New Orleans Landbridge Shoreline Stabilization & Marsh Creation (PO-169)

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Since 1956, approximately 110 acres of marsh has been lost along
the east shore of Lake Pontchartrain between Hospital Road and
the Greens Ditch. One of the greatest influences of marsh loss in
the area can be attributed to tropical storm impacts. Wetland losses
were accelerated by winds and storm surge caused by Hurricane
Katrina, which converted approximately 70 acres of interior marsh
to open water. Stabilizing the shoreline and protecting the
remaining marsh would protect natural coastal resources dependent
on this important estuarine lake, communities that thrive on those
resources, the Fort Pike State Historical Site, and infrastructure
including U.S. Highway 90. USGS land change analysis
determined a loss rate of -0.35% per year for the 1984 -2011
period of analysis. Subsidence in this unit is relatively low and is
estimated at 0-1foot/century (Coast 2050).

Lake Pontchartrain supports a large number of wintering
waterfowl. Various gulls, terns, herons, egrets, and rails can be
found using habitats associated with Lake Pontchartrain, which has
been designated as an Important Bird Area by the American Bird
Conservancy. Restoring these marshes will protect the Orleans
Landbridge and will help to protect fish and wildlife trust resources
dependent on these marsh habitats, particularly at-risk species and
species of conservation concern such as the black rail, reddish
egret, brown pelican, mottled duck, seaside sparrow, king rail, and
the Louisiana eyed silkmoth.

Borrow material will be dredged from areas within Lakes St.
Catherine and Pontchartrain to create 169 acres and nourish 102
acres of brackish marsh. Containment dikes will be constructed
around four marsh creation areas to retain sediment during
pumping. The lake shorelines will be enhanced with an earthen
berm to add additional protection from wind induced wave fetch.
Containment dikes that are not functioning as shoreline
enhancement will be degraded and/or gapped. Vegetative plantings are
proposed including five rows along the crown and two rows
along the front slope of the shoreline protection berm, as well as
within the marsh platform area.

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The project is located in Region 1, Pontchartrain Basin,
Orleans Parish, flanking U.S. Highway 90 along the east shore of
Lake Pontchartrain and areas surrounding Lake St. Catherine.

This project was approved for Phase I Engineering and Design in
January 2015.

This project is on Priority Project List (PPL) 24.

The New Orleans Landbridge Shoreline Stabilization & Marsh Creation sponsors include:

 

 

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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.

Wetland Soils

World Soil Day was officially celebrated on December 5th. This day was created in an effort to share the importance of healthy soil and advocate for the sustainable management of soil resources. Wetland soils, also known as hydric soils, are permanently or seasonally saturated by water and develop anaerobic conditions. Soils’ ability to store surface or ground water and bio-geochemical processes are critical to wetland function and maintaining a healthy ecosystem. Wetland scientists spend a great deal of their time performing soil surveys. Different wetland types feature different soil types. Soils should be evaluated for the presence of pesticides or dangerous elements that could cause damage to the vegetation and animals of that wetland site.

This day was created in an effort to focus on the importance of soil as a critical component of natural systems and as a vital contributor to human well-being.

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Interesting fact:

  • 95% of our food comes from the soil

 

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.

 

The Pantanal — The Largest Wetland in the World

Located in the heart of South America is the world’s largest wetland that has not been significantly modified by humans, the Pantanal. The Pantanal is often referred to as South America’s biggest biodiversity star. However, it is also one of the continent’s best-kept secrets, often overshadowed by the Amazon Rainforest. This massive wetland covers an area estimated at 75,000 square miles across Bolivia, Paraguay, and (mostly) Brazil. The Pantanal is home to over 4,700 species of plants and animals.

The array of life in the Pantanal relies on an annual flooding cycle. When it rains, about 80 percent of the floodplain is submerged underwater; throughout the dry season the water lessens. This process is essential to nurturing a biologically diverse collection of plants and providing nutrients that the wetlands need to flourish. An area that is the size of Belgium, Switzerland, Holland, and Portugal combined needs a lot of water to guarantee that it continues to flood and a healthy ecosystem is preserved. The quality of the water is also important to maintaining a nourishing environment. Recently, human activity has been threatening this precious wetland. The Pantanal is threatened by intensive farming, deforestation, and pollution. Few signs of this situation improving are shown, and environmental issues are difficult to resolve quickly. Conservation of the biodiversity and natural resources of the Pantanal is essential.

Coastwide Vegetative Planting

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The coastal restoration community has long recognized the benefits of vegetative plantings in restoration. Many marsh creation and most terracing projects require plantings to insure success. Coastal shoreline plantings have also proven to be very effective and some have demonstrated the ability to not only stop shoreline erosion but to facilitate accretion, the process of increasing sediments. Recent hurricane events have exposed a need to have a mechanism in place where large-scale planting efforts can be deployed in a timely manner to specifically targeted areas of need, anywhere along the coast. Although the CWPPRA program can fund specific large-scale planting projects, the normal program cycle for individual projects can delay needed restoration plantings for a number of years.

The goals of this project are to facilitate a consistent and responsive planting effort in coastal Louisiana that is flexible enough to routinely plant on a large scale and be able to rapidly respond to critical areas of need following storm or other damaging events. This project set up an advisory panel consisting of representatives from various state and federal agencies who would assist in the selection of projects for funding. The project also set up a mechanism by which project nominations would be submitted for consideration. The equivalent of 90 acres of interior marsh and 40,000 linear feet of coastal shoreline will be planted per year over a 10 year period to effectively create/protect a total of 779 net acres of marsh over the 20-year project life.

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The project features are located in the coastal zone of Louisiana.

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

The Coastwide Vegetative Planting project sponsors include:

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

 

Wetland Plants

Plants are a vital piece of healthy and sustainable wetland ecosystems. Plants are the base of the food chain and can build new layers of organic material on top of wetlands which helps them keep pace with subsidence and rising waters. Wetland vegetation reduces erosion primarily by dampening and absorbing wave and current energy and by binding and stabilizing the soil with roots. Coastal wetland plant species are indicators of soil and hydrologic conditions. The amount and salinity of water in an area influence which plants grow there. Scientists often classify Louisiana marshes into four types: fresh, intermediate, brackish, and saline.

The Coastal Wetlands Planning, Protection, and Restoration Act puts native wetland plant benefits to use through restoration techniques that include vegetative plantings. Vegetative planting projects are used both alone and in conjunction with barrier island restoration, marsh creation, shoreline protection, and sediment and nutrient trapping restoration techniques. These projects use flood-and salt-tolerant native marsh plants that will hold sediments together and stabilize the soil with their roots as they become established in a new area.

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BA-38 Barataria Barrier Island Complex Project: Pelican Island and Pass La Mer to Chaland Pass Restoration