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Land
Change Maps
The
Louisiana coastal plain remains the largest expanse of coastal wetlands
in the contiguous United States. The coastal wetlands, built by
the deltaic processes of the Mississippi River, contain an extraordinary
diversity of estuarine habitats that range from narrow natural levee
and beach ridges to expanses of forested swamps and fresh, brackish,
and saline marshes. Taken as a whole, the unique interplay of habitats,
with their hydrological connections to each other, upland areas,
the Gulf of Mexico, and migratory routes of birds, fish, and other
species, combine to place the coastal wetlands of Louisiana among
the Nation’s most productive and important natural assets.
In human terms, these coastal wetlands have historically been a
culturally diverse center for social development.
The coastal wetlands
protect an internationally significant commercial-industrial complex
from the destructive forces of storm-driven waves and tides. This
complex includes deep-draft ports that handle the Nation’s
waterborne commerce and the most active segment of the Nation’s
Intracoastal Waterway. Louisiana’s coast is at the end of
the Central and Mississippi flyways, and nearly 70 percent of the
waterfowl migrating along these flyways winter on the Louisiana
coast. Coastal Louisiana also provides critical stopover habitat
for neotropical migratory songbirds, as well as other avian species.
Coastal Louisiana also provides critical nesting habitat for many
species of water birds such as the endangered brown pelican. These
economic and habitat values, which depend on the biological productivity
of Louisiana’s coastal wetlands, merit national attention.
Louisiana’s
coastal wetlands were built up by Mississippi River floodwaters
depositing enormous volumes of sediment and nutrients on the continental
shelf at its mouth. These sediments were eroded from the lands of
the vast Mississippi River basin in the interior of North America.
For the last several thousand years, the dominance of the land building
or deltaic processes resulted in a net increase of more than 4 million
acres of coastal wetlands. In addition, there was the creation of
an extensive skeleton of higher natural levee ridges along the past
and present Mississippi River channels, distributaries, and bayous
in the deltaic plain and beach ridges of the chenier deltaic plain.
The landscape this produced gave rise to one of the most productive
ecosystems on earth. Only the most intensively managed agricultural
systems that are artificially subsidized by large inputs of energy
and fertilizer could possibly rival the ability of these estuarine
wetlands to convert sunlight and carbon dioxide into biomass.
Today, most of the Mississippi
River’s freshwater with its nutrients and sediments are channeled
out to the deep waters of the Gulf of Mexico, bypassing the coastal
wetlands where they would otherwise naturally build land and nourish
the estuarine ecosystems. Deprived of the sediments provided by
the deltaic processes, the estuarine wetlands continue to sink,
or subside, as they have always done, but without the net land building
effect of the unconstrained natural deltaic processes. Deprived
of the natural sustenance provided by the nutrients available in
the intermittently flooded zone in which they are adapted to live,
the plants that define the surface of the coastal wetlands die off.
Once the coastal wetlands are denuded, the fragile substrate is
left exposed to - and unprotected from - the erosive tidal environment.
Coastal Louisiana has
lost over 900,000 acres since the 1930s. As recently as the 1970s,
the loss rate for Louisiana’s coastal wetlands was as high
as 25,600 acres per year. The current rate of loss is about 16,000
acres per year. It is estimated that coastal Louisiana will experience
a 320,000-acre net loss by the year 2050. The cumulative effect
of human activities in the coastal area has been to drastically
tilt the natural balance from the net land building deltaic processes
to land loss due to altered hydrology, subsidence, and erosion.
Approximately 30 percent of the land losses being experienced in
coastal Louisiana are due to natural causes. The remaining 70 percent
are attributable to man’s effect on the environment, both
direct and indirect.
In 1990, passage of the
Coastal Wetland Planning, Protection Restoration Act, (PL-101-646,
Title 111, CWPPRA), locally referred to as the Breaux Act provided
authorization and funding for a multi-agency task force to begin
actions to curtail wetland losses. In 1998, after extensive studies
and construction of a number of coastal restoration projects accomplished
under CWPPRA, the State of Louisiana and the Federal agencies charged
with restoring and protecting the remainder of Louisiana’s
valuable coastal wetlands adopted a new coastal restoration plan
in 1998. The underlying principles of the new plan, “Coast
2050: Toward a Sustainable Coastal Louisiana,” known as the
Coast 2050 Plan, are to restore and/or mimic the natural processes
that built and maintained coastal Louisiana. This necessitates basin-scale
action to restore more natural hydrology and sediment introduction
processes. The plan sub-divides Louisiana’s coastal zone into
four regions with a total of nine hydrologic basins. The plan proposes
ecosystem restoration strategies that would result in efforts larger
in scale than any that have been implemented in the past.
The Coast 2050
Plan report served as the basis for a Federal 905(b) Reconnaissance
Report for undertaking feasibility studies in 2000 to seek Water
Resources Development Act (WRDA) approval of a comprehensive plan
and authorization of major projects beyond what was being pursued
under CWPPRA. In 2000, it was envisioned that a series of feasibility
reports would be prepared over a 10-year period. The first feasibility
efforts focused on the Barataria basin and involved Marsh Creation
and Barrier Shoreline Restoration. However, early in fiscal year
(FY) 2002, it was recognized that a more in-depth comprehensive
study was needed that could be used early on to present to Congress
a Comprehensive Plan that could be submitted to Congress for a “Programmatic
Approval.” As a result, the Louisiana Coastal Area (LCA) Comprehensive
Coastwide Ecosystem Restoration Study was initiated. Subsequent
to authorization, detailed studies would be completed on features
of the Comprehensive Plan. As envisioned, these studies result in
project implementation reports (PIR). PIRs would be in detail, sufficient
to prepare plans and specifications to implement the proposed projects.
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