Ice ridges form on Fish Hook Lake
By KEVIN CEDERSTROMkcederstrom@parkrapidsenterprise.com Homeowners on Fish Hook Lake are seeing more damage than normal to shoreline caused by ice heaves this year. David and Amy Andersen live on the south side of Fish Hook and ice heaves have pu...
By KEVIN CEDERSTROM
Homeowners on Fish Hook Lake are seeing more damage than normal to shoreline caused by ice heaves this year.
David and Amy Andersen live on the south side of Fish Hook and ice heaves have pushed their shoreline up three to four feet. What’s normally a level yard extending from their house to the beach now has a wall of dirt and grass with uprooted trees and a boat lift pushed back away from shore.
David Andersen said this is the first time he’s seen damage like this to his shoreline on Fish Hook.
Similar damage can be seen around Fish Hook Lake.
“This spring has been bad because of the type of winter we had,” said Doug Kingsley of the Minnesota Department of Natural Resources Fisheries office in Park Rapids. “There was no snow and a lot of swings in temperature with thawing, ice contraction and expansion.”
Ice heaving is a powerful natural force which forms along the shoreline and may cause significant damage to retaining walls, docks and boat lifts, and sometimes to cabins and houses themselves, according to the DNR.
Kingsley said these ice ridges can be a nuisance to people but are actually better for water quality by preventing runoff from going directly into the lake.
Damage to shorelines is often caused by the pushing action of an ice sheet. Cracks form in ice because of different contraction rates at the top and bottom of the ice sheet. This is especially true in years lacking an insulating snow cover, according to the DNR.
Ice cracks also develop because the edges of the ice sheet are sometimes firmly attached to the shoreline. When water rises in the cracks and freezes, the ice sheet expands slightly. When rising air temperature warms the ice, the additional expansion exerts a tremendous thrust against the shore.
Property owners are allowed to repair the damage to shoreline but must meet certain criteria with Hubbard County and the DNR.
Eric Buitenwerf, Hubbard County Environmental Services Officer, said for example, property owners who have had flat lawn for decades would be allowed to return the property to the flat conditions it was previously. Property owners should take photos of the damage before and after the repair and turn into the county.
In cases where there is a permanent ice ridge property owners are not allowed to remove unless they go through the variance process.
According to the county ordinance dealing with shoreline management, Property owners may repair damage to a shoreline from a single season of ice damage that occurred within the last 12 months when the ice ridge had been legally altered in prior years providing such work is reported to the Land Records-Environmental Services Department.
Alteration of an ice ridge in all other circumstances must be authorized by a variance pursuant to
Article XI of this Ordinance.
A number of lakes in the area, including Fish Hook, Long Lake, and parts of Big Sand have been affected by the ice ridges.
Buitenwerf said when it comes to repairing damage it’s best for property owners to wait until the frost is completely out of the ridge before doing the work.
According to information provided by the DNR, the expanding ice sheet moves soil to create ice ridges as high as five feet or more.
Alternate warming and cooling of an ice sheet causes additional pushing action.
The following information is from the DNR website regarding a permit to remove or grade soil material (ice ridge).
Minnesota rules allow for some exceptions with regard to ice ridges. An individual Public Waters Work Permit would not be required from the DNR for ice ridge removal or grading under the following conditions:
The ice ridge resulted from ice action within the last year;
The project is either exempt from local permits or is authorized by issuance of a local government permit;
Not more than 200 feet of shoreline is affected;
All ice ridge material that is composed of muck, clay or organic sediment is deposited and stabilized at an upland site above the ordinary high water level (OHWL);
All ice ridge material that is composed of sand or gravel is removed as provided above or graded to conform to the original cross-section and alignment of the lakebed, with a finished surface at or below the ordinary high water level (OHWL);
No additional excavation or replacement fill material occurs on the site;
All exposed areas are immediately stabilized as needed to prevent erosion and sedimentation; and
Local zoning officials, the Watershed District, if applicable, and the Soil and Water District are given at least seven days prior notice.