East Leeville Marsh Creation and Nourishment

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There is widespread historic and continued rapid land loss
within the project site and surrounding areas resulting from
subsidence, wind erosion, storms, and altered hydrology.
The wetland loss rate for is -1.53%/year based on USGS data
from 1984 to 2015. Furthermore, the limits of Southwestern
Louisiana Canal are difficult to determine in some areas
because land loss is causing the coalescence of the canal
with adjacent water bodies. Natural tidal flow and drainage
patterns which once existed are currently circumvented by
the increasing area of open water. Data suggests that from
1932 to 1990, the basin lost over 245,000 acres of marsh, and
from 1978 to 1990, Barataria Basin experienced the highest
rate of wetland loss along the entire coast.

The project goal is to create approximately 358 acres and
nourish 124 acres of saline marsh east of Leeville.
After consideration of three potential alternatives, features
and an alignment were selected to establish an arc of
wetlands along the north side of Southwestern Canal,
Lake Jesse, and the west side of South Lake. This is to
begin rebuilding the structural framework of wetlands
east of Leeville and provide protection for Leeville from
southeasterly winds and tides. A robust engineering and
design cost was included for full flexibility during Phase 1
to expand the project if cost allows or to assess alternative
configurations, if necessary. The proposed features consist of
hydraulically mining sediment from a borrow source in Little
Lake west of Leeville and pumping dredged material to
create and nourish marsh east of Leeville. The disposal areas
would be fully contained during construction and gapped
no later than three years post construction to facilitate
establishment of tidal connection and function. Additionally,
a portion of the created marsh acres would be planted with
smooth cordgrass following construction to help stabilize the
created platform by increasing the rate of colonization.

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This project is located in Region 2, Barataria Basin, Lafourche Parish (primary)
Region 3, Terrebonne Basin, Lafourche Parish.

This project was approved for Phase I Engineering and
Design in January 2016.

This project is on Priority Project List (PPL) 25.

The East Leeville Marsh Creation and Nourishment’s sponsors include:

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Sabine Refuge Marsh Creation Cycle III

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The project area is experiencing marsh degradation due to
saltwater intrusion and freshwater loss. This has resulted
in the conversion of vegetated intermediate marsh to
large shallow open water areas. Salinity migrates into the
region from the Calcasieu River. Southerly winds push
saline waters into the project area through existing canals
and bayous. Wind driven waves cause further loss of the
remaining marsh fringe.

Cycle III consists of the creation of 232 acres of marsh
platform using material dredged from the Calcasieu River
Ship Channel. Between February 12 and March 31, 2007,
828,767 cubic yards of dredged sediment material was
placed into the Sabine Refuge Cycle III marsh creation area.
The dredged material is contained by earthen dikes. Lower
level earthen overflow weirs were constructed to assist in the
dewatering of the marsh creation disposal area and to create
fringe marsh with the overflow. The dredged slurry has been
placed between elevations 2.03 NAVD 88 to 2.71 NAVD 88.

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This project is located in the Sabine National Wildlife
Refuge, west of LA Highway 27, in large, open water areas
west of Brown’s Lake in Cameron Parish, Louisiana.

The Sabine Refuge Marsh Creation Project was originally
approved as part of the Project Priority List 8 in 1999. The
project was later broken into 5 cycles. In 2004, additional
funds for engineering and design and construction were
approved for Cycle III. The placement of the dredged
material has been completed. Degradation of the retention
dikes is ongoing and expected to be completed soon.

This project is on Priority Project List (PPL) 8.

The Sabine Refuge Marsh Creation Cycle III’s sponsors include:

Sabine Refuge Marsh Creation Cycle II

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The project area is experiencing marsh degradation due to
saltwater intrusion and freshwater loss. This has resulted
in the conversion of vegetated intermediate marsh to large
shallow open water areas. Salinity migrates into the region
from the Calcasieu River. Southeast winds push saline
waters into the project area through canals and bayous.
Wind driven waves cause further loss of the remaining marsh
fringe.

