MPR News by Kristii Marohn and Ben Hovland
On lakes across Minnesota, it’s common to see shorelines buffered with boulders, often stretching hundreds of feet across and several feet deep.
These barricades of large rocks, known as riprap, are designed to keep soil from crumbling into the lake due to waves or high water. For many home or cabin owners, riprap also creates a neat, aesthetically pleasing shoreline, a status symbol for up-north lake life.
But armoring lakeshores comes with an environmental cost. Rocks may stop erosion, but they’re also hard and unyielding. They don’t offer habitat for fish, turtles, birds or pollinators.
And they don’t slow water running off the landscape, which can carry nutrients from lawn fertilizers that are harmful to lakes. Those nutrients, like phosphorus, pollute the water and fuel algae blooms. Read more.