(FOX 9) - This past winter was especially rough on Minnesota’s shorelines.
You’d think those giant boulders would help prevent shore erosion, but, according to one expert, they actually do just the opposite
When Bob Martsching visits his lakeside property in the spring, he gets just a little uneasy as he approaches.
“You’re just anxious when you drive up because you’re like, ‘how much has it heaved so far?’” he said.
In fact, Martsching said it was the worst he’s ever seen. The problem can even be seen on lakes all across Minnesota.
“It’s the worst year I’ve seen in 20 years,” said Joe Palumbo of The Lakeshore Guys.
It all started with higher than normal water levels. In a time-lapse video, you can see the ice move, physically moving up against the shore. Because December and January were bitter cold with no snow, there was absolutely no insulation.
“It’s expanding and contracting a lot, and whenever ice expands and contracts, it cracks. Assuming the temperatures are below freezing, those cracks fill instantly with water and freeze. So, the ice is never able to retreat back to its original size,” Palumbo said. “It’s always growing, inch by inch, and that’s why we call it a ratcheting effect.”
Palumbo also said the giant boulders wouldn’t even slow down the ice.
“The ice won’t think twice about moving boulders, cars, houses…it will push a house off its foundation,” he said.
Palumbo said there is a way to stave off ice damage: The shoreline must serve as a ramp rather than as a wall. The right slope, the right size of riprap stone, and a few other engineering concerns allow the ice to most often slide gently up the shoreline, rather than plow into a wall-like structure.