A permanent dredged material disposal pipeline, measuring
3.57 miles in length, will be constructed in Cycle II. The
pipeline will commence near Mile 13.2 of the Calcasieu
River Ship Channel and terminate at the northeastern corner
of the Sabine National Wildlife Refuge. Much of the right
of way required for the pipeline was previously impacted
by the construction of a temporary pipeline used during the
construction of Cycle I. The pipeline is to be used for future
marsh creation projects in conjunction with the U.S. Army
Corps of Engineers maintenance dredging of the Calcasieu
River Ship Channel.

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The project is located on the
Sabine National Wildlife Refuge, west of Highway 27, in
large open water areas northeast of Brown’s Lake.

The Sabine Refuge Marsh Creation Project was originally
approved as part of the Project Priority List 8 in 1999. The
project was later broken into 5 cycles. In 2004, additional
funds for engineering and design and construction were
approved for Cycle II. The pipeline is constructed and will
be available for use during the 2011 maintenance dredging of
the Calcasieu River Ship Channel.

This project is on Priority Project List 8.

The Sabine Refuge Marsh Creation Cycle II’s sponsors include:

Sabine Refuge Marsh Creation Cycle I

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The project is intended to strategically create marsh in large,
open water areas to block wind-induced saltwater
introduction and freshwater loss. In addition, it will increase
nourishment in adjacent marshes while reducing open water
fetch (distance a wave can travel) and the erosion of marsh
fringe.

Cycle I constructed 214 acres of marsh within the shallow,
open water area within retention dikes. The perimeter of the
created marsh was planted with smooth cordgrass. Dredged
slurry obtained from the Army Corps of Engineers’ dredging
of the Calcasieu River Ship Channel was placed in the
containment area.

Upon consolidation of the dredged material, the southern
containment dike was degraded and breached to allow for
water movement and restore the area to more natural
conditions. Prior to the placement of dredged material,
trenasses (small, man-made bayous) were constructed in the
project area. These trenasses facilitate natural conditions and
allow estuarine organisms to access the created marsh. This
project is part of five cycles over a 10-year period with each
cycle requiring individual construction approval.

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The Sabine Refuge Marsh Creation Project is located in the
Sabine National Wildlife Refuge, west of LA Highway 27, in
large, open water areas north and northwest of Brown’s Lake
in Cameron Parish, Louisiana.

Priority Project List 8 funded $5.9 million to complete
construction of a permanent pipeline and one cycle of marsh
creation. Engineering analyses at the time indicated that the
construction of a temporary pipeline would be more cost
effective. Therefore, a temporary pipeline was utilized for
Cycle I. However, further analysis determined that a
permanent pipeline would be advantageous. In 2004,
additional funds for engineering and design and construction
were approved for Cycles II and III. Funds for Cycle II
include the construction of a permanent dredged material
pipeline.

Construction of the Cycle I site was completed on February
26, 2002.

This project is on Priority Project List (PPL) 8.

The Sabine Refuge Marsh Creation Cycle I’s three sponsors include:

View more data on the CS-28-1 project or other projects on CWPPRA’s website.

Lost Lake Marsh Creation and Hydrologic Restoration

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Significant marsh loss has occurred between Lake Pagie and
Bayou DeCade to the point that little structural framework
remains separating those two waterbodies. Northeast of Lost
Lake, interior marsh breakup has resulted in large, interior
ponds where wind/wave energy continues to result in marsh
loss. West of Lost Lake, interior breakup has occurred as
a result of ponding and the periodic entrapment of higher
salinity waters during storm events.

