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
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