Four Mile Canal Terracing and Sediment Trapping (TV-18)

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The main cause of current marsh loss is a shoreline erosion
rate of approximately 8 feet/year. A combination of wind
and wake energy prevents sediments introduced by the Gulf
Intracoastal Waterway (GIWW) via the Vermilion River and
Four Mile Canal from allowing subaerial marsh development
in the area.

Reduction of shoreline erosion will be achieved by the
buffering capacity of the constructed terraces. The proposed
terrace layout is very different for each area of the project.
The “fish net” design for Little Vermilion Bay is designed to
allow sediment deposition and the terraces in Little White
Lake are aligned to reduce the wind generated waves, thus
reducing shoreline erosion. Thus, marsh habitat will be
created in two ways within the Four Mile Canal Terracing
Project area. First, marsh will immediately be built by
creating approximately 90 terraces from dredged material
and planting them with smooth cordgrass. This action alone
will create 70 acres of subaerial land. Second, by reducing
fetch and wave energy, terraces will promote the deposition
of suspended sediments in the shallow water adjacent to
the terrace edges in Little Vermilion Bay and Little White
Lake. This will slowly build marsh over the life of the
project as subaerial land is built and plants naturally become
established.

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The project is located approximately 4 miles south of
intracoastal City in Vermilion Parish, Louisiana. The
project area includes all of Little White Lake and part of the
northeastern embayment of Little Vermilion Bay.

Project construction was completed in May 2004. No
maintenance activities have been undertaken as of 2017
and none are planned prior to project closeout. While some
terraces have eroded since construction, in general the
project is in good condition and functioning as intended.
Shoreline erosion has decreased and wetland acreage has
increased since construction.

This project is on Priority Project List 9

The Federal Sponsor is NOAA NMFS

The Local Sponsor is CPRA

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Pecan Island Terracing (ME-14)

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In the mid-1950s continuous dikes were constructed and water was pumped off the marsh, transforming it into dry pastureland. As a result of oxidation, the soil elevation has subsided 1 to 2 feet. Deterioration and loss of the perimeter levees in recent years has converted the entire area into a shallow, open water lake with a few small marsh islands resulting in a net loss of fisheries habitat.

The restoration project will reduce marsh erosion by creating emergent terraces designed to minimize wave fetch across open water and, at the same time, creating linear marsh features. Future marsh loss will be prevented and brackish marsh will be restored. Construction of the earthen terraces in shallow water areas will also convert areas of open water back to vegetated marsh creating more habitat for fish and shellfish. The project calls for constructing adjacent terrace cells in a staggered gap formation, each bordered by terraces made from dredged material. Terraces will be built and planted with smooth cordgrass (Spartina alterniflora), and California bulrush (Scirpus californicus). Plantings may also occur on the north side of the terracing area.map.jpg

 

This project is located in southeastern Vermilion Parish, Louisiana, approximately 5 miles north of the Gulf of Mexico just south of Pecan Island and Louisiana Highway 82.

The project construction was completed in August 2003, initially creating over 122 acres of emergent marsh. The monitoring plan was finalized in November 2001 and data collection has been ongoing since that time.

This project is on Priority Project List 7.

The Federal Sponsor is NOAA

The Local Sponsor is CPRA

Little Vermilion Bay Sediment Trapping (TV-12)

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High winds and waves prevent GIWW sediments transported down the Freshwater and Schooner bayous from settling and forming the basis of vegetated marsh. This same wind and wave energy also increases shoreline erosion rates.

This project involved the construction of a series of vegetated terraces to diminish waves in Little Vermilion Bay, helping to increase sediment deposition and reduce the rate of shoreline erosion. A pattern of channels was dredged 100-feet wide and 6-feet deep to beneficially distribute sediment from the GIWW through the Freshwater and Schooner bayous. Dredged sediments were used to construct 23 earthen terraces with a combined length of 23,300 feet. After settling, the average height of the terraces was 3.5 feet above mean sea level.

The bases of the terraces were planted with 20,450 containers of smooth cordgrass (Spartina alterniflora).

The design allows commercial and recreational fisherman to access the project area, and it stimulates fishery production by creating new habitat and increasing shoreline length.

In 1998 alone (prior to the project’s completion) 40 acres of wetland habitat were created.

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This project is located in the northwestern corner of Little Vermilion Bay at its intersection with the Gulf Intracoastal Waterway (GIWW) in Vermilion Parish, Louisiana. The project area encompasses 964 acres.

Monitoring is underway and preliminary observations show that the terraces are growing in width, and bay depth between terraces is decreasing indicating marsh expansion in the project area.

This project is on Priority Project List 5.

The Federal Sponsor is NOAA NMFS

The Local Sponsor is CPRA

Vermilion Parish Coastal Day

On Friday, June 10th, the Vermilion Parish Coastal Protection and Restoration Committee hosted the first Vermilion Parish Coastal Day in Intracoastal City, Louisiana. Joining the Vermilion Parish Coastal Committee was the Vermilion Parish Police Jury and leaders of Louisiana Coastal Protection and Restoration Authority (CPRA). The one-day event was dedicated to educating local landowners, government officials, and the general public on the success of previous coastal restoration projects as well as current coastal issues in hopes of uniting the community to support the progression of coastal efforts within Vermilion Parish.

Ronald Darby, President of Vermilion Parish Policy Jury, and Kevin Sagrera, Chairman of johnny bradberryVermilion Parish Coastal Committee, welcomed Johnny Bradberry, Executive Assistant to the Governor for Coastal Affairs and CPRA Chairman. Bradberry gave brief updates on current bills and legislation pertaining to coastal projects. Michael Ellis, Executive Director of CPRA, discussed the valuable natural resources available in Vermilion Parish. Ralph Libersat of the Vermilion Parish Coastal Committee presented an overview of Vermilion Parish coastal projects, explaining the critical need to protect what is there now, as presentationopposed to having to recreate land years into the future. Libersat discussed the $92 million of coastal project expenditures in Vermilion Parish to date:$70 million from CWPPRA, $18 million from Vermilion Parish, and $3.4 million from surplus funding, giving a conservative total net benefit of 5180 acres. Libersat highlighted a few CWPPRA projects such as ME-31, TV-12, TV-18, TV-63, and TV-03; Libersat continued by expressing that Vermilion Bay is losing wetlands at a rate of 8-10 feet per day.

Following lunch was a site visit to two restoration project areas along Freshwater Bayou and Vermilion Bay. The first project site was Freshwater Bayou Marsh Creation (ME-31), located west of Freshwater Bayou and north of the Freshwater Bayou Locks; this project is in the Engineering and Design phase to create and/or nourish approximately 401 acres of marsh using dredged material. The second project site was Little Vermilion Bay Sediment Trapping (TV-12), located in the northwestern corner of Little Vermilion Bay at its intersection with the Gulf Intracoastal Waterway (GIWW); this project has been completed and was successful in shoreline protection and sediment trapping with terraces.