Fritchie Marsh Creation and Terracing

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A significant portion of the Fritchie Marsh was lost due to
Hurricane Katrina. Post storm shallow open water areas
dominate the landscape which limits the effectiveness of the
PO-06 CWPRRA project. Wetlands in the project vicinity
are being lost at the rate -1.09%/year based on USGS
data from 1985 to 2015. These marshes cannot recover
without replacement of lost sediment, which is critical if the
northshore marshes are to be sustained.

Project goals include restoring and nourishing marsh.
Specific goals of the project are: 1) create approximately 291
acres of marsh; 2) nourish approximately 49 acres of existing
marsh; and 3) construct about 36,610 feet of earthen terraces
or 26 emergent acres.

An alternative analysis was conducted leading to the
selection of features and configuration to compliment and
work synergistically with the existing PO-06 project and
planned mitigation and restoration projects in the Fritchie
Marsh. A robust engineering cost is included to evaluate
increasing the project size if costs allow or adjust the
layout, if needed during Phase 1. Approximately 2 million
cubic yards of material would be placed confined to restore
291 acres and nourish approximately 49 acres of brackish
marsh. Material would be dredged from a borrow site in
Lake Pontchartrain. The borrow site would be designed to
avoid and minimize impacts to aquatic habitat and existing
shorelines. Approximately 26 acres of earthen terraces would
be constructed within various locations totaling approximately
36,610 feet or 523 acres of terrace field. All containment
dikes would be gapped or degraded no later than three years
after construction to facilitate the development of tidal marsh
functions supportive of estuarine species. The terraces would
be planted as well as 50% of the created marsh acres to
expedite colonization and enhance stabilization.

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Region 1, Pontchartrain Basin, St. Tammany Parish, located
approximately three miles southeast of Slidell, Louisiana. A
substantial portion of the project is located on Big Branch
National Wildlife Refuge.

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

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

The Fritchie Marsh Creation and Terracing sponsors include:

 

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Mangroves in Winter

The recent cold weather in Louisiana may have been the end of the road for some plants as temperatures dipped into the teens and stayed below freezing for full days. The hibiscus in your garden may have survived because you gave it extra insulation, but what about marsh plants? Louisiana salt marshes are home to black mangroves (Avicennia germinans), but this represents the very northernmost part of their range. Of the three mangrove species found in the continental United States [red (Rhizophora mangle), black, and white (Laguncularia racemosa)], black mangroves are the most cold-hardy, but they are still sensitive to winter weather- they generally cannot establish above 28° N and S latitude because winters are too cold (a sliver of the Birdsfoot Delta is below 29° N, so we really are at their limit).

The three mangrove species are also different in their tolerances for other environmental conditions: red mangroves establish in the intertidal zone, while black and white mangroves are found at higher elevations, and white mangroves can colonize areas with little to no soil. In Florida where all three species occur, mangrove zones can be defined from the water extending inland and up in elevation .

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Red mangroves are found in the intertidal zone, while black and white mangroves establish at higher elevations. Graphic from the Florida Museum of Natural History at the University of Florida (https://www.floridamuseum.ufl.edu/southflorida/habitats/mangroves/zonation/)

Black mangroves are an important component of Louisiana salt marshes, providing habitat to a variety of species. The complex root systems trap and collect sediment, limiting erosion and maintaining land. Juvenile invertebrates and fish find shelter among the roots, while seabird chicks, such as brown pelicans and roseate spoonbills, are protected from high water events and predators up in the branches.

CWPPRA projects that nourish barrier islands and create new marsh habitat help maintain black mangrove populations by providing new land for the plants to colonize; in turn, the mangroves help the new land persist in the face of wind and wave energy.

South Grand Chenier Marsh Creation – Baker Tract

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Marshes within the Hog Bayou Watershed mapping unit are
stressed due to limited freshwater input and seasonal salinity
spikes exacerbated by construction of the Mermentau Ship
Channel. Other contributors to land loss in the area are
subsidence, compaction, and erosion of organic soils.
Currently, the project area is characterized as large, open
water with degraded areas of wetland vegetation and low
organic production. The dredging of the Mermentau Ship
Channel increased tidal amplitude and salt water intrusion
into the watershed.

The goal of the project is to create new wetland habitat,
restore degraded marsh, and reduce wave erosion of organic
soils. The project would promote the expansion of emergent
marsh and submerged aquatic vegetation throughout the
project area. Material dredged from the Gulf of Mexico will
be used to create and nourish approximately 420 acres of
marsh. Smooth cordgrass will be planted throughout the
area. To help facilitate estuarine fisheries access, constructed
retention levees will be degraded and approximately 11,756
linear feet of tidal creeks will be constructed.

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The project is located in planning Region 4, Mermentau
Basin in Cameron Parish within the Hog Bayou Watershed
Coast 2050 Mapping Unit. The mapping unit is bordered by
Lower Mud Lake to the west, the Gulf of Mexico to the
south, Rockefeller Refuge to the east, and Louisiana
Highway 82 to the north.

This project is on Priority Project List (PPL) 23.

The South Grand Chenier Marsh Creation – Baker Tract sponsors include:

 

CWPPRA Project Selection

          The planning process leading up to project selection includes the nomination of a project followed by development and evaluation of proposed projects based on engineering, environmental improvements, and economics.

