Buying Property along the Lake Michigan Shoreline? Let's Assess Risk vs. Reward

Michigan is home to the largest freshwater lake dune system in the world with spectacular views of Lake Michigan from atop the dunes. While beautiful, it's important to understand the risk versus reward if you are considering buying a property along the shoreline. Point Blue scientists conduct bluff and shoreline assessments to assess bluff stability and shoreline vulnerability during the due diligence period of a property purchase or anytime a landowner experiences erosion. But first, let's discuss a few key items to better understand shoreline topography.

Why do we have dunes?

During the most recent glacial retreat, sand and other materials were deposited as glacial drift. Over time and a complex sequence of advances and retreats, the drift eroded, was transported, sorted, and redeposited by wind and water, becoming sand. Continued erosion and transportation of sand builds and replenishes dunes. Fine sands are carried out into deeper waters, and larger grains and pebbles are moved inland where they dry out and are eventually deposited. As sand dries, it become less stable. Over time, sand becomes covered with grasses and other vegetation. When vegetation prevents the wind from moving the sand, the dunes are stable. The movement of sand begins again under increased winds or low groundwater tables when the sand is again exposed to the wind.

How does the water level of Lake Michigan affect our shoreline?

Lake water levels are due to changes in precipitation and evaporation. When paired with more erratic weather patterns and severe storm events, high waters can threaten infrastructure and recreation. While Lake Michigan has historically seen rising and falling water levels, weather patterns are becoming more variable. So much so that past events and conditions may not necessarily inform the lake’s future, as evidenced by the July 2019 Lake Michigan water levels, some three feet above mean summer levels, causing severe erosion for homes close to the water’s edge. We didn’t see that one coming. As we have seen, wave action on shorelines with narrow beaches can attack the bases of bluffs, eroding the toe, steepening the slope and decreasing bluff stability. This process is most active during the winter months when storm-generated waves increase in size and storms in frequency. The construction of shoreline protection, such as seawalls, revetments, and sandbags, designed to protect the toe of the bluff from erosion can be expensive and ineffective if not professionally installed, and in most cases requires a permit by the State or US Army Corps of Engineers. Point Blue can provide reputable contractor contacts and assistance with permit applications.

So, I don’t need to be concerned about rising lake levels and erosion since water levels are falling?

While wave activity, especially during periods of high water, can attack the base of the bluffs eroding the toe, steepening the slope, and decreasing bluff support, there’s more to be concerned about than high water and heavy seas. Shoreline topography, wave action, groundwater, surface water runoff, and weathering can all affect bluff stability. Swales, gullies, fissures, and rills direct surface water movement affecting the accumulation of sub-surface water and groundwater. The bluff face can concentrate and accelerate runoff, increasing surface erosion. Soils and bluff materials vary greatly. The soil characteristics and their properties can influence the extent to which a site may be prone to erosion and slope instability, aside from the effects of high lake levels and wave activity.

Planning to clear the bluff face for a better view?

Exercise caution when making bluff modifications. The removal of vegetation, especially woody vegetation, increases and channels runoff causing a greater potential to erode the bluff face. Bare surfaces allow soils to become more saturated and prone to mass soil movement, especially during heavy rains.

Anything else I should be concerned about?

Perched water tables. If the upper soil layers (sands) are coarse-textured and permeable, water may percolate down until it reaches a layer of lower permeability (denser clays). This interruption of groundwater movement is often referred to as perched water table; its subsequent lateral movement and discharge on exposed bluffs is commonly observed as a seep or spring. When the soils above the impermeable layer become saturated, they are subject to landslides in the form of slumps, earthflows, and debris avalanches.

If you are considering a property purchase along the Lake Michigan shoreline, contact Point Blue for a bluff and shoreline assessment. We’ve been assessing shoreline properties for nearly 20 years. We've probably worked on your neighbor’s property.  Connect with us to learn more about how we can help you navigate your shoreline project. Point Blue focuses on helping clients reduce their environmental risks while protecting our natural resources for a more sustainable future.