Order Code RS22276
September 15, 2005
CRS Report for Congress
Received through the CRS Web
Hurricane Katrina and the Coastal Louisiana
Ecosystem Restoration
Jeffrey Zinn
Specialist in Natural Resources Policy
Resources, Science, and Industry Division
Summary
Hurricane Katrina caused widespread damage and destruction to wetlands along
the central Gulf Coast. Prior to this hurricane, the U.S. Army Corps of Engineers had
been seeking approval from the 109th Congress for a $1.1 billion multi-year program to
construct five projects that would help to restore portions of the coastal Louisiana
ecosystem by slowing the rate of wetland loss and restoring some wetlands. This
funding would also be used to continue planning several other related projects. The
state of Louisiana and several federal agencies have participated in the development of
this program. This report introduces this program, discusses whether it might have
muted the impacts of a hurricane of the magnitude of Katrina and whether the
devastation caused by the hurricane might cause the Corps and other restoration
supporters to propose either altering aspects of this proposed program, or expanding it.
This report will be updated as more information becomes available about either the
storm’s effects on coastal Louisiana and its wetlands, or about any changes in the
proposed program in response to this natural disaster.
Introduction
The 109th Congress has been considering provisions in legislation (S. 728 and H.R.
2864) that would authorize the U.S. Army Corps of Engineers (Corps) to implement
numerous activities to slow the rate of coastal wetlands loss in Louisiana over the next
decade. Both bills would authorize funding to implement a program that the Corps
recommended in a November 2004 feasibility report. The Corps recommended $1.1
billion for activities to be initiated immediately, and estimated an additional cost of $0.9
billion for future work. Of the initial $1.1 billion, $828 million is to complete planning
and construct five projects, called “near-term features,” where the planning process is well
along, and construction could be completed in about a decade. The remainder of this
initial authorization would be spent on: monitoring program performance; building small
demonstration projects (a maximum cost of $25 million per project); exploring options
to use dredged materials to create wetlands; and continued planning of 10 additional
projects that would have to be authorized at a future date. Finally, additional funding
Congressional Research Service { The Library of Congress

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would be provided to study six less well defined possible program elements for the future,
termed “large-scale, long-term coastal restoration concepts.” The House version, passed
by the full House on July 25, 2005, authorizes a total of $1.218 billion, while the Senate
version, reported by the Senate Environment and Public Works Committee, does not
specify any dollar amounts, but authorizes the restoration program “substantially in
accordance with” the report from the Corps. (For more information on this plan, see CRS
Report RS22110, Coastal Louisiana Ecosystem Restoration: The Recommended Corps
Plan, and to follow the legislative process, see CRS Issue Brief IB10133, Water
Resources Development Act (WRDA): Army Corps of Engineers Authorization Issues in
the 109th Congress.)
Background
The Corps recommendations for investments to slow wetland losses in November
2004 is the most recent effort in a series of federal and state actions over the past four
decades, since a rapid rate of coastal wetlands loss was first documented in coastal
Louisiana. It is now believed that more than 1.2 million acres of wetlands, an area
approximately the size of Delaware, has been converted to open water since the 1930s.
The remaining wetlands cover an area of about 3.5 million acres, an area slightly large
than Connecticut. The U.S. Geological Survey has estimated that an additional 448,000
acres could be lost in coastal Louisiana by 2050 if no additional restoration projects are
initiated. If the Corps’ program is implemented, it estimates that net wetland losses
would be reduced to 170,000 acres by 2050.
These losses have been caused by a combination of human activities, such as
dredging to develop navigation channels and support of the development of the oil and
gas industry, and damming throughout the Mississippi River watershed that holds back
sediments that had been deposited in coastal Louisiana; and natural factors, such as higher
sea levels and a slow compaction of sediment around the Mississippi River delta.
Proposals to respond to these losses have centered on rebuilding the region’s coastal
wetlands in ways that could reduce the ecological, economic, and social costs. These
proposals are somewhat independent of each other because of the large expanse of coastal
Louisiana. This independence is in contrast to most other large-scale ecosystem
construction and restoration programs, such as the south Florida Everglades restoration,
where component projects are interrelated, and success depends on completing the overall
program. One cost that results from these several decades of wetland losses is the
diminished role that they can play in reducing the impact of hurricanes by absorbing storm
surges and thereby decreasing flood elevations and wave energy.
The Corps’ recommended program includes projects centered in the wetlands south
and southwest of New Orleans. In its analysis of the selected set of options and
alternative proposals included in the November 2004 final report, there is almost no
mention of hurricanes or an analysis which compares how these proposals might mitigate
the effects of a major hurricane. In making these recommendations in the final report, the
District Engineer for New Orleans states, in the general introduction to the
recommendations, that “I am convinced that the LCA [Louisiana Coastal Area] Plan
would begin to reverse the current trend of degradation of Louisiana’s coastal ecosystem,
support Nationally significant living resources, provide a sustainable and diverse array of
fish and wildlife habitats, reduce nitrogen delivery to offshore gulf waters, provide

