Resolution 002-1980
RESOLUTION iF
2-1980
vJHEREAS, the BOARD OF COUNTY COr1MISSIONERS of MONROE County,
FLORIDA, has received an appl ication from Richard Y. Rowe, to
construct:
1,095 linear feet of concrete slab bulkhead below mean high
water on a natural waterbody. This bulkhead will connect to existing
bulkheads on each end. Backfill will be placed landward of the
seawall and riprap will be placed at the toe of the seawall. About
300+ cubic yards of backfill and riprap are estimated to be necessary
bel~J mean high water and 80t cubic yards above mean high water.
All work will be done from, and all materials and equipment will be
transported to the site over existing uplands, Turbidity screens
are proposed to be used where necessary.
The project site is located on old filled uplands on a corner formed
by the junction of Sister's Creek and Boot Key Harbor. Sister's
Creek handles considerable tidal flow to the Florida Straits to the
south and Boot Key Harbor flushes to the west into Moser Channel.
The western shoreline of Sister's Creek is formed by extensive red
mangrove fringes of Boot Key. Residential shorelines with some
alterations comnrise the eastern shoreline of Sister's Creek and the
north side of Boot Key Harbor is altered by residential finger canals
and extensive residential development.
Passing vessel traffic during the site inspection produced considerable
turbidity in adjacent waters as the wave-wash impacted the exposed
marl embankments on the point of the project site. This resulted in
a layer of marl sediments on the grassed bottom on the west shoreline.
This constant erosion is believed to be a limiting factor in the
develop~ent of benthic communities in the immediate area. The marl
embankments of this point are about 3-4.5 feet high and exist for
about lOa feet of the shoreline. Subtidal areas in front of this
embankment are much less vegetated but do contain several species of
benthic algae and out about 15-30 feet begin turtle grass and shoalgrass,
On ebb tides, the Sisters Creek subtidal zones receive much of the
eroded marl from wave wash resulting in softer sediments but seagrasses
are present a short distance below mean low water at about -1.5 to
-4 feet mean low water. Mangroves along the west side are more
developed than on the north shoreline but due to severe wave-wash are
not effective in stabilizing the marl embankment. Red and black
mangroves are present along this bank but provide little habitat
or protective cover to fishes and invertebrates for the same reason.
Net samples in turtle grass at about -2.5 feet mean high water on
the harbor side produced numerous Caridean crustaceans of several
species? tubiculous polychaetes, gastropod molluscs (2 species),
hermit crabs, a nudibranch and a pipefish. Sampling in shoalgrass
on the same shoreline also at about -2.5 feet mean high water
produced numerous shrimp as well as an abundance of gastropods,
amphipod and tanaid crustaceans and hermit crabs. Samples in an area
of mixed seagrasses at about -3 feet mean high water on the west side
of the site also produced shrimp, amphipods, tanaids and gastropods.
These organisms indicate a productive, detrital based, benthic
community which forms an integral part of the marine food webs of the
local area.
The construction of this seawall with riprap placed at the toe along
the entire length will provide a benefit to local biological
communities by eliminating the erosion of the marl embankments. This
will allow a stabilization of subtidal benthic communities especially
along the point and west side of the property. Intertidal zones are
presently essentially unvegetated (except for scattered mangroves)
and provide only a sloped shoreline for energy release of wave-wash.
BOOK
D
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PAGE_ OOy.
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APPROVED ON
2- 2-'
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A bulkhead with adequate riprap along the toe will provide a similar
mechanism.
The singular cross-section drawing included in the application shows
the placement of the seawall several feet waten~ard of mean low
water and the riprap only about 1-2 feet high in front of the wall.
Placement of these materials below mean low water has the potential
to adversely impact the existing productive seagrass and algae
communities present below mean low ~Jater. The effects of scouring
by severe wave wash that if reflected by the seawall and riprap at
this location could have a negative long-term impace on adjacent
benthic habitats, especially at lower tide levels. The slope of the
intertidal and subtidal bottom at the site is much more gentle than
is diagrammed in the application.
BE IT FURTHER RESOLVED, by the BOARD OF COUNTY COMMISSIONERS
of MONROE County, FLORIDA, that said BOARD hereby given its approval
for the construction of the above mentioned project.
RESOLVED THIS
3,,<:\
day of January, 1980, at a Regularly
scheduled Meeting.
BOARD OF COUNTY COMMISSIONERS
MONROE COUNTYl. FLORIDA
/ 1
BY
M
ATTEST:
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