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.

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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.

 

Terrebonne Bay Marsh Creation-Nourishment

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Emergent marshes north of Terrebonne Bay have been
eroding as fast or faster than almost any other marshes
along coastal Louisiana. As these marshes convert to
shallow open water, the tidal prism will increase which will
in turn increase the frequency and duration of tides north
of Terrebonne Bay. This increasing tidal prism is likely
to increase the future interior marsh loss rates for those
marshes directly north of Terrebonne Bay. These marshes are
important for their habitat values as well as serving to slow
the progress of highly saline waters that threaten the lower
salinity marshes north and west of Madison Bay and in the
Lake Boudreaux basin. The
continued loss of these marshes has directly contributed to
the ongoing flooding problems of many communities along
Bayou Terrebonne including the town of Montegut.

The primary goal of this project is to fill shallow open water
areas and nourish marshes north of Terrebonne Bay/Lake
Barre thereby reducing the tidal prism north of Terrebonne
Bay and
interior land loss from tidal scouring. Specific Goals: 1)
Create 365 acres of intertidal marsh in shallow open water
and nourish 299 acres of fragmented marsh within the
project area reducing
water exchange between Terrebonne Bay and interior lakes
during tidal and small storm events. 2) Reduce erosion along
16,000 ft of the northern Terrebonne Bay shoreline.

The proposed features of this project consist of filling
approximately 365 acres of shallow open water and
nourishing approximately 299 acres of very low or
fragmented marsh with material hydraulically dredged from
Terrebonne Bay/Lake Barre. Containment dikes will be
degraded/gapped within 3 years of construction to allow
for greater tidal and estuarine organism access. This project
could be one part of a phased comprehensive plan to protect
the northern shoreline of Terrebonne Bay and the interior
marshes from further erosion and reduce the tidal prism.
The project would result in approximately 353 net acres of
marsh over the 20-year project life.

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This project is located in Region 3, Terrebonne Basin,
Terrebonne Parish, along the northern shoreline of Lake
Barre/Terrebonne Bay near Bayou Terrebonne continuing
east a short distance past Bayou Chitique.

This project is on Project Priority List (PPL) 20.

The Terrebonne Bay Marsh Creation-Nourishment project sponsors include:

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

 

Cameron-Creole Watershed Grand Bayou Marsh Creation

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Approximately 14,390 acres (32%) of the Cameron-Creole
Watershed Project (CCWP) marshes were lost to open water
from 1932 to 1990 at an average loss rate of 248 acres/year
(0.55 percent/year) due to subsidence and saltwater intrusion
from the Calcasieu Ship Channel. The
CCWP was implemented by the NRCS in 1989 to reduce
saltwater intrusion and stimulate restoration through
revegetation. Hurricanes Rita and Ike in 2005 and 2008
breached the watershed levee scouring the marsh and
allowing higher Calcasieu Lake salinities to enter the
watershed causing more land loss. The Calcasieu-Sabine
Basin lost 28 square miles (17,920 acres) (4.4%) as a result
of Hurricane Rita (Barras et al. 2006). Land loss is estimated
to be 1.33 percent/year based on USGS data from 1985 to
2009 within the extended project boundary.

Project goals include restoring and nourishing hurricane-scoured
marsh in the Cameron Prairie National Wildlife
Refuge and adjacent brackish marshes of the Calcasieu Lake
estuary. Approximately 3 million cubic yards of material
would be dredged from a borrow site proposed in Calcasieu
Lake and placed into two marsh creation areas north of
Grand Bayou to restore 609 acres and nourish approximately
7 acres of brackish marsh. The borrow site would be
designed to avoid and minimize impacts to oysters and other
sensitive aquatic habitat. Tidal creeks would be constructed
prior to placement of dredge material and retention levees
would be gapped to support estuarine fisheries access and
to achieve a functional marsh. The project would result in
approximately 534 net acres of brackish marsh over the 20-
year project life.

