Cameron Prairie National Wildlife Refuge Shoreline Protection (ME-09)

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The management levee between the GIWW and the
Cameron Prairie National Wildlife Refuge was in danger
of breaching as a result of erosion from boat traffic in the
GIWW. If breaching had occurred, wave energy from the
GIWW and salt water would have entered the organic,
freshwater wetlands.

A 13,200-foot rock breakwater was constructed 50 feet
from the northern bank of the GIWW to prevent waves
caused by boat traffic from overtopping and eroding the
remaining spoil bank.
The project’s effectiveness is being evaluated by shoreline
movement surveys and by comparing pre-construction and
post-construction aerial photographs for changes in marsh
loss rates.

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This project is located in Cameron Parish, Louisiana, on
the north shore of the Gulf Intracoastal Waterway
(GIWW), approximately 7 miles southeast of Sweet Lake
and to the east of Louisiana Highway 27 at its intersection
with the GIWW. It encompasses 640 acres of fresh marsh
and open water.

During 1993-97, while the project area had a 4.9% increase in
water coverage due to management for waterfowl, the
reference area remained unchanged.

The results of shoreline monitoring indicate that the project
has protected 13,200 feet of shoreline, along with 247 acres of
marsh north of the dike. This protection is expected to accrue
throughout the life of the project for a net restoration of at
least 23 acres. Monitoring has shown that the GIWW’s
northern shoreline advanced 9.8 feet per year in the project
area while retreating at a rate of 3.0 feet per year in the
reference area, indicating that low sediment availability does
not prohibit wetland creation behind rock dikes on navigation
channels.

To date, the project has exhibited success. It is expected that
the project area will continue to accrete new wetland area
between the spoil bank and the rock dike, further
safeguarding the adjacent wetland area from encroachment by
the GIWW.

This project is on Priority Project List 1.

 

The Federal Sponsor is USFWS

The Local Sponsor is CPRA

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Little Vermilion Bay Sediment Trapping (TV-12)

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High winds and waves prevent GIWW sediments transported down the Freshwater and Schooner bayous from settling and forming the basis of vegetated marsh. This same wind and wave energy also increases shoreline erosion rates.

This project involved the construction of a series of vegetated terraces to diminish waves in Little Vermilion Bay, helping to increase sediment deposition and reduce the rate of shoreline erosion. A pattern of channels was dredged 100-feet wide and 6-feet deep to beneficially distribute sediment from the GIWW through the Freshwater and Schooner bayous. Dredged sediments were used to construct 23 earthen terraces with a combined length of 23,300 feet. After settling, the average height of the terraces was 3.5 feet above mean sea level.

The bases of the terraces were planted with 20,450 containers of smooth cordgrass (Spartina alterniflora).

The design allows commercial and recreational fisherman to access the project area, and it stimulates fishery production by creating new habitat and increasing shoreline length.

In 1998 alone (prior to the project’s completion) 40 acres of wetland habitat were created.

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This project is located in the northwestern corner of Little Vermilion Bay at its intersection with the Gulf Intracoastal Waterway (GIWW) in Vermilion Parish, Louisiana. The project area encompasses 964 acres.

Monitoring is underway and preliminary observations show that the terraces are growing in width, and bay depth between terraces is decreasing indicating marsh expansion in the project area.

This project is on Priority Project List 5.

The Federal Sponsor is NOAA NMFS

The Local Sponsor is CPRA

Thankful for Wetlands

When celebrating Thanksgiving tomorrow, be sure to think about all of the ways wetlands provide for you and yours. Whether you enjoy the serene experience of watching a sunset through bald cypress trees, catching redfish in the marsh with your family, or simply love a good shrimp po-boy, Louisiana wetlands provide a huge number of services to millions of people daily.

