Marsh Island Hydrologic Restoration (TV-14)

banner_tv-14.fwReasons to Restore:

  • Natural erosion
  • Subsidence
  • Construction of navigation canals along the northeast shoreline of a Marsh Island.
  • Deterioration of the north rim of Lake Sand and the interior marshes.

Restoration Strategy:

  • Stabilizes the northeastern shoreline of Marsh Island.
  • Stabilizing the northern shoreline of Lake Sand.
  • Help restore the historic hydrology.
  • Construction of 7 closures for oil and gas canals at the northeast end of Marsh Island.
  • Protect the northeast shoreline with rock including the isolation of Lake Sand from Vermilion Bay.

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[2]

Location:

This project is located in Iberia Parish, Louisiana, on the eastern portion of the Russell Sage Foundation Marsh Island State Wildlife Refuge and surrounding Lake Sand.

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Project Effectiveness [1]:

  • Effective at reducing water level variability within the northern portion of the project area
  • Water level variability did not increase in the project area as is did in R1 post-construction
  • Reducing erosion rates at the northeast shoreline was partially met
  • Reduced erosion in areas of applied rock dikes versus unprotected areas.
  • The steel sheet pile, rock rip-rap wingwall, and stone bank paving installed at each end of closure No. 5 proved to be successful in preventing erosion during a storm event.

Previous Progress [2]:

  • The monitoring plan was finalized in January 2000 following with further data collection.
  • Pre-construction and post-construction aerial photography were in the year 2000, and 2009 with future imagery analyses upcoming.
  • Water level, submerged aquatic vegetation and shoreline position and movement data were also collected to evaluate project effectiveness.

Progress to Date [1]:

  • Construction was completed in December 2001.
  • This is one of the three projects nearing the end of their 20 year lives.
  • The Task Force will vote on the Technical Committee’s recommendation on the path forward for the following projects [1]:

3 projects

This project is on Priority Project List (PPL) 6.

Project Sponsors Include:

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  CPRA_logo_sponsor                

Source:

[1] Mouledous, M. and Broussard, D. 2014. 2014 Operations, Maintenance, and Monitoring Report for Marsh Island Hydrologic Restoration. Coastal Protection and Restoration Authority (CPRA). Available:https://lacoast.gov/ocmc/MailContent.aspx?ID=10092 [May 22,2018].

[2] Marsh Island Hydrologic Restoration (TV-14) Land-Water Classification. 2009. Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA). Available: https://www.lacoast.gov/products/sab_net_pub_products/map/original/2011-02-0009.pdf [May 22, 2018].

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The Mississippi River Deltaic Cycle

Water flows downhill naturally and, over time, will make a river change from one path to another. As sediment moved and elevations changed over the last 7 millennia, the Mississippi River has emptied into several historic delta complexes: Maringouin, Teche, St. Bernard, Lafourche, Plaquemines-Balize, and Atchafalaya. Each of the deltas built up part of Louisiana’s coast to what we see today, but now that natural process has been interrupted [1]. After the great Mississippi flood of 1927 that caused $1 billion worth of damages (almost $1 trillion in today’s dollars), the US Army Corps of Engineers built the world’s longest levee system under the Flood Control Act of 1928. The Levee system was constructed to reduce flood damages and allow for more control of the Mississippi [2].

Image 1: Historic Deltas of the Mississippi River

An unforeseen and unfavorable side effect to taming the river was that all the water is kept moving too quickly to deposit sediment, and now sediment is lost to the Gulf of Mexico rather than deposited into our coastal wetlands [3]. Our Louisiana coastline is dependent on new sediment to nourish wetland ecosystems. Without sediment delivery, there is no material for natural land gain or replenishment, which will continue to contribute to our retreating coastline. The solution is not as simple as removing the levee system, however, since so much of Louisiana is populated now, and removing the levees containing the Mississippi would displace millions of residents from their homes. Instead, CWPPRA and our partners in restoration use man-made systems to create marsh, nourish wetlands, and maintain hydrologic connectivity so that we can protect and restore Louisiana’s coast.

 

 

[1] https://en.wikipedia.org/wiki/Mississippi_River_Delta

[2] https://en.wikipedia.org/wiki/Great_Mississippi_Flood_of_1927

[3] http://mississippiriverdelta.org/our-coastal-crisis/wasted-sediment/

Image 1 from https://www.nationalgeographic.org/photo/miss-delta-formation/

Featured image from https://phys.org/news/2015-04-future-mississippi-delta.html

Black Bayou Culverts Hydrological Restoration (CS-29)

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The marsh within this area has been suffering from excessive water levels within the lakes subbasin that kills vegetation, prevents growth of desirable annual plant species, and contributes to shoreline erosion. Black Bayou offers a unique location in the basin where the water in the lakes subbasin and the outer, tidal waters are separated by only a narrow highway corridor.

