SELECTION AMONG AVAILABLE OPTIONS
SHOREFORM COMPATIBILITY
Certain approaches are better suited to particular shoreline configurations than others. It is
important to choose a method appropriate to the dominant shoreform at the site.
Bluff Shorelines
The no action alternative can be appropriate since it does not disrupt the natural shoreline
processes and requires no investment for protective structures. The property, however, may eventually
be totally destroyed by erosion. While relocation also does not disrupt shoreline processes and
permanently eliminates any threat to buildings if done properly, it also requires special equipment and
skills and can cost as much as or more than a protective structure. Bulkheads are ideally suited either
for full-height retention of low bluffs or as toe protection for high bluffs. They can be constructed of
readily available materials, are easily repaired if damaged, and are particularly useful with steep
offshore slopes. They can, however, induce toe scour and loss of remaining beach material from the
force of reflected waves. They also have high initial costs and some require special pile driving
equipment which may have difficulty reaching the work site. Revetments are sometimes effective in
bluff situations. Low bluffs that can be regraded to a stable slope may be effectively protected by
revetments. Revetments can protect the toes of high bluffs, either alone or in conjunction with another
device. Breakwaters reduce wave energy reaching the bluff but do not provide positive protection to the
toe. They may build or maintain a sand beach, which provides some protection against normal waves
but would be ineffective against storm waves. They require an adequate sand supply and gentle
offshore slopes. Groins provide only a buffer by building or holding a beach. Since they require a
natural sand supply, they would not work in a clay or silt bluff area unless sand were imported. Beach
fills only dissipate normal wave action and would not be effective during severe storms. Vegetation
provides little protection until well established and, even then, does not positively protect against large
storm waves. Drainage controls are mandatory if groundwater and infiltration adversely affect slope
stability. They provide no toe protection against wave action and can be expensive. Also, they are
difficult to properly design, and may require the efforts of a qualified professional engineer. Slope
flattening provides a permanent solution for slope stability problems but does not provide protection
against continued wave action. It also requires adequate setback room at the top of the bluff for the
slope. Perched beaches would protect the bluff from normal wave action but would not provide
positive toe protection during storms. A combination approach can be the best solution. For instance,
drainage controls should be used as needed, possibly with slope flattening as well. Toe protection
could be provided with a revetment along with a fronting sand beach for additional protection (provided
offshore slopes are mild). Vegetation planted on the regraded slope would prevent erosion from runoff
and also help to stabilize a beach fill.
Sand Beaches or Low Plains
The no action and relocation alternatives are applicable. Bulkheads are generally inappropriate unless
an elevated feature is needed, such as a promenade or parking lot. Vertical bulkheads induce toe scour
and wave reflections, and could cause a total loss of beach. Revetments are suited for protecting features
directly behind the beach since they absorb wave energy and are flexible if settlement occurs. However,
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