In addition to protecting our cities from storm surge, wetlands of all kinds host tremendous species diversity, are highly productive, and allow for many types of recreation. Louisiana provides seafood nationwide. All of our most profitable species use wetlands for some part of their life cycle. [1] For example, shrimp spawn in estuaries, crawfish spend their whole semi-aquatic lives in freshwater wetlands, and oysters occupy coastlines while providing some wave attenuation and water filtration. CWPPRA and our partners see oysters as an alternative method to protect our some parts of our coast with artificial reefs that can also be harvested, making them a highly sustainable food source. Some foods we receive from wetlands aside from seafood include turtles and ducks in some cases, rice (a staple in many cultures worldwide), and a wide array of other plants for their tubers or berries.

Beyond the food, though, wetland benefits include flood protection to our major cultural hubs and carbon sequestration. Sequestering carbon makes wetlands wildly productive and an ally in the fight against global climate change. [2] CWPPRA was written into law in 1990 to help preserve these bountiful ecosystems so they can continue to thrive and benefit people in Louisiana and beyond. This holiday season, even if you are not eating any seafood during your feasts, you are benefitting from wetlands, so say a thank you for all of those natural areas that give us so much.

[1] https://www.epa.gov/sites/production/files/2016-02/documents/economicbenefits.pdf

[2] https://imedea.uib-csic.es/master/cambioglobal/Modulo_V_cod101611/Coastal%20sinks%20(seagrasses_mangroves_saltmarshes)/Bibliography_coastal/Chmura%20et%20al%202006.pdf

 

East Sabine Lake Hydrologic Restoration (CS-32)

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The lower salinity marshes are converting to shallow, open water due to elevated salinity events and subsidence. Navigation channels provide a direct route for salt water to infiltrate the marsh, disrupt the natural water circulation, and allow rapid runoff of fresh water. The larger Sabine-Neches Waterway and the Gulf Intracoastal Waterway (GIWW) have allowed saltwater intrusion into the project area’s fresh and intermediate marshes. Elevated tidal fluctuations in these channels have led to increased water flow, which has increased the conversion of marsh to open water. Area marsh loss is also caused by wave action along Sabine Lake and interior marsh shorelines and other natural causes (i.e., subsidence).

The project features include: a rock weir in Pines Ridge Bayou; three culverts with flap gates at Bridge Bayou; a 3,000 foot-long rock rip-rap breakwater along the Sabine Lake shoreline at Willow Bayou; a weir/plug at the opening at Starks South Canal Section 16 levee; and 232,000 linear feet of vegetated earthen terraces in the vicinity of Greens Lake.

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The project is located in the western portion of the Sabine National Wildlife Refuge from Pool 3 to the eastern shoreline of Sabine Lake in Cameron Parish, Louisiana.

Construction was completed in October 2010.

This project is on Priority Project List 10.

The Federal Sponsor is U.S. Fish and Wildlife Service

The Local Sponsor is CPRA

Coastal Permitting and Mitigation

With the United States midterm elections coming up, this week’s Wetland Wednesday focuses on the roles of government in coastal restoration, specifically permitting and mitigation. Of course, each coastal parish has their own government and representatives, and the State of Louisiana has dedicated offices for coastal restoration.

Anyone who wants to construct a restoration project in the coastal zone must go through the State of Louisiana Department of Natural Resources (DNR) to obtain the proper permitting, most commonly a Coastal Use Permit. [1] The DNR requires all who apply for a coastal use permit to prove that they have sufficiently addressed the need for environmental damage mitigation. CWPPRA-funded projects are permitted through this office because they have sufficient positive environmental impact. Our engineers and managers must prove that they have done the necessary surveys and sustainable development plans. Other coastal uses that require permitting include dock construction, dredging and infilling, and oil well capping and abandonment.

All permits are distributed with the intent of preserving net ecosystem integrity, meaning that if there is a large impact at the project location, damage mitigation measures are required. Recent legislation at the state level has been moving toward the idea of “Environmental Banking”, [2] which would allow developers to invest in the coastal zone, providing funds for restoration and earning credits that can be cashed in for mitigation needs. This process would get dollars on the ground in advance to help fund restoration. Since local damage is so common in development, environmental bank investors must invest in the bank that deals with the zone they will want to develop.

