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Proposed Restoration Measures:
Barrier Shoreline Restoration
Barrier Shoreline Restoration Measures
Barrier
shoreline restoration will target areas along the southern edge
of the Barataria Basin. Back-barrier marsh and wooded habitats will
be included in the restoration plans. The goal of the projects is
to increase the natural ability of the barrier shoreline system
to sustain itself while restoring, protecting and increasing the
quality and quantity of its habitat. Measures being considered include
those described in letters "A" through "L."
(A) Nourish Shoreline Shoreline nourishment will be accomplished
by introducing sand into the near-shore zone to halt or minimize
shoreline retreat in areas with some of the highest erosion rates
in the country. Introduced sand will be placed directly on the shoreline
or established in feeder berms in the nearshore area. Sand fencing
and vegetative plantings will be included where appropriate.
(B)
Build Dunes Dunes will be built through sand placement and possibly
sculpting in areas where the dunes are very small or nonexistent.
Sand fencing and vegetative plantings will be included where appropriate.
(C) Create/Nourish Marsh Marsh will be created through traditional
dredge and fill methods or nourished with a diluted slurry or spray
dredge, and will include vegetative plantings of multiple native
species where required. Marsh nourishment will be used in areas
of broken marsh to avoid covering existing vegetation, whereas traditional
fill methods will be used in areas of open water. In open areas,
dredge and fill without containment could nourish adjacent marsh.
Aquatic organism access and interspersion of tidal creeks and ponds
would be maintained.
(D) Fill Pipeline Canals Numerous canals cutting through the islands
or shoreline create weak points that are likely to increase erosion
and breaching. Loss of sediment occurs when storms cause the washover
of shoreline material into shore-parallel canals that are close
to the gulf shoreline. Selected canals will be filled and planted
to create marsh or filled to higher elevations (ridges) and planted
with woody vegetation. On the headland, the LOOP and BP pipeline
canals are conduits that have altered the hydrology and salinity
of the back marshes in their vicinity. These will be filled or plugged
at strategic locations.
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(E) Remove Existing
Breakwaters A series of breakwaters constructed of sunken barges
are located near the western portion of the headland and will be
removed if they prove to be an impediment to a beach nourishment
project.
(F) Restore Maritime Forest The relic beach ridges that supported
the maritime forest on Cheniere Ronquille have almost eroded away.
The remaining fragment will be expanded either through back-dune
construction, to mimic relic beach ridges and provide the elevation
needed for maritime forest species, or by planting other woody species.
(G)
Construct Terminal Structure at Barataria Pass West Grand Terre
Island is on the downdrift end of a littoral cell and sediment is
currently being lost into the channel or to the Barataria ebb tidal
shoal. This measure proposes that a terminal structure (armoring,
t-groin, etc.) be used both to prevent the loss of material from
the western end of West Grand Terre Island and to protect Fort Livingston,
a historical resource.
(H) Protect Bay-side Shoreline This measure will provide shoreline
protection (segmented breakwaters, artificial reefs/islands, armoring)
on the bay side of the Grand Terre islands to decrease bayside marsh
erosion, with the added benefit of protecting cultural resources
on West Grand Terre Island.
(I)
Restore Shell Island This measure will rebuild the island with dredged
material to restore shoreline integrity and provide protection to
backbarrier areas, and includes construction of beach, dune and
back-marsh habitats.
(J) Modify the Empire Jetties Modifications will be made to the
Empire Jetties to improve longshore sediment transport.
(K) Restore/Reconnect Sandy Point The island will be enlarged using
dredged sediments to reconnect to the nearby western shoreline and
increase shoreline integrity.
(L) Create Artificial Ridges/ Reefs Instead of, or in addition to,
Shell Island reconstruction, recycled oyster shells or other hard
material will be used to create storm ridges and reefs. These ridges
and reefs will provide additional habitat types and reduce the impact
of waves along the back-barrier areas.
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