Alcona County, MI
Lake Huron Shoreline Erosion: Alcona County's 1982 High Risk Erosion Area
This isn't a generic Great Lakes erosion risk. Michigan specifically designated shoreline parcels in Alcona Township, Greenbush Township, and the City of Harrisville as a High Risk Erosion Area back in 1982, with a Lake Huron setback line calculated to hold for at least 30 years. That window has since passed, which is exactly why a current parcel-specific check matters more here than a general awareness of coastal erosion.
This page covers what's specific to Alcona County. For the general explanation, see the national guide.
The 1982 designation: specific townships, specific parcels
In April 1982, the Michigan Department of Natural Resources formally designated shoreline parcels in Alcona Township, Greenbush Township, and the City of Harrisville as a High Risk Erosion Area under the state's then-governing Shorelands Protection and Management Act (the predecessor to today's NREPA Part 323). The designation set a required construction setback measured from the Lake Huron bluffline, calculated at the time to prevent erosion-related damage to a new structure for a period of at least 30 years. Local townships supplied the specific property tax identification numbers included in the original designation -- meaning this wasn't a broad-brush coastal label, but a parcel-by-parcel mapping exercise for this particular stretch of shoreline.
That 30-year design horizon means the original 1982 setback calculation was built to hold roughly through the early 2010s -- it has since passed. That doesn't mean the setback line is wrong today, but it does mean a buyer shouldn't assume a decades-old figure still reflects current lakebed and bluff conditions without checking EGLE's current mapping for the parcel specifically.
How Michigan's High Risk Erosion Area program works today
Today, EGLE administers High Risk Erosion Area regulation under NREPA Part 323, covering roughly 250 miles of Great Lakes shoreline statewide across Lakes Michigan, Huron, and Superior where the land is receding at a documented rate. Inside a mapped HREA, a permit is required for a "regulated use" -- in practice, most new construction -- and that permit application requires meeting the erosion-based setback distance from the shoreline rather than a standard zoning setback. This is a state permitting requirement layered on top of whatever local zoning otherwise applies (or doesn't -- see this site's separate page on Alcona County zoning, since several of the county's townships have no zoning ordinance at all).
EGLE maintains current High Risk Erosion Zone mapping through its GIS data platform, including an interactive "High Risk Erosion Zones" layer that can be queried for a specific parcel or address rather than relying on the general 1982 township-level designation described above. Checking that current map -- not just knowing that Alcona, Greenbush, and Harrisville carry a historical HREA designation -- is the actual due-diligence step for a specific shoreline parcel today.
What this means if you're buying Lake Huron shoreline land here
If you're evaluating a parcel in Alcona Township, Greenbush Township, or within Harrisville itself, start from the assumption that HREA regulation may apply -- this is documented, historical fact for this specific stretch of coast, not a general Great Lakes caution. Pull the parcel against EGLE's current High Risk Erosion Zones GIS layer or maps page to confirm current status and setback distance before assuming a building site, septic location, or addition is viable as planned.
If a structure already exists on a shoreline parcel here, ask when it was built relative to the 1982 designation and whether it was permitted under HREA rules at the time -- an older structure that predates or was grandfathered under the original designation may face different rules on a future rebuild or major addition than a new structure would today. EGLE's Water Resources Division shoreland management staff can confirm a specific parcel's current status and what a rebuild or addition would require.
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Connect with a local land specialistSources
- Alcona County Great Lakes sports fishing facilities study, land development plan and tourism promotional strategy (1982, documenting the HREA designation) — U.S. Government Publishing Office (govinfo.gov), Coastal Zone Information Center archive (accessed 2026-09)
- High Risk Erosion Areas: Program and Maps — Michigan EGLE (accessed 2026-09)
- Maps of High Risk Erosion Areas — Michigan EGLE (accessed 2026-09)
- High Risk Erosion Zones (GIS layer) — Michigan EGLE Maps & Data (accessed 2026-09)
- Harrisville State Park — Wikipedia (accessed 2026-09)
Last reviewed 2026-09