Bayou Dupont Ridge Creation and Marsh Restoration (BA-48)

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Problems: 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. Land loss data provided by the U.S. Geological Survey indicates that loss was occurring at a rate of 1.7% per year prior to construction. The natural limits of Bayou Dupont were difficult to determine in some areas because land loss was causing a merge of the bayou to adjacent water bodies. Natural tidal flow and drainage of patterns that once existed through the bayou were circumvented by the increasing area of open water.

Restoration Strategy: Project goals included: 1) creating and nourishing approximately 390 acres of marsh through sediment pipeline delivery from the Mississippi River; and   2) creating over two miles of ridge (10.5 acres of ridge habitat) along a portion of the southwestern shoreline of Bayou Dupont. Sediment from the river was hydraulically pumped to the project site to construct both the marsh and ridge features and additional material was dredged from Bayou Dupont to cover the ridge. The ridge is designed to mimic the configuration of other natural ridges within the watershed, and includes a constructed elevation conducive for the growth of native vegetation such as live oak, hackberry, and yaupon. The ridge is helping to redefine the limits of Bayou Dupont and reestablish the natural bank that once flanked the bayou and  protected adjacent marshes.

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Location: This project is located within the Barataria Basin in Jefferson and Plaquemines Parishes. The marsh creation area is located along Bayou Dupont southeast of the waterbody known as the Pen.

Progress to Date: Construction began in the Fall of 2014 in conjunction with the Mississippi River Long Distance Sediment Pipeline Project (BA-43EB) and Bayou Dupont Sediment Delivery-Marsh Creation #3 (BA-164). Construction of the Bayou Dupont (BA-48) portion was completed in fall of 2015.

This project is on Priority Project List 17.

Measuring Water Quality

Many wetlands of Louisiana receive their freshwater input from the Mississippi river, whose watershed drains approximately 40% of the United States’ waterways. [1] Pollutants get into the river from nonpoint sources, which are things like agricultural runoff, urban runoff from roads and sewage, or precipitation of atmospheric compounds, and thus they are spread into Louisiana’s wetlands.[2] Excessive pollutants deteriorate wetlands because they kill vital plants and animals in the ecosystem, which has feedback onto other species. Before interfering with anything in an ecosystem, we need to understand how the ecosystem functions.

Water quality plays a huge role in keeping wetlands healthy. The term “water quality” refers to several characteristics of a body of water, including salinity, nutrient concentration, turbidity, and dissolved oxygen [3]. These factors contribute to how well individuals can live and grow in the ecosystem associated with that body of water. For example, some plants and animals have a strong preference for either high or low salinity (See Salinity Stress Tolerance article), some prefer higher water levels (see Flooding and Hypoxia article), and some can live in many combinations of conditions.

Turbidity is a measure of how much suspended sediment is in the water column. Higher turbidity causes less light to penetrate to the deeper layers, so highly turbid waters often have less submerged aquatic vegetation. Turbidity can be measured with a Secchi disk or Secchi tube. Dissolved oxygen is important to aquatic plants because they still need to exchange oxygen to carry out their metabolic processes. Dissolved oxygen is measured by either luminescence sensors or electrode oxidation. [4] Many of the instruments that measure different aspects of water quality are combined into a Multiparameter Water Quality Sonde to get multiple measurements from the same sample of water. More information on specific procedures and equipment for measuring water quality can be found at https://www.fondriest.com/environmental-measurements/equipment/measuring-water-quality/.

Measuring water quality as a way of determining wetland health is important to many CWPPRA project locations. Measurements allow ecologists to determine any potential risks or threats from developing a project to the integrity of site’s established ecosystem. Fragile ecosystems can be drastically affected by constructing a project because the projects are likely to alter hydrology, salinity, and may introduce conditions that residents cannot survive. Forming a profile of water quality helps to predict the project’s positive and negative outcomes, and to predict the success and longevity of the project.

