Swept Away

There’s a reason we call the Great Lakes “great.” They’re substantially bigger than other average inland lakes, and with this size comes much greater energy—these vast bodies of water possess frightening power. Mingle this with heavy winds or a mighty storm, and the Great Lakes can do some considerable damage as the waves collide and crash against the shoreline.

The constant push and pull of the Great Lakes eats away at the shorelines, moving sand and soil from one area to another. This makes it so the shorelines are constantly changing. This process where the waters wear away at the shores is referred to as shoreline erosion.

Dynamic Shores

Environmental Quality Specialist Kate Lederle from the Michigan Department of Environment, Great Lakes, and Energy is an expert when it comes to shoreline erosion in the Great Lakes area. She explained that a large portion of the Lake Michigan shoreline in particular is made up of sand, with dunes all along its eastern shoreline. When you factor in the wave energy and the distance these waves can travel across the width of the lake, the waves are able to gather enormous amounts of energy to wash away the sandy shores.

“It’s the same thing in Lake Superior and Huron,” added Lederle. “We have a lot of these sandy shorelines and because of the higher water levels right now, we are experiencing waves reaching further inland along the shore.”

With the higher water levels giving the waves more reach, the waves are able to wash away a greater amount of sand which then goes out into the lake and gets redistributed along another shoreline or beach. Lederle pointed out that this isn’t necessarily a bad thing because once the water levels go down again, you’ll find some lovely beaches on the shoreline which are perfect for boaters and beach goers on those sunny days.

Staying Back

Erosion can happen very rapidly on the shorelines depending on the strength of the storm and the wave energy. “Just think about when you splash water on a wall of sand and how it falls apart,” described Lederle. “Some places can lose up to 20 feet in just one storm event and that’s considerable.”

This makes it so if you have your home on the shoreline, there’s a real possibility it could eventually get washed away if you haven’t built it far enough back. Shoreline erosion is quite concerning for shoreline property owners and people often have to move their homes back.

Sadly, some people have lost their homes to the eroding shoreline. There are homes that have been condemned because they’re not safe to live in and a few structures have even gone over the edge.

Dredging Issues

Great Lakes boaters are loving the higher water levels right now because they can get in and out of their harbors easily, which isn’t always the case. Usually, when water levels are lower, the shoreline erosion causes dredging issues.

“What happens is the sand gets eroded into the lake and then it redistributes along the shore,” explained Lederle, “and often times it redistributes into the harbors.”

All the sand gathering at the bottom clogs up the harbors, making it necessary to dredge them—remove the sand from the bottom of the harbor so the boats won’t get stuck. However, with the higher water levels, dredging isn’t necessary right now since there’s plenty of water to get boats in and out of the harbors.

The higher water levels allow more sand to move around freely. The sand will still settle at the harbor mouths, but with the higher water levels boaters will still be able to access the harbor. When the water levels go down there will be more sand on the beaches to build and rebuild sand dunes along the shoreline.

Short-Term Solution

Shoreline property owners often ask for permits to put in-shore protection so they can attempt to slow down erosion. This protection usually comes in the form of large rocks or boulders placed along the eroding shoreline—this is something called a rock revetment.

These large boulders break the wave energy, lessening the likelihood that a house along the protected area will fall in. However, Lederle highlighted that shore protection is a short-term solution, not a long-term one.

“Eventually what happens with shore protection is the property owner ends up being on a little peninsula because the shoreline erodes when the waves and energy come around them on either side,” said Lederle. “We call it flanking. What happens then is they have to put more rocks around the side of their house.”

When this occurs, it usually evolves into a problem of space. You run out of room for your house when you live on a little peninsula surrounded by boulders. For example, if you need a new septic system, you won’t have anywhere to put it.

The Further, The Better

According to Lederle, the best thing you can do if you want to build a beachfront home on the Great Lakes is to build as far back from the shoreline as you can. In doing this, the likelihood of that house still being there 50 to 70 years from now is much greater than if you put it right up against the shoreline.

“I think a person needs to understand that the Great Lakes have a very dynamic shoreline system,” stated Lederle. “In the long-term, if you put your house farther back, you’re more likely to have a house to pass on.”

With all that being said, it’s important to remember that shoreline erosion is a natural process and is not necessarily a bad thing for Great Lakes boaters unless the redistributed sand clogs the inlets and harbors. However, with the currently high water levels, this isn’t too much of a concern, and stumbling across newly-formed sandy beaches to play on once the water level recedes is always a delight.

For More Information

Michigan Department of Environment, Great Lakes, and Energy

www.michigan.gov/egle