Approximately 465 acres of marsh will be created between
Lake Pagie and Bayou DeCade, north of Bayou DeCade,
and along the northwestern Lost Lake shoreline. Marsh
creation will restore/protect some key features of structural
framework (i.e., lake rim and bayou bank) within the area.
Borrow material will be taken from within Lost Lake and
pumped via a hydraulic dredge into the marsh creation sites.
Tidal creeks will be constructed within the marsh creation
cells to ensure tidal connectivity and prevent ponding within
the created marsh. In addition, 30,000 linear feet (22 acres)
of terraces will be constructed to reduce fetch in an area of
deteriorated marsh north of Bayou DeCade.
Two fixed-crest weirs along Carencro Bayou will be replaced
with variable-crest structures. At certain times of the year,
Carencro Bayou is an excellent source of fresh water and
sediments from the Atchafalaya River/Four League Bay
system. However, delivery of that water into the marshes
west of Lost Lake is limited by fixed-crest weirs which limit
water exchange. Installing structures with bays/gates will
increase freshwater and sediment delivery. In addition, two
fixed-crest weirs near Rice Bayou will be replaced with
variable-crest structures to provide flow-through conditions
in the system (i.e., water enters the system from Carencro
Bayou and exits through the structures near Rice Bayou).
A similar structure will be installed along Little Carencro
Bayou to increase freshwater and sediment delivery into the
marshes north of Lost Lake.

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The project is located in the Terrebonne Basin, Terrebonne
Parish, near the vicinity of Lost Lake.

This project is on Project Priority List (PPL) 19.

The Lost Lake Marsh Creation and Hydrologic Restoration project sponsors include:

Keep up with this project and other CWPPRA projects on the project page.

LaBranche East Marsh Creation

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Dredging of access and flotation canals for the construction
of I-10 and the Illinois Central Railroad resulted in increased
salinity and altered hydrology in the area that exacerbated
the conversion of wetland vegetation into shallow open
water bodies.

The project’s primary goal is to restore marsh that has been
converted to open water. Project implementation will result
in an increase of wildlife and fisheries habitat, acreage and
diversity, along with improving water quality. In addition,
the project will provide a storm buffer protection to I-10, the
region’s primary westward hurricane evacuation route, and
complement hurricane protection measures in the area.
Project features consist of the creation of 729 acres of marsh
and the nourishment of 202 acres of existing marsh using
dedicated dredging from Lake Pontchartrain. In addition,
10,000 linear feet of tidal creeks will be created. The marsh
creation area will have a target elevation the same as average
healthy marsh for this region. Plans are to place the dredge
material in the target area with the use of low level, noncontinuous
retention dikes along the edge of the project area
allowing overtopping of material to nourish the marsh fringe.
Vegetative plantings will be utilized in the areas deemed
most critical by the project team. Successful wetland
restoration in the immediate area (PO-17) clearly
demonstrates the suitability and stability of soil and material
availability from a sustainable borrow area.

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The project features are located between Lake Pontchartrain
and I-10 in St. Charles Parish, Louisiana. It is bounded on
the west by the Fall Canal and the Bayou LaBranche
Wetland Creation Project (PO-17) and the east by a pipeline
canal.

This project is on Project Priority List (PPL) 19.

The LaBranche East Marsh Creation project sponsors include:

Keep up with this project and other CWPPRA projects on the project page.

 

Cheniere Ronquille Barrier Island Restoration

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This area is undergoing shoreline erosion, interior wetland
loss, overwash, and breakup. The Gulf shoreline erosion rate
has doubled from 1988 to 2006. Project area marshes also
are being eroded at -11.8 ft/yr between 2003 to 2006 as well
as being converted to open water from internal breakup.

Restoration would expand the Gulf shoreline structural
integrity and associated protection by tying into two recently
constructed projects to the east and address one of the
remaining reaches of the Barataria/Plaquemines shoreline.
The design includes fill for a beach and dune plus 20-years
of advanced maintenance fill, as well as fill for marsh
creation/nourishment. The location of the type and amount
of sediment needed to construct this project already has been
identified under the East Grand Terre Project that is presently
under construction. Approximately 127 acres of beach/dune
fill would be constructed and approximately 259 acres of
marsh creation/nourishment would be constructed. Intensive
dune plantings would be conducted by seeding and installing
approved nursery stock. About half of the
marsh platform would be planted with cordgrass and
portions of the dune, swale, and marsh would be planted
with appropriate woody species. Containment dikes would
be breached no later than year three to allow tidal exchange
with the created marsh.

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The project is located in Region 2, within the Barataria Basin
portion of Plaquemines Parish.

This project is on Project Priority List (PPL) 19.

The Cheniere Ronquille Barrier Island Restoration project sponsors include:

Keep up with this project and other CWPPRA projects on the project page.