 

[1] https://www.nps.gov/miss/riverfacts.htm

[2] https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution

[3] https://www.fondriest.com/environmental-measurements/parameters/water-quality/

[4] https://www.ysi.com/parameters/dissolved-oxygen

Featured image from https://phys.org/news/2017-01-technique-quickly-salt-marsh-vulnerability.html

South Lake Lery Shoreline & Marsh Restoration (BS-16)

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Reasons for Restoration:

According to USGS-land loss analysis, much of the southern and western shorelines of Lake Lery and the surrounding wetlands were heavily damaged in 2005 by Hurricane Katrina. In the years following this storm, wind induced waves within the lake have begun to cause further damage to the lake’s shorelines. Currently the shorelines have become so damaged that the interior emergent marshes that are still intact are being exposed to the damaging waves. This has caused an increased loss of emergent marsh habitat. Even with the benefits of the Caernarvon Diversion Structure, without some type of restoration in this area, these marshes may not be able to fully recover.

Restoration Strategy:

This is a marsh creation and shoreline restoration project. The marsh creation aspect of the project will have a hydraulic dredge extract material from the Lake Lery water bottom and pump that material into contained marsh creation cells located south and west of the southern and western Lake Lery shorelines. This will create and/or nourish approximately 642 acres of intertidal intermediate marsh. The shoreline restoration component of the project will  have a barge-mounted dragline excavating material from the bottom of Lake Lery and placing that material along the southern and western shorelines. This restored shoreline will have a 50 foot crown width and be built to a height considered high intertidal marsh.

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Progress to Date:
This project received Phase II funding in January 2012. Construction began in the spring of 2015 and is expected to be complete in the summer of 2018. All marsh creation is complete. Earthwork and vegetative plantings associated with the lake rim embankments are complete. There are ongoing discussions regarding erosion concerns along lake rim embankments.
This Project is on Project Priority List 17.

The Sponsors for this Project include:

sponsors_1.pngFederal Sponsor: U.S. Fish and Wildlife Service

Local Sponsor: CPRA

 

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:

 

The People of Louisiana’s Coastal Wetlands

The Coastal Wetlands Planning, Protection and Restoration Act leads the fight against Louisiana’s disappearing coast. The native people of coastal Louisiana are greatly worried about losing their homes, sources of livelihood, and culture if the lands they live on continue to disappear. Saltwater intrusion, marshes becoming open water, and the disappearance of barrier islands and protective wetlands are a few of the challenges facing coastal communities. For centuries, marshes have served as home to numerous people: American Indian tribes, Vietnamese, Croatian Americans, and other groups. All of these coastal residents are familiar with the hardship of living in an area frequented by natural disasters. Most coastal residents have chosen to stay on their lands to defend and protect the ecosystem despite the extreme risks. Without the hard work and effort of diligent landowners and organizations like CWPPRA, coastal Louisiana would be vanishing at a much faster rate.

You can read Watermarks #48 People of the Coastal Wetlands to learn more about this topic.

Wetlands and Waterfowl

At this time of year in Louisiana, you are sure to see early morning waterfowl hunters dressed in their best camouflage. Louisiana sits on the Mississippi Flyway, North America’s most heavily-used migration corridor for waterfowl. Louisiana’s coastal wetlands provide habitat for more than five million migratory waterfowl, approximately half of the wintering duck population of the Mississippi Flyway. The coastal marshes of Louisiana provide habitat to mottled ducks, wood ducks, redheads, and pintails, just to name a few species. These waterfowl species can be spotted in coastal marshes, flooded timbers, flooded grain fields, and other wetland areas. Grab your waders, shot gun, and a duck call, and take advantage of Louisiana’s Sportsman’s Paradise.

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It is critical to protect the coastal marshes and wetlands within the state for Louisiana to remain the front runner for waterfowl hunting. CWPPRA projects are aimed at protecting and restoring Louisiana’s coastal wetlands, ensuring that wildlife and the people who hunt them have the habitat they need.

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.