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infrastructure protection, and make progress towards a more sustainable ecosystem.”1
This focus on the ecological improvements of rebuilding wetlands, and the social and
economic benefits that accompany these improvements, does not incorporate the likely
benefits associated with a reduction of storm damage by stabilizing coastal barriers,
accumulating sediment that would lead to reestablishing wetland vegetation, and the like.
When Hurricane Katrina struck, Congress had not yet authorized any restoration
program. However, two prototype projects, the wetland restorations at Davis Pond and
Caernarvon Diversions, had been initiated under other authorities. Both diversions are
located in the greater New Orleans area along the main channel of the Mississippi River.
Fresh water from this river bearing sediment is periodically introduced into the diversion
sites, which are large rectangular areas bounded by low levees. As the water sinks below
the surface or evaporates, it leave sediments and raises land elevation, which, in turn,
provides an environment in which wetland habitat can be established. These diversions
are planned to add about 50,000 acres of wetlands over 50 years. As of mid-September,
there has been no information about how these two diversion sites fared as a result of
Hurricane Katrina. As more information on these effects become available, it may help
the Corps determine how future diversion projects might be designed, taking into account
the potential effects of major storm events, and what effect the presence of these
diversions have on surrounding areas in major storm events.
Katrina’s Effect on Restoration Planning: Back to the Future
In the wake of Hurricane Katrina, some supporters of restoration are calling for a
more substantial program than the Corps is currently proposing and Congress is
considering. They are calling for reconsideration of a $14 billion restoration effort, as laid
out in the Coast 2050 Plan, which was released in 1998. This planning effort, which was
led by the Corps and involved numerous federal and state agencies, resulted in 77
“restoration strategies” recommendations, to be completed over a 50-year time period.
Many of these strategies are construction projects. The strategies would be distributed
along the entire length of the Louisiana’s coastal area. The anticipated result of these
strategies, if fully implemented, was to protect or restore almost 450,000 acres of
wetlands.
To date, Congress has not considered legislation authorizing the Coast 2050 Plan.
Instead, in 2000, the Corps and the state began to develop a more modest set of proposals
for projects that could be implemented over a 10-year time period. A draft was
completed in October 2003, but never officially released. It included several options for
implementation with estimated costs that reportedly ranged between $4.3 billion and
$14.7 billion. However, the Administration, represented by the Office of Management
and Budget, reviewed these recommendations and cost estimates, then reportedly directed
the Corps to come up with a less costly proposal; that is the proposal which Congress is
currently considering.
1 U.S. Army Corps of Engineers. Louisiana Coastal Area (LCA) Ecosystem Restoration Study.
Final Report. New Orleans, November, 2004. p. MR 6-1.

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Effects of Katrina on Louisiana’s Coastal Wetlands and Barrier
Islands
Documenting the effect of Hurricane Katrina on coastal Louisiana will be a long
process that is just starting. Coastal Louisiana is an extremely flat and dynamic physical
environment where major storm events can greatly alter the surface features, especially
wetlands, beaches and barrier islands. Some “before and after” photographs, such as
those on the U.S. Geological Survey’s website [http://www.nwrc.usgs.gov/hurricane/post-
hurricane-katrina-photos.htm] indicate that wetlands (and coastal barriers and beaches)
have been replaced by open water over large areas. An initial estimate by scientists that
has been widely reported in the press is that the storm converted to open water more than
30 square miles of a 133-square-mile area of marsh in the Breton Sound. This Sound lies
to the east of New Orleans and near the area of greatest hurricane impact.
However, some portion of those losses may only be temporary, as wetland vegetation
was flattened by storm surge and strong wind, and coastal beach sand and sediment were
redistributed by these same forces. In addition, in some locations where the storm
deposited sediment, wetlands may emerge. The focus in the media has been, first and
foremost, on the flooding in New Orleans and, then on the center of hurricane damage in
coastal Mississippi, with much less attention to the small towns and sparsely populated
areas east and south of New Orleans, and along Louisiana’s coast. More information on
coastal Louisiana should start to become available as scientists can access the area and
survey the physical changes.
The wetlands were protected from ocean storms in many areas by a thin ribbon of
coastal sand barriers and beaches along the shoreline. These barriers provide what is
sometimes characterized as a speed bump which creates friction that helps to break up and
slow down storm surge. It also provides a barrier to salt water, protecting wetland plants
and ecology by keeping the water on the landward side of the barriers and beaches less
saline than sea water.
The coastal barrier system in Louisiana has also been deteriorating for many of the
same reasons as the wetlands, both human and natural. Stabilization and restoration of
some of these barriers was recognized as critical to any successful effort to protect the
wetlands behind these barriers. Hurricane damage to these barriers may greatly affect the
overall restoration effort. Landward of where they were overtopped, flattened, or bisected
by new inlets, it may be particularly challenging to reestablish wetlands because of the
presence of hurricane-related changes to this landscape. Over time, some of these barriers
may stabilize and rebuild in new locations, but these changes will not be clear for some
time. Initial observations that has been reported in the press from a flyover of the
Chandeleur Islands, a chain of barrier beaches and islands about 70 miles east of New
Orleans, is that they were heavily damaged, but it is not known whether these changes
will be permanent, or whether these islands will start to recover in calmer conditions.
What If the Restoration Program Had Been Completed Before
Katrina?
Damage generally is most extensive along the east side of a hurricane storm track in
the Gulf of Mexico, where the wind blows from south to north and the storm surge is

