Explanation of Indicator
Armoring refers to coastal protection measures such as seawalls,
bulkheads, and other similar structures designed to prevent the
erosion of property immediately behind the structure. Armoring
of the coastline with various types of hard substances has provided
an effective means to protect development from the destructive
effects of waves and tides caused by storm events.
Armoring has a number of effects upon the immediate surroundings. Even though it is effective in protecting structures, it can have an adverse effect on property to either side or directly in front of it. Seawalls and other armoring structures are not able to absorb the energy of waves and currents as well as unaltered coastline. Therefore this energy may be deflected to either side of the structure or to the shoreline in front of the structure, leading to accelerated erosion in these areas. This increased erosion can decrease the amount of shoreline available for public use. If the threat (or perceived threat) of erosion is severe, there may be an increase in the miles of coast altered by armoring.
Miles of coastal armoring is an important indicator of the loss of natural coastline, which indirectly indicates loss of natural habitat and loss of land for public use. Monitoring the amount and effects of coastal armoring can provide valuable information regarding the present and future uses of the state’s coastal areas.
Data Characteristics
SOURCE
Baseline data, including structures erected in 1990, is
available in Coastal Armoring in Florida, Final Status
Report, December 1990, published by the Florida Department
of Environmental Protection (DEP), Bureau of Beaches and
Coastal Systems, 3900 Commonwealth Blvd., Tallahassee,
Florida 32399-3000, or at (904) 488-3181. These data
provide an inventory of the existing armoring structures.
More recent permit data is available through each of the 35
coastal county governments.
ACQUISITION
The information is available in hard copy format at no cost.
COLLECTION
The information was gathered from a comprehensive summary report
with data up to and including 1990.
Data Limitations
The data are difficult to obtain because information is
collected at the county level. There needs to be a central
reporting location where the data are compiled and analyzed.
Data Analysis
The 1990 baseline analysis for Florida's coast was conducted
on a county-by-county basis. Each county was analyzed in terms
of total shoreline length regulated by the coastal construction
control line, length of existing armoring, length of potential
armoring, and number of threatened structures. Potential armoring
was based on assessment of areas in which upland structures were
threatened by storm induced erosion; these structures included only
habitable structures and public infrastructure such as roads, water
treatment facilities, etc.
The data indicate that in 1990 about 147 miles of the 710 miles of Florida coastline regulated by the coastal construction control line, or about 21%, were armored in such a way as to protect the existing structure from a 25 year storm event. Another 51.1 miles consisted of potentially armored coastline. This is the amount of armoring which, with minor additions to the already existing armoring structures, would provide adequate protection for a 25 year storm event.
Recommendations
It is recommended that DEP’s Bureau of Beaches and Coastal Systems
collect and aggregate the armoring permit data from the local agencies
on an annual basis and develop a central database rather than leaving
this information solely with local agencies To be most meaningful
and to better illustrate the complex processes involved in coastal
erosion, this indicator should be used in conjunction with the indicator
identifying miles of eroding coastline. An analysis of the two
indicators could show a direct relationship between location of armoring
and sites of erosion.