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This project is located in Region 4, Calcasieu-Sabine Basin,
Cameron Parish, 6 miles northeast from Cameron, LA, on
the Cameron Prairie NWR and Miami Corporation property
north of Grand Bayou.

This project is on Project Priority List (PPL) 20.

The Cameron-Creole Watershed Grand Bayou Marsh Creation sponsors include:

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

 

Bayou Bonfouca Marsh Creation

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The marsh in this area was fairly stable prior to Hurricane
Katrina in August 2005. There was extensive damage to the
marsh along the north shore of Lake Pontchartrain and
especially localized in the marshes near Bayou Bonfouca
when the storm surge removed many acres of marsh. Marsh
loss rates should increase in the marsh surrounding these
newly created open water areas due to an increase in wind
driven fetch. Within the project area, the Lake Pontchartrain
shoreline erosion rates seem to be very low. Currently, there
is one large breach and several smaller ones in the Lake
Pontchartrain shoreline, with many more breaches seemingly
imminent. These breaches provide direct connection between
the fresher interior marshes and higher saline waters of Lake
Pontchartrain. The breaches in the bankline should be filled
before they grow to become a major exchange point causing
an increase in interior loss rates.

The primary goal of the project is to create 533 acres and
nourish 42 acres of low salinity brackish marsh in open
water areas adjacent to Bayou Bonfouca with sediment
pumped from Lake Pontchartrain.
This project would consist of placing sediment, hydraulically
dredged from Lake Pontchartrain, in open water sites to a
height of +1.2 NAVD 88 to create 458 acres and nourish
approximately 133 acres of marsh. Several historic marsh
ponds have been identified and would be restored. Tidal
creeks are also proposed to connect these ponds to facilitate
water exchange and fisheries access. Containment dikes
would be sufficiently gapped or degraded to allow for
fisheries access no later than three years post construction.

The project would result in approximately 424 net acres of
intermediate marsh over the 20-year project life.

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This project is located in Region 1, Pontchartrain Basin, St.
Tammany Parish. Parts of the project are located within Big
Branch Marsh National Wildlife Refuge adjacent to Bayou
Bonfouca.

This project is on Project Priority List (PPL) 20.

The Bayou Bonfouca Marsh Creation project sponsors include:

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

Kelso Bayou Marsh Creation

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The most significant environmental problem affecting the
marshes in this area is deterioration and conversion to open
water. Marsh loss has and continues to occur as a result
of salt water intrusion and sediment export (erosion). The
construction of the Calcasieu Ship Channel and the Gulf
Intracoastal Waterway greatly increased the efficiency
of water exchange through Calcasieu Pass. Freshwater
retention was consequently reduced and salt water is able
to enter interior marshes and penetrate further north and
west. Project-area marshes are connected to the navigation
channels through a network of canals and bayous including
Kelso Bayou and Alkali Ditch. Unvegetated substrate
is vulnerable to increased tidal exchange and immense
quantities of organic substrate are being exported.
Recent marsh loss and scouring at the mouth of Kelso
Bayou from impacts related to Hurricanes Rita and Ike allow
increased salt water intrusion, tidal exchange, and storm
surge impacts.

The goal of this project is to restore and protect
approximately 319 acres of critically important marsh
and the numerous functions provided by those areas. The
proposed project will restore a portion of the historic
meandering channel of Kelso Bayou and provide direct
protection to Louisiana State Highway 27, the region’s only
northward hurricane evacuation route. Project features
include creating/nourishing 319 acres of marsh, 3,200 linear
feet of shoreline protection, and rock armor at the mouth of
Kelso Bayou to prevent additional tidal scour.

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This project is located in Region 4, Calcasieu-Sabine Basin,
Cameron Parish. The project features are located in an area
south of the Gulf Intracoastal Waterway and just west of the
Calcasieu Ship Channel.

This project is on Project Priority List (PPL) 20.

The Kelso Bayou Marsh Creation project sponsors include:

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