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most pronounced. In the case of Katrina, the storm track was just east of New Orleans,
and the highest storm surge was documented to the east of that track. By contrast, within
100 miles of New Orleans west and northwest, such as in the nearby Baton Rouge area,
the damage is far less severe and extensive. If the entire first phase of the restoration
program had been completed, that is, if Congress had authorized and the Corps had spent
the entire $1.1 billion, as recommended in the November 2004 Corps report, for a
combination of construction and further investigations, it may be that these investments
would have had little effect on the pattern or extent of flooding or other storm damage
around the city of New Orleans, and only a limited effect on damage elsewhere. The
stability of the levees and floodwalls around the city would not have been enhanced by
any component of the restoration program, so this investment would not have affected a
floodwall breeching or flooding in the city. Where the most severe damage occurred to
the east of the city, the restoration program would have had little activity, at least in the
initial phase. Perhaps these relationships between this hurricane event and the proposed
restoration (and the two existing prototype diversions) should be examined to help inform
any debate over future priorities for a restoration program.
The potential damage from any storm event, and the role the restoration would play
in muting those damages, depends on specific characteristics of the storm event, including
such factors as the storm’s intensity, its precise track, the speed at which it is moving, and
the tidal elevation at land fall. Scientists have pointed out that coastal wetlands cause
friction to storm surge; one estimate is for every 2.7 miles of marsh this surge passes over,
its elevation is reduced by a foot. Estimates from other scientists expressing a similar
relationship is that storm surge is reduced by a foot in adjacent inland areas for every
square mile (640 acres) of wetlands that are restored. A possible conclusion is that the
restoration could have a great beneficial effect mitigating the damage to coastal Louisiana
from storm events with some characteristics and especially near the coast. However, for
hurricanes with many combinations of characteristics, this set of projects may have little
or no effect on reducing the impacts from the storm.
Possible Effect of Hurricane Katrina on Restoration Efforts
Katrina may have had some adverse effects on the two diversions that have already
been initiated to restore wetlands at Caernarvon and Davis Pond. However, no such
effects have been reported as yet. How these restoration sites stood up to the forces of the
hurricane could provide considerable insights into the diversion approach, and this
information will be very helpful in planning future wetland restorations.
All the major restoration planning has been in response to wetland losses and coastal
degradation within the Louisiana state boundaries. However, the physical processes at
work and the track of Hurricane Katrina did not respect these boundaries, and caused
extensive damage in coastal Mississippi and Alabama. The impact of this storm may
cause Congress not only to consider how to move ahead with a restoration program for
Louisiana, but also whether such an effort can be more effective if it includes components
that would provide the same damage-mitigating benefits in coastal Mississippi and
Alabama.
Even if Congress authorizes either the pending legislative proposal or some larger
amount for restoration, physical changes on the ground will not be in place for decades.
The five projects where authorization is currently pending are not anticipated to be

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completed for about a decade. Most of the other construction projects are much earlier
in the planning process, and therefore completion will be further into the future. The time
required for planning and engineering work that precedes actual construction can be
completed could also be extended if the engineering resources of the Corps have to also
address the many other project needs, such as levee enhancement, generated by Katrina.
Under the best of circumstances, the array of projects in a complex and comprehensive
program like Coast 2050 could not be completed for decades.
Another consideration will be how policy and program responses to the flooding in
New Orleans will be viewed in relation to the restoration effort. As stated earlier, little
that is proposed in the current legislation would have had much effect on alleviating the
causes behind the levee failures or moderating the rate or pattern at which the city was
subsequently flooded. It does not appear that the many additional projects that were in
the 1998 Coast 2050 Plan would have a significant mitigating effect on the flooding
associated with this specific natural disaster. If Congress makes the protection or
“fortification” of New Orleans through levee improvements and other possible projects
such as flood barriers its highest priority, then some financial and agency resources may
be drawn away from other projects, such as those in the restoration efforts, that contribute
only indirectly to protecting the city. This could reduce the scale of threat and damage
to communities to the South. If Congress wishes to address both needs at the same time,
then it may also want to consider setting priorities among the protection activities that it
authorizes. At a minimum, Congress might consider asking the Corps to examine how
each of these projects might mute future storm damage, and whether there are some
modifications that could be made to these projects that would increase benefits of
protecting the city or other south Louisiana communities.

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