Project components include installing ten 10 foot by 10 foot concrete box culverts in Black Bayou at the intersection of Louisiana Highway 384. The structure discharge will be in addition to the discharges provided by Calcasieu Locks, Schooner Bayou, and Catfish Point water control structures.

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The project features are located in southern Calcasieu Parish, Louisiana. The majority of the project area is located east of Calcasieu Lake and includes areas north of the Gulf Intracoastal Waterway and west of Grand Lake in Cameron Parish, Louisiana.

Construction has been completed.

This project is on Priority Project List 9.

Federal Sponsor: NRCS

Local Sponsor: CPRA

Audubon Zoo – Earth Fest

Environmental awareness is an important factor in protecting the earth, and the Audubon Institute understands that. With the help of Entergy, the Audubon Zoo has hosted Earth Fest for over twenty years to date, celebrating conservation and environment-friendly practices.

This past Saturday, March 24, CWPPRA was one of many organizations to be represented at Earth Fest along with Wetland Watchers, EnergySmart, Sea Grant, and many more. Each of these organizations brought educational activities to be enjoyed by children and adults alike, such as demonstrations of energy-saving appliances, composting, and beekeeping strategies. Participants could paint with produce from a local farmer’s market, learn about the similarities in bone structures between humans and manatees, and get their faces painted. When they were not busy visiting the zoo enclosures or talking to organizations, guests could enjoy a number of local food vendors or live performers at the pavilion, including Grammy-winning Lost Bayou Ramblers from south Louisiana.

CWPPRA Public Outreach spent the day handing out informational booklets about restoration projects, posters from the Protect Our Coast series, and activity books, as well as playing our popular “Wetland Jeopardy” game with any and all who were interested. Many eager and interested visitors participated in the Earth Fest Earth Quest, a game that led them to ask questions to appropriate organizations in exchange for a stamp. 10 stamps earned them a prize of a young plant to take home and care for. Earth Fest had a wide range of attractions that hopefully inspired all visitors to be more conscious of environmental issues and to help in the efforts to live for a healthier tomorrow.

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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.

Wetlands around the World

Let’s take a brief glance at wetlands around the world. Wetlands exist in many climates and on every continent except Antarctica. Considered the most biologically diverse of all ecosystems, wetlands provide habitat for an array of water, land, and migratory bird species. The wetlands highlighted include swamps, bogs, marshes, estuaries, floodplains, lakes and many other types.

The Pantanal

The Pantanal is located in the heart of South America and is the world’s largest wetland that has not been significantly modified by humans. The Pantanal is often referred to as South America’s biggest biodiversity star stretching across Brazil, Bolivia, and Paraguay. Its complex system of marshlands, floodplains, lagoons and interconnected drainage lines is home to over 4,700 species of plants and animals. The array of life in the Pantanal relies on an annual flooding cycle. The cycle of waters rising and then receding through the dry season nurtures a biologically diverse group of plants and is essential to preserve a healthy ecosystem.

Camargue

The Camargue, also referred to as the Rhone River Delta, is an alluvial plain located in the Southeast of France. Roughly a third of the Camargue wetlands are either lakes or marsh. This wetland is one of the most highly rated places in Europe for birdwatching. The area is historically famous for the greater flamingo and Camargue’s horses. If you are enticed to visit the Camargue, be sure to look into horseback riding on this special breed of horses.

Kafue Flats

Located in central Zambia, the Kafue flats consist of a unique variety of wetland types. The landscape located along the Kafue River includes grasslands, lagoons, swamps and marshes. This wetland is extremely important to Zambia for hosting wildlife, fishing, sugarcane farming and the production of hydro-electric power. Within the Kafue National Park you can spot a number of safari camps and lodges that have brought new interest to the area and attract many tourists.

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Sundarbans

The meaning of “Sundarbans” is beautiful forests, which perfectly fits the name for the largest mangrove forest in the world. The region is also home to Sundari trees growing in salty coastal waters. These are a special kind of mangrove tree with roots called pneumatophores that emerge above the ground and aid in gaseous exchange. Along with serving as home to Sundari trees, this wetland region has possibly the largest population of Bengal tigers in the world. These tigers can be found swimming in the saline waters of this unique habitat in the same areas used by people.

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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.