Humble Canal Hydrologic Restoration (ME-11)

wordpress fact sheet banner ME-11-01

The Grand and White Lakes system has been maintained
as a fresh-to-intermediate marsh environment. This has
been accomplished through water management using
natural ridges, levees, locks, and water control structures.
This project replaces the Humble Canal structure that has
fallen into disrepair. This project is compatible with the
overall basin strategy of treating critical areas of marsh
loss within the interior of the basin and managing water
levels with structures to relieve stress on interior wetlands.
The project also relieves this area from continued saltwater
intrusion from the Mermentau River that threatens the
viability of the fresh to intermediate marshes within the
region.

The objective of this project is to restore historical
hydrology to the project area by constructing a water
control structure consisting of five 48-inch diameter by 50-
foot long corrugated aluminum pipes with flap gates and
weir drop inlets along with one 18-inch diameter
corrugated aluminum pipe with screw gate. This structure
will protect the area from Mermentau River saltwater
intrusion and allow high water to drain from the marsh to
the river. Dredging of a small waterway is included to
increase the effectiveness of the structure.

map.jpg

The project is located in the Mermentau basin, on the west
bank of the Mermentau River approximately 2 miles
southwest of Grand Lake at the Humble Canal in Cameron
Parish, Louisiana.

Construction of the project was completed March 5, 2003.
The project is now in the operation and maintenance phase.

This project is on Priority Project List 8.

 

Federal Sponsor is NRCS

Local Sponsor is CPRA

Advertisements

Four Mile Canal Terracing and Sediment Trapping (TV-18)

wordpress fact sheet banner TV-18-01

The main cause of current marsh loss is a shoreline erosion
rate of approximately 8 feet/year. A combination of wind
and wake energy prevents sediments introduced by the Gulf
Intracoastal Waterway (GIWW) via the Vermilion River and
Four Mile Canal from allowing subaerial marsh development
in the area.

Reduction of shoreline erosion will be achieved by the
buffering capacity of the constructed terraces. The proposed
terrace layout is very different for each area of the project.
The “fish net” design for Little Vermilion Bay is designed to
allow sediment deposition and the terraces in Little White
Lake are aligned to reduce the wind generated waves, thus
reducing shoreline erosion. Thus, marsh habitat will be
created in two ways within the Four Mile Canal Terracing
Project area. First, marsh will immediately be built by
creating approximately 90 terraces from dredged material
and planting them with smooth cordgrass. This action alone
will create 70 acres of subaerial land. Second, by reducing
fetch and wave energy, terraces will promote the deposition
of suspended sediments in the shallow water adjacent to
the terrace edges in Little Vermilion Bay and Little White
Lake. This will slowly build marsh over the life of the
project as subaerial land is built and plants naturally become
established.

map.jpg

The project is located approximately 4 miles south of
intracoastal City in Vermilion Parish, Louisiana. The
project area includes all of Little White Lake and part of the
northeastern embayment of Little Vermilion Bay.

Project construction was completed in May 2004. No
maintenance activities have been undertaken as of 2017
and none are planned prior to project closeout. While some
terraces have eroded since construction, in general the
project is in good condition and functioning as intended.
Shoreline erosion has decreased and wetland acreage has
increased since construction.

This project is on Priority Project List 9

The Federal Sponsor is NOAA NMFS

The Local Sponsor is CPRA

Barataria Bay Waterway East Side Shoreline Protection (BA-26)

wordpress fact sheet banner BA-26-01

The banks of the Dupre Cut have eroded considerably as a
result of vessel wakes. Large breaches in the banks
exposed the adjacent marsh to increased water exchange,
tidal energy, and saltwater intrusion.

The objective of this project was to rebuild and stabilize
the east bank of the Dupre Cut. A stronger bank would
reduce erosion and help reestablish wetlands by allowing
sediment accretion on the leeward side of the foreshore
rock dike.

