Homeowners increasingly use riprap—layers of rocks—to stabilize eroding shorelines. Experts warn this hard armoring raises water temperatures, accelerates pollutant runoff, and fails to support critical habitat for wildlife like fish, turtles, and pollinators. Rather than solving erosion, riprap often exacerbates ecological damage and is viewed as a short-term fix compared to more sustainable methods.
Minnesota Public Radio highlights this growing challenge in the article, "Minnesota is armoring it's shorelines with rocks, but lakes are paying a price."
Although the article focuses on Minnesota, the underlying dynamics mirror challenges faced by many freshwater shorelines - including Portage Lake in Onekama, MI:
1. Similar Shoreline Management Pressures
Homeowners near Portage Lake face erosion concerns and may consider installing riprap. However, as in Minnesota, this option can warm nearshore water, channel pollutants, and eliminate habitat at the water’s edge.
2. Ecological Tradeoffs at Play
Portage Lake, like Minnesota lakes, supports fish, bird, and amphibian species relying on vegetated, natural shorelines for nesting, feeding, and thermal regulation. Replacing these buffers with rocks could undermine those ecological benefits.
3. Riprap as a BandAid
Rather than addressing watershed root causes like runoff or vegetation removal, riprap often serves as a “BandAid”—masking symptoms rather than restoring natural function. Michigan stakeholders may benefit from considering soft-armoring alternatives (e.g., vegetated buffers, native plantings, bioengineering) that protect property while enhancing water and habitat quality.
Considering installing riprap? Explore these alternatives instead:
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Use Living Shorelines or Bioengineering: These natural approaches stabilize banks using native deep-rooted plants, logs, and coir, buffering erosion and providing habitat.
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Maintain or Restore Buffer Zones: Leaving or planting native vegetation along the shore prevents runoff, filters pollutants, and supports wildlife.