Emergent marshes north of Terrebonne Bay have been
eroding as fast or faster than almost any other marshes
along coastal Louisiana. As these marshes convert to
shallow open water, the tidal prism will increase which will
in turn increase the frequency and duration of tides north
of Terrebonne Bay. This increasing tidal prism is likely
to increase the future interior marsh loss rates for those
marshes directly north of Terrebonne Bay. These marshes are
important for their habitat values as well as serving to slow
the progress of highly saline waters that threaten the lower
salinity marshes north and west of Madison Bay and in the
Lake Boudreaux basin. The
continued loss of these marshes has directly contributed to
the ongoing flooding problems of many communities along
Bayou Terrebonne including the town of Montegut.
The primary goal of this project is to fill shallow open water
areas and nourish marshes north of Terrebonne Bay/Lake
Barre thereby reducing the tidal prism north of Terrebonne
interior land loss from tidal scouring. Specific Goals: 1)
Create 365 acres of intertidal marsh in shallow open water
and nourish 299 acres of fragmented marsh within the
project area reducing
water exchange between Terrebonne Bay and interior lakes
during tidal and small storm events. 2) Reduce erosion along
16,000 ft of the northern Terrebonne Bay shoreline.
The proposed features of this project consist of filling
approximately 365 acres of shallow open water and
nourishing approximately 299 acres of very low or
fragmented marsh with material hydraulically dredged from
Terrebonne Bay/Lake Barre. Containment dikes will be
degraded/gapped within 3 years of construction to allow
for greater tidal and estuarine organism access. This project
could be one part of a phased comprehensive plan to protect
the northern shoreline of Terrebonne Bay and the interior
marshes from further erosion and reduce the tidal prism.
The project would result in approximately 353 net acres of
marsh over the 20-year project life.
This project is located in Region 3, Terrebonne Basin,
Terrebonne Parish, along the northern shoreline of Lake
Barre/Terrebonne Bay near Bayou Terrebonne continuing
east a short distance past Bayou Chitique.
This project is on Project Priority List (PPL) 20.
The Terrebonne Bay Marsh Creation-Nourishment project sponsors include:
- Federal sponsor: U.S. Fish and Wildlife Service
- Local sponsor: Coastal Protection and Restoration Authority