Project aims to keep river away from county road
By Janet Kubat Willette
Date Modified: 12/03/2013 2:50 PM
WELCH, Minn. — The Cannon River has been inching ever closer to County Road 7.
An aerial image shows the river's streambank erosion progression from 1938. Beau Kennedy, water planner and wetland administrator for the Goodhue County Soil and Water Conservation District, said the rate of erosion was 5.2 feet per year when he first assessed it, but that increased to 6 feet to 10 feet per year.
In 2010 and 2012, portions of the stream bank in the vicinity of Welch Ski Village eroded more than 25 feet. Kennedy calculated that 2,210 tons of total suspended solids were entering the Cannon River from the streambank. The river was continually eating away at its eight foot bank.
The flood of June 2012 brought the continued streambank erosion to the attention of several stakeholders, including Goodhue County and adjoining landowners. If nothing was done, it was feared the river would reach Goodhue County 7, an important thoroughfare.
The river does a 90 degree turn in the field across from the ski area, and it naturally wants to add length, Kennedy said.
The Goodhue SWCD applied for a grant through the Minnesota Recovers Task Force to do work on the streambank. Goodhue County Public Works is the cost-share applicant for the funds the SWCD secured for the project, Kennedy said.
The $127,500 grant requires a local match, bringing the total project cost to $170,000, Kennedy said. The local match is a nine acre buffer with an easement that will allow the county access to the river.
Work on the project started the week of Oct. 15. It was expected to wrap up last week with native grass seeding in June. A cover crop was to be sown to take the project through winter and spring.
The project had three parts, Kennedy explained. First, Flueger Construction of Red Wing installed three rock j-hooks. One j-hook is 70 feet long; the other two are 55 feet to 60 feet long. The purpose of the j-hook is to divert water with the most energy into the center of the stream and away from the bank, thus protecting the bank from erosion, he said.
Next, Flueger installed toe wood with root balls along the entire bank. The toe wood came from on site, the nearby ski village and flood plain land nearby, Kennedy said. The root balls face into the channel, providing a buffer for the earthen streambank and also providing habitat for fish, turtles and other amphibians.
The third part of the work is creating a bench — a 35 foot wide bench from stream edge back into the fields. The soil will be seeded with native grasses. In essence, the bench is a wider flood plain for the river.
"Actually implementing this practice on the streambank is a representation of the many meetings, discussions and compromises by the Minnesota Department of Natural Resources, Goodhue SWCD, Welch Ski Village, Goodhue County Public Works and other adjacent private landowners," Kennedy said.
The county public works department has taken the lead for the project, dedicating time and staff to the project, Kennedy said. The SWCD found potential funding sources, assisted with design and is helping with on-site construction management. The DNR gave input on project design.
Todd Majerus, Goodhue County Public Works highway foreman, said he was on-site every day with a crew of five or six.
The Goodhue County Sentence to Serve crew came to help with hand work.
On Nov. 7, Goodhue County Sentence to Serve crew members were on site, harvesting willows from an island in the river and ferrying them across to the other side where other crew members laid the willows on coconut fiber mats covered lightly with soil. The sandbar willows won't grow huge and fall into the river; rather they're more shrub-like and will help protect the bank.
The willows are sandwiched between what Kennedy described as soil burritos – soil wrapped in the coconut mat. The willows are like the cheese between ground beef patties.