AVAILABLE OPTIONS
Three options are available when confronted with an erosion problem: take no action, relocate
endangered structures, or take positive action to halt the erosion. The latter includes devices that either
armor the shoreline, intercept or diminish wave energy offshore, or retain earth slopes against sliding.
Any alternative requires evaluation of the shoreform, planned uses of the land, money and time
available, and other effects of the decision.
NO ACTION
The no action alternative is used to help evaluate different options. When confronted with an
erosion problem, the first, reaction is to act immediately. What is not realized at first is the expense of
even low cost solutions. Therefore, it is advisable to estimate the losses involved in doing nothing,
particularly if only undeveloped land or relatively inexpensive structures are threatened. Also, erosion
may be caused by temporary factors (e.g., unusually high Great Lakes levels), and in such cases, it may
be advisable to wait for the erosion rate to slow before acting.
RELOCATION
No action is generally unacceptable, and in most cases, steps must be taken. Before investing in
shore protection, however, physical relocation of endangered structures should be considered. This could
involve moving them either to a different area or farther from the water on the same lot. Moving a
building involves considerable expense which could be wasted if it is not moved back far enough.
Therefore, it is necessary to evaluate the erosion rate (feet/year) and the likelihood that this rate will
continue at or below historical levels through the required life of the setback.
BULKHEADS AND SEAWALLS
"Bulkheads" and "seawalls" are terms often used interchangeably in referring to shore protection
structures. Bulkheads are retaining walls, however, whose primary purpose is to hold or prevent sliding
of the soil. While they also provide protection from wave action, large waves are usually beyond their
capacity. Seawalls, on the other hand, are massive structures used to protect backshore areas from heavy
wave action. Their size generally places them beyond the range of low cost shore protection. They are
also not generally needed in sheltered waters where large waves do not occur.
Bulkheads may be employed to protect eroding bluffs by retaining soil at the toe, thereby
increasing stability, or by protecting the toe from erosion and undercutting. Bulkheads are also used for
reclamation projects where a fill is needed at a position in advance of the existing shore. Finally,
bulkheads are used for marina and other structures, where water depth is needed directly at the shore
(Figure 7).
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