          A general breakdown of CWPPRA Project Selection is as follows:

  • CWPPRA projects are brought to the Task Force by the public, local municipalities, state agencies, and federal partners.
  • In January and February, each year 10-20 projects from each of the four regions become Priority Project List (PPL) candidates.
  • Parish representatives then rank projects in each region, and by the end of the spring the Technical Committee selects 10 projects from the annual PPL candidate projects for further development.
  • Of these 10 candidate projects, the Technical Committee recommends 4 projects for the design phase (Phase I) at their December meeting.
  • The Task Force must approve the 4 projects for design at their next meeting in January.
  • Projects already in design can request approval to proceed to Phase II for construction, and the Technical Committee will recommend 1-4 of these to the Task Force. Ultimately, the Task Force approves 1-4 of the recommended projects for construction.
  • Following the Technical Committee’s meeting and PPL recommendations in December, the Task Force will meet to finalize the approved projects. This year’s Task Force meeting is scheduled for January 25th. 

          Stay up-to-date on the project selection for this year’s Priority Project List by visiting our website. You can read more about CWPPRA Project Selection in Understanding CWPPRA.

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Wetland Marshes

Marsh is a type of wetland that is continuously flooded with water. Emergent-soft stemmed vegetation is present in marsh due to the saturated soil conditions. In Louisiana, there are four types of wetland marsh: freshwater, intermediate, brackish, and salt. Marshes are classified according to the salinity of the water. The location of Louisiana marshes in relation to the Gulf of Mexico often directly correlates to the level of salt content in the water. Salinity also changes based upon rainfall, drainage, soil texture, vegetation, depth of water table, and freshwater inflow.

The salinity range for each marsh type is as follows:

  • Freshwater – 0 ppt (parts per thousand)
  • Intermediate – 0-5 ppt
  • Brackish – 5-15 ppt
  • Salt – 15 or greater ppt

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A wide variety of animals such as nutria, turtles, and many bird species can be spotted in the freshwater and intermediate marshes of Louisiana, as well as species of special concern like Louisiana black bears and Calcasieu painted crawfish. The exchange between freshwater and salt water is frequent in the state of Louisiana due to its close proximity to the Gulf of Mexico. An estuary is characterized by this mixture of freshwater and salt forming brackish water where many wetland species spend their juvenile lives. The estuaries of coastal Louisiana support economically important fisheries and provide important wildlife habitat. Crabs, fish, and shrimp are a few of the animals found in Louisiana’s salt marsh, and birds like brown pelicans and reddish egrets often nest in the shrubby vegetation bordering salt marshes. Each of these marsh types play a significant role. It is vital to keep these marshes healthy for them to maintain their value and support the people, plants, and animals of Louisiana.

 

 

Cole’s Bayou Marsh Restoration

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Project area wetlands are undergoing loss at -0.42 %/year
based on 1983 to 2011 USGS data from the extended
boundary. Wetland loss processes in this area include
subsidence/sediment deficit, interior ponding and pond
enlargement, and storm impacts resulting in rapid episodic
losses. In addition, significant interior marsh loss has
resulted from salt water intrusion and hydrologic changes
associated with increasing tidal influence. As hydrology in
this area has been modified, habitats have shifted to more of
a floatant marsh type, resulting in increased susceptibility to
tidal energy and storm damages. Habitat shifts and
hydrologic stress reduce marsh productivity, a critical
component of vertical accretion in wetlands.

The specific goals of the project are: 1) create 365 acres of
brackish marsh in recently formed shallow open water; 2)
nourish 53 acres of existing brackish marsh; and, 3) increase
freshwater and sediment inflow into interior wetlands by
improving project area hydrology.

This project aims to create 365 acres and nourish 53 acres of
brackish marsh via dedicated dredging with borrow from
nearby Vermilion Bay. Although Vermilion Bay is not
considered an “external” source of material, significant
sediment inflows into this area may result in some borrow
area infilling. Half of the marsh creation acres would be
planted. The project will encourage additional freshwater
nutrient and sediment inflow from Freshwater Bayou Canal
by dredging a portion of Cole’s Bayou along with the
installation of a series of culverts throughout the project
area.

The culverts located along the northern project boundary are
envisioned to allow the ingress of sediment, water, and
fisheries organisms into the semi-impounded project area,
but avoid backflow of water and potential loss of interior
marsh sediment (i.e., north to south flow only). The culverts
located along the southern project boundary are envisioned
to allow water to drain out of the marsh.

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This project is located in Region 3, Teche/Vermilion Basin,
Vermilion Parish, east of Freshwater Bayou Canal.

This project is on Priority Project List (PPL) 21.

The Cole’s Bayou Marsh Restoration sponsors include:

 

Wetland Vegetation

Wetland ecologists often refer to wetland vegetation as the foundation of coastal restoration. Native plants and vegetative plantings both provide significant benefits to wetlands. Wetland plants build and stabilize soil, create habitat, purify water, and shield infrastructure. These plants tend to accumulate the thick mud of marshes which prevents the soil from washing away. Animals that live in wetlands depend on plants or plant-eating animals for their food supply. Without wetland vegetation, the supply chain would self-destruct. By absorbing nutrients and chemicals from the water and sediment, plants reduce toxins and groundwater contamination. Wetland vegetation is key to preventing shoreline erosion and reducing storm surge which affects the coastal infrastructure.

The Coastal Wetlands Planning, Protection and Restoration Act funds a variety of wetland enhancement projects, such as vegetative planting. Vegetative planting is the process of planting by hand or aerial seeding to shore up eroding banks and jump-start plant colonization.

You can read more about CWPPRA Projects that use the vegetative planting restoration technique by clicking here.