Boats struggle to leave harbor; dredging on the horizon
BAY CITY -- Wisconsin Department of Natural Resources officials say the Bay City campground harbor and access channel has filled with so much sediment that larger boats are having a hard time getting out when water tables are low, thus limiting the use of the harbor.
The village of Bay City has requested DNR approval to dispose of sediments that are to be dredged from the Mississippi River. The sediments will be used as fill on village property, adjacent to the closed landfill located at W6778 150th Ave. in the town of Isabelle.
According to the Lake Pepin Legacy Alliance, sedimentation in Lake Pepin is a growing problem, as evidenced in the Bay City harbor. The LPLA estimates around 1 million metric tons of material (equivalent to a cubic city block) settle in Lake Pepin each year, the majority of which collects at the head of the lake.
“This is not uncommon on the Mississippi,” said DNR Water Management Specialist Mark Harings, who serves Dunn, Pepin, Pierce, St. Croix and part of Polk counties.
The sediment is mainly sand, said Wisconsin Department of Natural Resources West Central Region Hydrologist Brian Kalvelage.
“Sediments and disposal areas that meet certain environmental standards/specifications can be disposed in other areas besides landfills,” Kalvelage said. “This saves trucking costs, disposal costs, and also minimizes road traffic and pollution hauling the dredged spoils longer distances to a licensed landfill.“
Once the DNR issues the dredging permit, the village will have three years to complete the project.
“A five-day notice must be provided to the WDNR prior to start,” Harings said. “No work can occur from March 15 to May 15.”
Bay City Clerk Shawnie King said a start time for the dredging has not been pinpointed. When it happens, the mechanical dredging will use “typical excavation equipment,” such as long stick backhoes, typical dump trucks and loaders, King said.
The permit will allow for up to 10,000 cubic yards of sediment to be removed. The U.S. Army Corps of Engineers last dredged the harbor in 1965.
The project cost is still unknown, King said. It will depend on how much sediment is removed. Donations are being sought to get the project moving.
As for the material removed, it will be placed on the landfill as a “low hazard solid waste,” King said.
“It is not ‘fill’ in the normal sense of fill for building pads, etc.,” King said. “No future construction can or will take place on this material at the disposal location,”
The dredging is important to maintain recreational boat access from the harbor to the Mississippi River, King added.
“Wave action since the harbor was dredged some 50 years ago has caused the sediments to migrate and pile in front of the harbor mouth to the point that in times of low water boat access in and out of the harbor is limited to shallow draft boats,” King said.
Questions about the project can be directed to Kalvelage at 608-785-9983 or Brian.Kalvelage@Wisconsin.gov.
As for the rest of Lake Pepin, according to the Lake Pepin Legacy Alliance website, it’s partnering with Audubon Minnesota and the U.S. Army Corps of Engineers to “restore habitat, water quality and small boat navigation at the head of the lake by constructing islands and dredging backwater bays.”
A federally funded feasibility study will begin in 2017. LPLA Executive Director Rylee Main said the majority of sediment (80-90 percent) is coming from erosion in the Minnesota River Basin.
The LPLA project as a whole, which is separate from the Bay City dredging, is estimated to cost $10 million.
Solutions outlined by the LPLA include: reducing sediment by implementing conservation practices within the watershed; protecting existing shorelines and building new islands to direct flow, reduce erosion and create protected areas for migrating birds and fish; and dredging channels and bays to increase overwintering habitat for fish and provide access channels for improved navigation.
To learn more, visit lakepepinlegacyalliance.org.