CWPPRA was enacted in 1990 to minimize coastal land loss. One of the most important goals of our projects is to provide a net benefit to the local environment. Legislation and permitting allow us to do this vital work, and we appreciate the efforts in Louisiana toward responsible coastal use. We hope everyone, both in government and the larger public, continues to view coastal land loss as a serious threat to the economy, ecosystems, and civilization.

[1] http://www.dnr.louisiana.gov/index.cfm?md=pagebuilder&tmp=home&pid=85&ngid=5

[2] http://www.jmbcompanies.com/Services/Mitigation/mitigation-banking-environmental

Girl Scouts B.I.G. Event

On September 29, CWPPRA Outreach visited with local Girl Scouts at their big event; the B.I.G. (Believe In G.I.R.L.) Event, hosted by Girl Scouts Louisiana East. Hundreds of scout groups walked the grounds of the University of New Orleans, bouncing from activity to activity. The aim of the event was to introduce girls to STEM, life skills, the outdoors, and other potential interests. Participants could learn about trade schools, non-Newtonian fluids (oobleck), and even get on a Coast Guard helicopter. Our table was constantly bustling despite being at the corner of the event. Our activity books, #ProtectOurCoast posters, and stickers were flying off the table. Our Wetland Jeopardy game was also a big hit, with teams playing cooperatively or with head-on competition between scouts. Nearby, the UNO Environmental Science department had a table set up to demonstrate how wetlands attenuate storm surge and form our first line of defense, the Master Naturalists of New Orleans brought some fascinating insects and a diamondback terrapin, and the Great Coastalini from CPRA (Chuck Perrodin) revealed the Louisiana coastline’s disappearing act.

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Classifying Wetlands Part 2

Last week’s Wetland Wednesday mentioned 3 main criteria as part of identifying a wetland (wetland hydrology, hydrophytic vegetation, and hydric soils). – Today we’ll look at how plants and soils help scientists delineate wetlands.

In the field, scientists identify and sample soils and plants as part of wetland delineation. The LSU AgCenter groups plant species based on where the plant is naturally found as seen in the table below.

indicator_2Wetland plants have adapted to flooded soils. “Obligate” plants can tolerate water at high levels or when soil saturation is a normal condition to that area. Examples of these plants include the bald cypress (Taxodium distichum), or cattail (Typha latifolia) [3].

In contrast, plants that cannot handle flooded conditions for an extended period would naturally be in the “upland” area of land (i.e. winged sumac (Rhus copallina), eastern redbud (Cercis canadensis), or panic grass (Dichanthelium sp.) [3].

People delineating wetlands focus on a project area according to aerial and soil maps along with aerial photographs [1]. Delineators then take soil samples and determine characteristics seen in hydric soils which relate to cycles of flooding and drying. – Examples of those include oxidized soils, hydrogen sulfide (rotten egg smell) and organic bodies found on plant roots. Finally, the plant and soil types are compared, tested, then matched to determine wetland boundaries for mapping and policy purposes [1].

Wetland delineation is a tool for protecting and documenting these important landscapes which contribute to a healthy and functional environment. It is important to note that wetland delineation requires much more than just plant and soil identification. CWPPRA utilizes sound science, engineering, mapping, and geo-technical surveys in the process of planning, approving, constructing, and maintaining coastal Louisiana wetland restoration projects.

Sources:

[1] Bedhun, Rebecca. 2018. “Watch and Lean Now: How To Do A Wetland Delineation”. Shoret Elliot Hendrickson Inc. Available: http://www.sehinc.com/news/watch-and-learn-now-how-do-wetland-delineation [September 9, 2018]

[2] Jon Kusler. “Common Questions: Wetland Definition, Delineation, and Mapping”. Association of State Wetland Managers, Inc. Available: https://www.aswm.org/pdf_lib/14_mapping_6_26_06.pdf [September 9, 2018]

[3] LSU Ag Center. 2018. Louisiana Plant Identification: Plant List. Available: http://www.rnr.lsu.edu/plantid/listcommon.htm [September 10, 2018]