Resolution 176-1979e
RESOLUTION # 176-1979
WHEREAS, the BOARD OF COUNTY COMMISSIONERS of MONROE County,
Florida, approved an application for James Hansen to construct a
boat ramp and slip and approximately 60 linear feet of seawall, and
WHEREAS, the Department of Environmental Regulation pursuant
to Section 253.124 Florida Statutes, requires that before a State
Permit can be issued that a Biological Assessment made by DER be
read into the Minutes of the County Commission.
NOW, THEREFORE BE IT RESOLVED, that the following Biological
Assessment be read into the Minutes of the County Commission and
approved by that same body.
The applicant proposes to construct 60 linear feet of vertical
concrete seawall out from MHW to regain eroded property and tie in
to an existing adjacent residential seawall. An artificially deep
peripheral channel exists just outside the location of the proposed
seawall. The seawall would be constructed with concrete sheetpile,
have a 5' wide cap on top and be tied back with concrete deadmen.
All work will be performed from the applicant's uplands but due to
the location of the proposed wall, 10-15' waterward of MHW, access
will also be through the submerged area behind the wall site. The
application states that no material is to be placed waterward of MHW
(Section 6). Depending on the depth of the fill, it is estimated
that about 100 cubic yards of fill material will be placed waterward
of MHW as fill behind the seawall.
Also proposed is the excavation of a boat basin 15' x 30' x -4.5'
average depth, and an adjoining upland boat ramp 15' x 30'. The ramp
surface would be reinforced concrete as would the sides (3' wide cap
on top) of the basin and ramp. Excavation would be performed by
backhoe and again due to the eroded shoreline, access would be through
some submerged areas.
Additionally, a week gate comprised of vinyl coated chain link and
12' tube framing and with the dimension 17' wide x 4.5' high will be
placed on hinges and mounted across the entrance of the boat basin.
The top rail will be placed at +4.0' MSL and the lower rail at
-2.5' MSL.
The project site is on the open -water shoreline of the Gulf side of
Marathon. It is located in a residential area, about 75% developed
and much of the uplands was gained by the excavation of residential
canals and peripheral channels. Across the deep peripheral channel
out from the applicant's shoreline are relatively shallow productive
flats and baybottom. Much of the local Shoreline is altered with
numerous discontinuities.
The upland portion of the site is old eroded fill and is sparsely
vegetated. Some scrub vegetation, a few transitional zone succulents
and a few Australian pines (Casuarina e uisetifolia) are present.
The shoreline is eroded rubbl-e—with little attack -vegetation in the
submerged areas. This rubble extends out about 10-15' below MHW and
then drops into a deep peripheral canal about 50-70' wide and an
estimated 10-15' deep. Similar shoreline exists for about 150' to
west of project site. West of this is a vertical concrete seawall
APPROVED ON-1 -14-)
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along the edge of the channel. Because of the NE orientation of this
shoreline and the irregular nature of the general area shoreline,
creating a cove effect, it is believed that windblown organic debris
is a problem in this area, especially in the fall and winter. During
the present site inspection, a wrack line of floating seagrass up
to 10-12' wide was present. Subsequent inspections of other nearby
shoreline where pockets, basins and coves were present, confirmed
that large amounts of seagrasses accumulate and are trapped in the
general area due to the altered shorelines. Bottom types in some
of these areas were found to be soft with settled organic debris and
silt.
As revised (6/13/79), and with the addition of the weed gate, it is
felt that the original objections to beh excavation of a boat basin
on this site have been overcome. Although the use of a mesh size
as large as standard chain link may allow the passage of some floating
grass and debris, it is believed that a gate confluent with the
seawall to be constructed will allow the free movement of most of
this material along the wall in the direction of the prevailing wind.
The functional value of a gate of this type will only be realized if
the gate is properly maintained and used as intended.
Due to the eroded nature of the shoreline and the presence of an
existing bulkhead to the east no adverse impact of the proposed
bulkhead is anticipated.
BE IT FURTHER RESOLVED, by the Board of County Commissioners
of MONROE County, Florida, that said Board hereby gives its approval
for the construction of the above mentioned work.
RESOLVED this 14th
Regularly scheduled meeting.
day of August 1979, at a
BOARD OF COUNTY COMMISSIONERS
MONROE County, Florida
ATTEST: j Cha rman
Clerk
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