By LeAnn R. Ralph
COLFAX — For many years, the Red Cedar River has been chipping away at the bank standing between the river and the Colfax wastewater treatment lagoons.
The erosion has progressed to the point now where it is easy to imagine that one of the lagoons could wash out into the river.
The Colfax Village Board took the first step toward possibly repairing the riverbank at the August 25 meeting by approving a resolution to the U.S. Army Corps of Engineers.
The resolution will activate a process to verify if the site by the wastewater treatment lagoons is eligible for an Emergency Bank Protection grant, said Ron Verdon, president of the Tainter Menomin Lake Improvement Association.
Verdon presented the TMLIA’s erosion and habitat assessment report at a special meeting prior to the village board meeting.
The erosion and habitat project report will provide essential scientific information necessary to help with applying for a grant, Verdon said.
TMLIA received a lake planning grant to help pay for the report, which was completed by Inter-fluve, Inc. in conjunction with a variety of partners, including the Wisconsin Department of Natural Resources, Dunn County Land Conservation, the U.S. Army Corps of Engineers and UW-Extension.
More than 60 erosion sites have been identified along the Red Cedar River, in addition to the eroding banks by the Colfax wastewater treatment lagoons and the Colfax school district, from the Barron County line down to Tainter Lake.
Fixing the erosion sites to slow down sediment entering the Red Cedar River and Tainter Lake could accomplish two goals: reducing the amount of phosphorus that fuels algae blooms and removing sediment that is causing the delta at Champney Park to advance by 35 feet per year, Verdon said.
According to the executive summary of the report, “Because phosphorus is largely transported attached to fine sediment, and because the Red Cedar River is delivering relatively large volumes of sediment to (Tainter Lake), limiting upstream erosion could potentially decrease both the nutrient and sediment inputs. By reducing erosion at critical sites along the river, they hope to effectively address both impacts. This study aims to identify and quantify erosion issues along the Red Cedar River upstream of Tainter Lake and identify potential treatment options. In part, it builds on an initial bank erosion survey completed by the Dunn County Land Conservation Division (2006).”
The rate of sedimentation at Champney Park is accelerating.
At first, the delta was advancing ten feet per year, then 19 feet per year, and now it is up to 35 feet per year, Verdon said.
“Champney Park is no longer a boat landing,” he said.
The study covers 30.32 miles of the Red Cedar River, Verdon noted.
Before the erosion sites can be repaired, a thorough understanding of the river is necessary so that repairing one erosion site does not cause problems farther downstream, he said.
Dale Styer, who owns land south of the wastewater treatment lagoons, and Mark Mosey, the biology teacher at Colfax High School, provided valuable information for the study, Verdon said.
The study includes a map that documents the shifting of the river channel since 1938.
The northern part of the Red Cedar River, toward the Barron County line, has not meandered much in the last 76 years, Verdon said.
From Twenty-two Mile Ford to Lake Tainter, the river “has moved dramatically. It is remarkable to see where the river has been,” he said.
Whole sections of the river that existed in 1938 now no longer have any water because the channel has moved so much, Verdon said.
An aerial map of that section of the river shows other “meander scars” where the river existed hundreds or thousands of years ago.
A particularly sharp gully by the wastewater lagoons that opened up in the bank following the eight-inch rainstorm in 2010 has now loosened a fence post there, Verdon said.
The gully is not that far from the lagoon, and it’s possible to imagine the lagoon eventually washing out into the river, he said.
At the school district site, Mosey said at one time, there were three rows of trees that had been planted above the river, but now only one tree remains. The rest have washed out into the river, Verdon said.
The bank at the school district erosion site is 50 feet high, he said.
The Emergency Bank Protection grant would require the village to provide easements and right-of-way for the repair work, Verdon said.
The grant would also require the village to maintain the repair work, he said.
Repair work would include planting vegetation and riverbank stabilization using riprap, rock or log barbs, log cribwalls, floodplain bench construction and toe scour protection.
Carey Davis, village trustee, wondered how much maintenance would be involved.
Inter-fluve has done riverbank repair work around the world and is very experienced. The maintenance would be minimal, Verdon said.
The grant would cover up to $1.5 million in repair work, and the village would be responsible for all costs above $1.5 million, he said.
Verdon said he doubted that the repair work by the wastewater treatment lagoons would come anywhere close to $1.5 million.
Colfax also would have to provide 35 percent of the project cost, with 5 percent in cash, Verdon said.
The good news is that the village most likely could make an in-kind contribution for the 30 percent with volunteer labor, he said.
From conversations that he has had with representatives for the Army Corps of Engineers, Colfax would be an appropriate recipient of the grant, Verdon said.
Submitting the resolution to the Army Corps of Engineers does not commit the village to any financial obligation, he said.
The resolution merely activates a process to verify if the site is eligible, Verdon said.
The prospect of completing bank stabilization projects along the Red Cedar is “tremendously exciting and a tremendous opportunity,” he said.
TMLIA “would love to see a couple of projects move forward,” Verdon said, adding that the Colfax lagoon site could serve as an educational site for others along the river and as a springboard for the other nearly 60 sites.
Members of TMLIA are available to assist the Village of Colfax in any way that they can, Verdon said.
Several years ago, the Colfax Village Board looked into stabilizing the river bank by the wastewater lagoons but was told there were no grants available and that the cost could be in range of a half million dollars or more.
The TMLIA erosion and habitat assessment report and the U.S. Army Corps of Engineers have offered a path forward.
“It is not an option not to do anything (considering) the severity of the erosion. The (wastewater) treatment plant is a priority for the village,” said Scott Gunnufson, village president.
Gunnufson also wondered if TMLIA had talked about dredging Champney Park.
Dredging Champney Park was discussed during the development of the report, and those involved decided it would not do any good to dredge until the erosion sites are repaired upstream, Verdon said.
The report notes that one of the worst erosion sites on the Red Cedar River is at Dobbs Landing and that the erosion could have been prevented by having a buffer instead of planting row crops that extended to the edge of the bank.
Later on in the regular meeting, the Colfax Village Board unanimously approved the resolution for Emergency Bank Protection that will be sent to the U.S. Army Corps of Engineers.
Jackie Ponto, village administrator-clerk-treasurer, will send three copies of the resolution to the U.S. Army Corps of Engineers district office in St. Paul.