R 281.21
R 281.21 Definitions.
Cite as Mich. Admin. Code R 281.21
Rule 1. (1) As used in these rules:
(a) "Act" means Part 323 oF Act No. 451 of the Public Acts of 1994, as amended, being
Section 324.32301 et seq. of the Michigan Compiled Laws, and known as shorelands
protection and management.
(b) "Alteration of vegetation" means to change the natural density and composition of
plants by human activity such as mowing, cutting, clearing, spraying, burning, trimming,
thinning, and other means.
(c) "Erosion hazard line" means the line along the shoreland that is the landward edge of
the zone of active erosion or the line where the 583.0 feet international Great Lakes datum
contour on Lake Michigan, the 582.2 feet international Great Lakes datum contour on Lake
Huron, or the 603.3 feet international Great Lakes datum contour on Lake Superior meets
the shoreland, whichever is furthest landward.
(d) "High bluff" means a bluff or dune that is more than 25 feet in height measured from
the appropriate elevation contour set forth in the definition of erosion hazard line.
(e) "Low bluff" means a bluff or dune that is 25 feet or less in height measured from the
appropriate elevation contour set forth in the definition of erosion hazard line.
(f) "Nonconforming structure" means a permanent structure which does not conform to
the required setback distance at the time of designation or which became nonconforming
due to erosion or became nonconforming due to a change in the required setback distance.
Permanent structures that are constructed in violation of these rules shall not be considered
to be nonconforming structures.
(g) "One hundred-year flood" means a flood that has a l% chance of being equaled or
exceeded in any given year.
(h) "Parcel" means a continuous area or acreage of land that is under the same ownership
at the time of designation.
(i) "Permanent structure" means any 1 of the following structures that is erected, installed,
or moved on a parcel of property:
(i) A residential building.
(ii) A commercial building.
(iii) An industrial building.
(iv) An institutional building.
(v) A mobile home.
(vi) Accessory and related buildings.
(vii) A swimming pool or deck that has a roof or walls.
(viii) Septic systems.
(ix) Tile fields.
(x) Other waste-handling facilities.A permanent structure shall be considered small if it
has a foundation size of 3,500 square feet or less and less than 5 individual living units. All
other permanent structures shall be considered large. "Permanent structure" does not
include recreational vehicles, travel trailers, swimming pools, or decks constructed on
pilings if the pool or deck does not have a roof or walls. A "Permanent Structure" also does
not include separate appurtenant structures which have less than 225 square feet, which are
used for picnicking or storing of recreational or lawn equipment, and which are constructed
in a manner that facilitates easy removal. The appurtenant structure shall not have a
permanent foundation and shall not be used as a residential facility.
(j) "Projected recession distance" means the distance, in feet, determined by the
department under R 281.22.
(k) "Readily moveable structure" means a small permanent structure which is designed,
sited, and constructed to accomplish relocation at a reasonable cost relative to other
structures of the same size and construction. Access to and from the site shall be of
sufficient width and acceptable grade to permit the structure to be relocated. New
construction and installations shall meet the following criteria to be considered readily
moveable structures:
(i) The buildings shall be on pilings, a basement, or crawl space. Except as noted in
paragraph (ii) of this subdivision, a slab-on-grade foundation does not meet this criterion.
(ii) Above-grade walls shall be stud wall or whole log construction. Above- grade walls
that are constructed of masonry, including stone walls, concrete poured, or concrete block
walls do not meet this criterion. Existing permanent structures shall be considered readily
moveable structures if the cost of relocation landward of the required setback distance is
not more than 25% of the replacement cost of the structure or if the existing structure meets
the criteria for new construction in this subdivision. A 1- or 2-car garage which is bolted
to a slab foundation and which does not have plumbing or interior walls is a readily
moveable structure if it meets the remainder of the requirements specified in this
subdivision. Septic systems, tile fields, or other waste-handling facilities are not readily
moveable structures.
(l) "Required setback distance" means the least distance a permanent structure can be
constructed from the erosion hazard line without a special exception. The required setback
distance is calculated using the following criteria:
(i) For low bluffs, the required setback distance shall be at the projected recession distance
from the erosion hazard line.
(ii) For high bluffs, the required setback distance is calculated by adding 1.0 to the product
of the percentage points of slope over 25% and 0.05 to a maximum of 2.O. The answer is
multiplied by the projected recession distance in feet. The following table shows sample
calculations using this formula:
Required Setback
Percent Slope 1.0 (Percent Slope over 25% x 0.05) Multiplier 25 1.0+ (0 x 0.05) = 1 30
1.0+ (5 x 0.05) = 1.25 35 1.0+ (10 x 0.05) = 1.5 40 1.0+ (15 x 0.05) = 1.75 45 1.0+ (20
x 0.05) = 2.0
The slope of the bluff or dune is measured over a 50-foot distance on the lower portion of
the lakeward facing slope of the dune or bluff.
(iii) The required setback distance shall not be greater than the projected recession
distance from the top of the lakeward facing slope of a dune or bluff.
(iv) For bluffs and dunes which have slopes of more than 60% and which are more than
100 feet in elevation above the appropriate lake elevation set forth in the definition of
erosion hazard line, the required setback distance shall be established not less than 30 feet
landward of the lakeward facing slope of the dune or bluff.
(m) "Structure zone" means an area within an environmental area where a permit under
this part is not required to engage in the activities specified in R 281.23(6).
(n) "Setback line" means the line which is the required setback distance landward of the
erosion hazard line and which is the lakeward limit for the construction of permanent
structures without a special exception.
(o) "Substandard parcel" means a lot or parcel of record or a lot or parcel which is
described in a land contract or deed that is executed and delivered before the designation
of a high-risk erosion area and which does not have adequate depth to provide the required
setback distance from the erosion hazard line for a permanent structure. “Substandard
Parcel” also means those lots which are legally created after the designation of a high-risk
erosion area and which have sufficient depth to meet setback requirements for permanent
structures, but which subsequently become substandard due to erosion processes or become
substandard due to a change in the required setback distance.
(p) "Wetland-oriented birds" means any of the following:
(i) Waterfowl.
(ii) Shorebirds.
(iii) Gulls.
(iv) Terns.
(v) Herons.
(vi) Rails.
(vii) Bitterns.
(viii) Other birds associated with coastal or wetland areas.
(q) "Wetland-oriented mammals" means any of the following:
(i) Muskrats.
(ii) Mink.
(iii) Beavers.
(iv) Otter.
(v) Other mammals associated with coastal or wetland habitats.
(r) "Zone of active erosion" means the area of the shoreland where the disturbance or loss
of soil and substrate has occurred with sufficient frequency to cause unstable slopes or
prevent vegetation of the area.
(2) The terms defined in the act have the same meanings when used in these rules.