckers, white suckers, northern pike, walleye and smallmouth bass.
“This proves that all of these species can navigate the rock ramp, however, it is unknown under what flow conditions,” Chiotti pointed out. “While full dam removal likely would have resulted in greater fish passage, the rock ramp maintained the impounded area, while allowing target fish species access to upstream habitat.”
The original dam was built in 1848 and supported a grain mill. Originally made of earth and stone, it was later modified with wood and later concrete. The dam measured 13 feet in height and was 235 feet in width.
The total demolition and construction cost for the dam was $3.5 million. The federally funded Great Lakes Restoration Initiative provided 65 percent of the project costs and Frankenmuth funded the balance with help of local businesses, charitable foundation and the Downtown Development Authority (DDA). Additionally, Frankenmuth received grant funding from the USFWS and WIN.
Since Frankenmuth has the Bavarian Belle paddleboat and the Frankenmuth FunShips upstream, the plan was to maintain the upstream water levels. The goal of the Frankenmuth rock ramp was to maintain historical water levels upstream of the former dam, while allowing fish access to an additional 25 miles of habitat upstream.
The practice of using rock ramps to replace unwanted dams and increase fish passage is fairly new in Michigan. There are only three others installed over recent years, including the River Raisin in Monroe, the Chippewa River in Mount Pleasant and the Shiawassee River in Chesaning.
Locally, the 2016-2018 post-assessment monitoring was handled by the project partners, including the U.S. Army Corps of Engineers, Central Michigan University, City of Frankenmuth, Michigan Department of Natural Resources and USFWS.
Redhorse suckers, smallmouth bass and white suckers were the dominate species captured upstream during the both pre- and post-assessments.
New species detected downstream in 2017 included blacknose shiner, goldfish, rosyface shiner, yellow bullhead and spotfin shiner. In 2018, longear sunfish and white crappie were detected. Nineteen new species were detected upstream, 2016-18, with central stoneroller and round goby new on the list in 2018.
Chiotti also pointed out that successful fish passage upstream of the rock ramp depends largely on water velocity and discharge volumes. A U.S. Geological Survey gauging station is located approximately 656 yards downstream of the rock ramp.