The project plan involved the construction of over 3 miles
of foreshore rock dike along the east bank of the Dupre
Cut to protect adjacent marshes from shoreline erosion.
This rock dike extends above the surface of the water and
will protect the fragile marsh area from boat wakes
generated within the BBWW.

map.jpg

The project is located in Jefferson Parish, Louisiana, on
the east bank of the Dupre Cut portion of the Barataria Bay
Waterway, north of the Lafitte Gas and Oil Field and south
of the subsided land reclamation effort known as “the
Pen.”

 

Construction was completed in June 2001. Baseline
monitoring information has been collected and will be
used to evaluate the project’s effectiveness. The O&M
Plan was signed in October 2002. This project is on
Priority Project List 6.

The Federal Sponsor is NRCS.

The Local Sponsor is CPRA.

Enhancement of Barrier Island Vegetation Demonstration (TE-53)

wordpress fact sheet banner TE-53-01Barrier Islands provide critical habitat and are the first line of defense to not only day-to-day coastal erosion but also to the destructive forces of major storm events. There remains a critical need to develop cost-effective improvements to existing restoration methodologies that will enhance the successful establishment and spread of vegetation in these important restoration projects. Developing methodologies to enhance vegetation establishment and growth in barrier island restoration projects is important in this very stressful environment because healthy vegetative cover traps, binds, and stabilizes sand and sediment, thereby improving island integrity during storm and overwash events.

The purpose of this demonstration project was to test several technologies and/or products to enhance the cost-effective establishment and growth of key barrier island and salt marsh vegetation. Humic acid and broadcast fertilization regimes were applied. The humic acid amendment and broadcast fertilization regime techniques are intended to “jump start” and facilitate the rapid establishment and expansion of vegetation. Humic acid benefits were demonstrated in both intertidal and supratidal plantings, whereas broadcast fertilization benefits were only demonstrated in supratidal plantings.

Each product (humic acid and fertilizer) is commercially available and off-the-shelf. Enhancing the establishment of woody vegetation (black mangrove and groundsel bush) was achieved via high-density dispersal techniques of propagules and seeds, a cost-saving alternative to planting container-grown transplants. All treatment test sections and reference planting areas were visually inspected and sampled quarterly (plant and soil variables) and compared to the reference area in order to develop recommendations for future planting projects.

This project involved greenhouse studies and the testing of technologies at two previously planted CWPPRA project sites. The CWPPRA projects involved were New Cut Dune and Marsh Restoration (TE-37) and Whiskey Island Back Barrier Marsh Creation (TE-50). Both sites are located in Terrebonne Parish in the Isles Dernieres Barrier Island area.

 

The project has been completed.

This project is on Priority Project List 16.

The Federal Sponsor is EPA

The Local Sponsor is CPRA

Dustpan Maintenance Dredging Operations for Marsh Creation in the Mississippi River Delta Demonstration (MR-10)

wordpress fact sheet banner MR-10-01

Hopper dredges must dispose of their material in deep
water, making the spoil material unavailable for direct
marsh creation, although the material may still provide
nourishment for the system. In comparison to hopper
dredges, spoil from dustpan and cutterhead dredges can be
disposed of in shallow, open waters for marsh creation.

The project demonstrated the safe operation of a dustpan
hydraulic dredge in the critical Head of Passes reach of the
Mississippi River. This demonstration enables the use of
this type of dredge for the maintenance of this reach and
additional opportunity for the beneficial use of the dredge
material. Over the course of this demonstration project,
approximately 40 acres of deteriorated marsh that had
converted to shallow open water was restored with
approximately 222,000 cubic yards of dredge material
over the course of 8 days or 192 operating hours with the
expectation of an increase in marsh.

map.jpg

The project is located in Plaquemines Parish, Louisiana, in
the Mississippi River Modern Delta. Dredging took place
near Cubit’s Gap, Head of Passes, and Southwest Pass.

The demonstration was completed in June 2002.
This project is on Priority Project List 6.

