By Andi Anderson
A new Michigan State University study has documented a dramatic rise in synthetic structures built to protect property along Lake Michigan, revealing a fivefold increase in shoreline armoring from 2014 to 2021.
The research highlights the growing tension between protecting coastal property and preserving fragile ecosystems.
Beginning in 2014, Lake Michigan experienced a surge in water levels, peaking in 2020 and triggering significant erosion of beaches, dunes, and bluffs. In response, many homeowners and communities installed hard structures such as seawalls, revetments, and groins to slow or stop wave damage.
These barriers are designed to prevent water from undermining shorelines—seawalls act as vertical barriers, while revetments use a sloped design to disperse wave energy, and groins extend into the lake to trap sand and slow beach erosion.
Assistant Professor Ethan Theuerkauf, a coastal geomorphologist in MSU’s Department of Geography, Environment and Spatial Sciences, analyzed NOAA coastal datasets and 2014 imagery against new 2021 maps he created using Google Earth Pro.
He found armored shoreline jumped from about 15 miles (4% of the coast) in 2014 to nearly 69 miles (19% of the coast) in 2021. The southern section of Michigan’s Lake Michigan coast saw the largest increase—up 351%—while central and northern stretches also recorded sharp growth.
“Despite the protective intent, this widespread armoring raises concerns about its long-term effects on coastal ecosystems and geomorphology,” Theuerkauf said. “We need further research and informed policy decisions to balance protection needs with ecosystem function and integrity.”
While shoreline armoring can successfully limit erosion and property loss, it can disrupt natural sediment transport, alter coastal habitats, and intensify erosion in adjacent areas.
Theuerkauf’s findings underscore the importance of understanding how rising lake levels and human interventions interact, offering valuable guidance for future coastal management policies in the Great Lakes region.
Photo Credit: michigan-state-university-msu
Categories: Michigan, Education