EM 1110-2-1100 (Part V)
31 Jul 2003
Many other benefits exist. As seen in Figure V-3-3, since the 1960s, beach nourishment has been
the selected alternative for shore protection. Substantial recreation and tourism benefits have resulted
for local, state, and Federal governments. Waterfront property is generally of greater value and
generates higher property taxes. Innumerable secondary (ripple effect) benefits result from the
coastal, beach-related travel and tourism industry. The economic value of beaches has been well
documented (Houston 1995a; 1995b).
A good example is Miami Beach, Florida, which was renourished in 1979 by a joint Corps of
Engineers - City/County government project costing million. The capitalized annual cost is
about million and the project has lasted more than 20 years without the need to renourish the
beach. Attendance at the beach increased from 8 million in 1978 to 21 million in 1983 (Houston
1995a). More than 2 million foreign visitors spend over billion annually at Miami Beach (Cobb
1992). The Miami Beach experience is roughly 0 return in foreign exchange for every
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invested in beach nourishment (Houston 1995a; 1995b; 1996).
Beach nourishment can also enhance the natural environment. Widened beaches reduce the potential
for new, tidal inlet formation during storms at narrow reaches of barrier islands. The economic losses
to the protected bay environment (property, recreation, farming, fishing, infrastructure, etc.) can be
estimated and added to the storm damage and other benefits for the impacted barrier island. In
general, however, environmental benefits of the enhanced, flora and fauna habitat are difficult to
quantify monetarily.
All benefits are site specific. Here, we briefly outline the methodology commonly employed to
determine storm damage reduction benefits. A key factor, as illustrated in Figure V-3-2 is distance
between the reference baseline and the sea. Steps in the methodology are:
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Make a structure inventory (residential, commercial, public). Employ aerial, orthodigital
mapping and Geographic Information System (GIS) technology where possible and adapt new
technologies.
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Obtain software to calculate the depreciated replacement cost of the structures and content value.
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Obtain the water level, storm frequency-of-occurrence data for the site, and accompanying wave
and shoreline erosion data. The EST methodology previously discussed should be employed,
whenever possible.
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Obtain and run storm damage calculation models. Long-term erosion is included to estimated
damages under changing future conditions. The key variables are water level and position of
each structure in relation to the shoreline. Some models only treat property structure damage and
others land and infrastructure (roads, etc.) damage.
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Apply the models for both the without project conditions and for the alternatives and
subalternatives design considered for shore protection.
The result is the average, annual damages prevented (benefits) of each alternative. Differences for
each alternative to prevent or reduce storm damage are quantified by this approach. Complete details
can be found in Part V-8 where names and references for some of the software and models presently
employed by the Corps are presented. In general, the state of art for these damage calculation models
is less well advanced than for other areas of coastal engineering design.
Shore Protection Projects
V-3-11
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