Lake Hermitage Marsh Creation (BA-42)

wordpress fact sheet banner BA-42-01

The project is within the West Pointe a la Hache Mapping Unit which lost 38 percent of its marsh from 1932 to 1990. By the year 2050, 28 percent of the 1990 marsh acreage is expected to be lost. That loss is expected to occur even with operation of the West Pointe a la Hache Siphon (State project BA-04). Significant marsh loss has occurred south and east of Lake Hermitage and along the eastern lake shoreline. Deterioration of the lake rim has exposed interior marshes to the wave energy of Lake Hermitage and increased tidal exchange. Based on USGS land-water data from 1985 and 2006, the project area has an annual loss rate of -1.64%.

The original project features included dredging in the Mississippi River and pumping sediments via pipeline to create 549 acres of marsh. Additionally, 6,300 feet of shoreline restoration using river material and 7,300 linear feet of terraces were included. Fortunately, a favorable bid on the construction contract allowed for project expansion and the marsh creation feature was increased to encompass a total of 795 acres.

Funding from the Louisiana Oil Spill Coordinator’s Office, the Louisiana Department of Natural Resources – Office of Coastal Management, and Deepwater Horizon Early Restoration allowed construction of an additional 215 acres of marsh. Terraces were removed from the CWPPRA project to provide an area for marsh creation with Deepwater Horizon Early Restoration funding.

map

The project area is located in the Barataria Basin, south and east of Lake Hermitage in Plaquemines Parish, Louisiana near the community of West Pointe a la Hache.

The Louisiana Coastal Wetlands Conservation and Restoration Task Force approved funding for engineering and design in February 2006 and approved construction funding in January 2009. Construction began in February 2012 and was completed in June 2015.

This project is on Priority Project List 15.

The Federal Sponsor is USFWS

The Local Sponsor CPRA

Penchant Basin Natural Resources Plan, Increment 1 (TE-34)

wordpress fact sheet banner TE-34-01

Area problems include major hydrologic alterations, interior marsh erosion, subsidence, saltwater intrusion, herbivory, and hurricane damage.

This project will combine the long-term realignment of Penchant Basin hydrology with restoration and protection measures aimed at maintaining the physical integrity of the area during the transition toward greater riverine influence.

The project includes about 6,520 feet of foreshore rock dike (shoreline protection) along the southern bank of Bayou Chene at its intersection with Bayou Penchant and approximately 35 acres of marsh creation. Two freshwater introduction structures, consisting of a) 10-48” flap gates in Superior Canal and b) steel sheetpile weir with 10’ boat bay and six 5’ x 5’ flap gated openings at Brady Canal, will be constructed to improve freshwater conveyance from Bayou Penchant into the central Terrebonne marshes. On the north bank of Bayou Decade extending from Lake Decade to Turtle Bayou (12,000 ft) an earthen embankment will be maintained and from Voss Canal to Lost Lake (14,000 ft) an earthen embankment will be constructed to 4.0 feet NAVD88 with 6:1 side slopes and rock armoring on the south-face. Within the embankment, a sheetpile weir, with a 10 ft wide boat bay, will be constructed at each of two existing channels that intersect Bayou Decade.

The objectives of the project are to eliminate erosion and create approximately 35 acres of emergent marsh along the southern bank of Bayou Chene at its intersection with Bayou Penchant, convey Atchafalaya River water, sediment, and nutrients to lower Penchant Basin tidal marshes to offset subsidence and saltwater intrusion and maintain the integrity of a deteriorated reach of the north bank of Bayou Decade to minimize encroachment of open water marine influence.

map.jpg

The project is bounded on the north by the Gulf Intracoastal Waterway (GIWW), the east by a north/south line from Lake De Cade to the GIWW, the south by Lake Mechant and Lost Lake, and to the west by a north/south line from Lost Lake to Avoca Island in Terrebonne Parish, Louisiana.

The Louisiana Coastal Wetlands Conservation and Restoration Task Force approved this project on April 24, 1997. Priority Project List (PPL) 6 authorized funding of $7,051,550, while PPL 8 authorized an additional $7,051,550.

Planning, engineering and design of this project included extensive data collection, hydrodynamic modeling, and related investigations. This effort resulted in a change in scope to the project which was approved by the Task Force in April 2008. Construction was completed in August 2011.

This project is on Priority Project List 6.

 

The Federal Sponsor is USDA NRCS

The Local Sponsor is CPRA