Bayou Dupont Sediment Delivery – Marsh Creation and Terracing

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Wetlands in the Barataria Basin were historically nourished
by the fresh water, sediment and nutrients delivered by
the Mississippi River and its many distributary channels.
These sediment and nutrient inputs ceased following the
creation of levees along the lower river for flood control and
navigation. In addition, the construction of numerous oil and
gas canals along with subsurface oil and gas withdrawal has
exacerbated wetland loss in the area. From 1932 to 1990, the
Barataria Basin lost over 245,000 acres of marsh. From 1978
to 1990, the area experienced the highest rate of wetland loss
in coastal Louisiana.

The primary goal of this project is to create and nourish
approximately 144 acres of emergent intermediate marsh
using sediment from the Mississippi River, and constructing
9,679 linear feet of terraces. The proposed project includes
dredging sediment from the Mississippi River for marsh
creation by pumping the sediment via pipeline into an area of
open water and broken marsh. The proximity of the project
to the Mississippi River provides a prime opportunity to
utilize this renewable river sediment resource. The strategy
includes utilizing the access route and infrastructure
previously put into place for the BA-39 project. This project
will complement existing restoration projects in the area.

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CWPPRA Region 2, Barataria Basin, Jefferson and
Plaquemines Parishes. The general project area is about 10
miles south of Belle Chasse, LA and is west of LA Hwy
23 and north of the Myrtle Grove Marina. The project
is immediately adjacent to the completed CWPPRA
Mississippi River Sediment Delivery System – Bayou
Dupont (BA-39) project.

The project was approved for engineering and design at the
January 24, 2013 Task Force meeting. The E&D was
completed in the fall of 2014 and sponsors requested phase
2 funding at the January 22, 2015 Task Force meeting,
however, there was insufficient money available to fund
the entire project. In order to take advantage of the existing
mobilization of the Long Distance Sediment Pipeline
(LDSP) Project, the sponsors proposed to reduce the scope
of the project to fit within the available CWPPRA funding.
The Task Force approved the reduced scope Phase 2 funding
request at the May 14, 2015, Task Force meeting. The asbuilt
project features include 144 acres of marsh creation and
9,679 linear feet of terracing.

In addition, CPRA increased the marsh creation feature of
the project by utilizing contingency funding left over from
BA-43, thereby increasing the total marsh creation in the
area to an estimated 296 acres. Construction started in April
2016, and marsh creation was completed in November
2016. Terracing was completed in June 2017, and vegetative
plantings for the terraces are scheduled for the spring of
2018.

This project is on Priority Project List (PPL) 22.

The Bayou Dupont Sediment Delivery – Marsh Creation and Terracing sponsors include:

 

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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:

 

Cameron-Creole Freshwater Introduction

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Virtually all of the project area marshes have experienced
increased tidal exchange, saltwater intrusion, and reduced
freshwater retention resulting from hydrologic changes
associated with the Calcasieu Ship Channel and the GIWW.
In addition, thousands of acres of marsh were damaged by
Hurricane Rita and again, more recently, by Hurricane Ike.
Because of man-made alterations to the hydrology, it is
unlikely that those marshes will recover without
comprehensive restoration efforts. The Cameron-Creole
Watershed Project has successfully reduced salinities and
increased marsh productivity. However, the area remains
disconnected from freshwater, sediments, and nutrients
available from the GIWW.

The freshwater introduction project would restore the
function, value, and sustainability to approximately 22,247
acres of marsh and open water by improving hydrologic
conditions via freshwater input and increasing organic
productivity.

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The project area is located on the east side of Calcasieu Lake
and west of Gibbstown Bridge and Highway 27.

This project is on Project Priority List (PPL) 18.

The Cameron-Creole Freshwater Introduction sponsors include:

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

Classification of Marshes

Marsh is a type of wetland that is continually flooded with water. Marshes can be found both on the coast or inland. Most of the water present is due to surface water; however, some groundwater also fills this wetland area.

Marshes can be divided into two main categories: non-tidal and tidal.

Non-tidal Marshes:

  • Most widely distributed and productive wetlands in North America
  • Occur along the boundaries of lakes, streams, rivers and ponds
  • Mostly freshwater, but some are brackish or alkaline
  • Beneath these wetlands lie highly organic soils
  • You might spot cattails, lily pads, reeds, and an array of waterfowl in this wetland
  • Alleviate flood damage and filter surface runoff

Tidal Marshes:

  • Found along protected coastlines and impacted by ocean tides
  • Present along the Gulf of Mexico
  • Some are freshwater or brackish, mostly saline
  • Provide shelter and nesting sites for migratory fowl
  • Covered by smooth cordgrass, spike grass, and salt meadow rush
  • Slow down shoreline erosion

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Freshwater Wetlands

Freshwater habitats come in many forms ranging from glaciers to lakes, rivers, and wetlands. These freshwater ecosystems represent less than one percent of the planet’s surface while supporting over 100,000 species including but not limited to fish, frogs, worms, crawfish, and birds and mammals nesting and feeding in wetland vegetation. While serving as habitat for a large number of animals, freshwater wetlands are also home to a variety of plant types. Cattails are a common sight around freshwater lakes and marshes and help in maintaining a healthy ecosystem by filtering runoff as it flows into lakes and serving as a protectant against shoreline erosion. Floating plants, such as duckweed, are a favorite food for many ducks and geese that populate the area.

Freshwater wetlands may stay wet year-round or evaporate during the dry season. Freshwater habitats are some of the most endangered habitats in the world. Human development, agriculture, and pollution are leading factors that put the availability of freshwater at risk. Saltwater intrusion is another underlying factor interrupting the natural conditions of water quality. These impacts have extreme consequences for our freshwater biodiversity, economy, and our well-being. Louisiana’s freshwater wetlands along the coast and other areas are disappearing at a high rate. The Coastal Wetlands Planning, Protection, and Restoration Act implements projects in an effort to preserve freshwater ecosystems.

 

Wetland Crustacean

Crawfish

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A well-known part of Louisiana’s culture is the state’s unique cuisine and the celebrations and gatherings which surround it. During late winter and spring, Louisiana’s state crustacean, the crawfish, is at the heart of many celebrations. The crawfish, an easily recognizable icon in Louisiana’s rich history and economy, has made an important impact on the state.

The two species of crawfish harvested for commercial use are the Red Crawfish (Procambarus clarki) and White or River Crawfish (Procambarus acutus). While looking very similar, the White Crawfish has one slender and one large pincer and inhabits deeper bodies of water when compared with the Red Crawfish which has two large pincers and is commonly found in bayous, ditches, and swamps. Although the characteristic habitat location varies among the two species, most harvested boil sacks contain both Red and White Crawfish. Both species’ living environments surround wetlands and coastal regions where the aquaculture industry has skyrocketed and continues to thrive.

Crawfish are important to Louisiana’s economy, and more than 7,000 people depend directly or indirectly on the crawfish industry. Crawfish provide an abundance of jobs as they are caught by fishermen, sold, processed, distributed, and shipped, and then finally make their way to customers or onto a restaurant table. Technology has advanced the methods of harvest such that crawfish farming has developed into the largest freshwater crustacean aquaculture industry in the United States. Louisiana leads the nation in crawfish production with nearly 800 commercial fishermen harvesting from wetlands like the Atchafalaya Basin and more than 1,600 farmers harvesting in some 111,000 acres of ponds. The total impact on the Louisiana economy exceeds $300 million annually, with a combined annual yield ranging from 120-150 million pounds.

Eat more crawfish, cher! 

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