Proposed Restoration Measures: Barrier Shoreline Restoration
USGS-National Wetlands Research Center
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."
1 Headland Reach
USGS-National Wetlands Research Center
(B) Build Dunes
(C) Create/Nourish Marsh
(D) Fill Pipeline Canals
(E) Remove Existing Breakwaters
2 Grand Terre Reach
USGS-National Wetlands Research Center
(B) Build Dunes
(C) Create/Nourish Marsh
(E) Fill Pipeline Canals
(G) Construct Terminal Structure at Barataria Pass
(H) Protect Bayside Shoreline
3 Cheniere Ronquille Reach
USGS-National Wetlands Research Center
(B) Build Dunes
(C) Create/Nourish Marsh
(D) Fill Pipeline Canals
(F) Restore Maritime Forest
4 Shell Island Reach
USGS-National Wetlands Research Center
(J) Modify the Empire Jetties
(L) Create Artificial Ridges/Reefs
5 Scofield Reach
USGS-National Wetlands Research Center
(B) Build Dunes
(C) Create/Nourish Marsh
(D) Fill Pipeline Canals
(K) Restore/Reconnect Sandy Point
(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.
(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.