Order Code RS22276
Updated November 18, 2005
CRS Report for Congress
Received through the CRS Web
Hurricanes Katrina and Rita and the Coastal
Louisiana Ecosystem Restoration
Jeffrey Zinn
Specialist in Natural Resources Policy
Resources, Science, and Industry Division
Summary
Hurricanes Katrina and Rita caused widespread damage and destruction along the
central Gulf Coast. Prior to these hurricanes, the U.S. Army Corps of Engineers had
been seeking approval from the 109th Congress for a $1.1 billion multi-year program to
both construct five projects that would help to restore portions of the coastal wetland
ecosystem in Louisiana and 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, and discusses whether it might have
muted the impacts of hurricanes of the magnitude and paths of Katrina or Rita and
whether the devastation caused by both hurricanes might cause the Corps to consider
different restoration options. The National Research Council issued a report in
November 2005 that may help inform the current debate over restoration. This report
will be updated.
Introduction
The widespread destruction has altered the congressional perspective as it considers
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 would be provided to study six
less well defined possible program elements for the future, termed “large-scale, long-term
Congressional Research Service ˜ The Library of Congress

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coastal restoration concepts.” H.R. 2864 was approved by the House on July 25, 2005,
while S. 728 was reported by the Senate Environment and Public Works Committee on
April 26, 2005. (For more information on the proposed Corps program, see CRS Report
RS22110, Coastal Louisiana Ecosystem Restoration: The Recommended Corps Plan, by
Jeffrey Zinn; and to track the legislative process, see CRS Issue Brief IB10133, Water
Resources Development Act (WRDA): Army Corps of Engineers Authorization Issues in
the 109th Congress
, by Nicole T. Carter, coordinator.)
The National Research Council was asked to review this plan, addressing specific
questions about: (1) the scientific underpinnings of the Corps study; (2) major questions
that need to be answered to support implementation; (3) the national benefits of the
restoration; and (4) the plan as a first step toward comprehensive coastal restoration. In
its prepublication report, issued in November 2005, it comments on the projects that are
proposed and on the effects of the hurricanes on these plans. It concludes that while the
individual projects are sound, they do not provide a comprehensive approach to
addressing loss of wetlands over such a large area. It calls for the development of a
detailed map showing the desired landscape of coastal Louisiana that would serve as the
basis for future actions. The full report, titled Drawing Louisiana’s New Map:
Addressing Land Loss in Coastal Louisiana
can be downloaded at
[http://www.nap.edu/catalog/11476.html].
Background
The Corps recommendations for projects to restore some wetlands and slow wetland
losses in November 2004 is the most recent of numerous sets of proposals offered over
the past four decades since a rapid rate of coastal wetlands loss was first documented. It
is now estimated 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 about 3.5 million acres, an area slightly large than Connecticut. The U.S.
Geological Survey 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 estimates do not appear to account for major hurricane events.
These losses have been caused by a combination of human activities and natural
factors that have been frequently documented in many studies by the Corps and others.
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. One cost
receiving far more attention in the wake of the hurricanes is the diminished role that the
remaining wetlands can play in reducing the impact of hurricanes by absorbing storm
surges and thereby decreasing flood elevations and wave energy. However, given the
large expanse of coastal Louisiana, it seems most likely that each project would have
benefits on the site and perhaps in the immediate surrounding area. This lack of
interconnection among projects that make up the program is in contrast to the Corps’
other large-scale ecosystem construction and restoration programs around the country,
such as the south Florida Everglades restoration, where component projects are
interrelated, and success depends on completing all the pieces in the program.
The Corps’ recommended program includes projects centered in the wetlands south
and southwest of New Orleans. None of these projects are in the western portion of the

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Louisiana coast where Rita struck, and few are east of New Orleans, where Katrina’s
damage was most concentrated. In its analysis of the selected set of options and the many
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
infrastructure protection, and make progress towards a more sustainable ecosystem.”1
While Congress has not yet authorized any restoration program, two prototype
projects, the wetland restorations at Davis Pond and Caernarvon Diversions, had been
initiated under other authorities. Both restorations 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 receptacle
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 reestablished. These two diversions are planned to add about
50,000 acres of wetlands over 50 years.

Effects of Katrina and Rita on Restoration Planning
In the wake of the hurricanes, some supporters of restoration are calling for a more
substantial (and expensive) program than the current proposal before Congress. They are
seeking consideration 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 50 years. The strategies would be distributed
along the entire length of the Louisiana’s coastal area, but concentrated in the central
coast. 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 and Rita on Louisiana’s Coastal Wetlands and
Barrier Islands

Documenting the full effect of the hurricanes on coastal Louisiana will be a long
process. 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 showing the damage caused by
Hurricane Katrina, 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. By contrast, Hurricane Rita made landfall where coastal landforms are dominated
by cheniers, which are slightly elevated ridges that parallel to the coast and are vegetated
by shrubs and trees. Cheniers block the flow of salt water from the ocean and have lead
to extensive fresh water basins on the landward side, and brackish water and salt water
marshes on the ocean side. The U.S. Geological Survey estimates that about 65,000 acres
of wetlands were converted to open water by the two hurricanes, with far greater loss
resulting from Katrina and concentrated south and east of New Orleans, according to a
November 1, 2005 press release.
Some portion of the losses caused by both storms may only be temporary, as wetland
vegetation was flattened by storm surge and strong wind, and coastal beach sand and
sediment was redistributed by these same forces. In addition, in some locations where the
storm deposited sediment, wetlands may emerge. More information on wetland losses
should start to become available as scientists can access both storm areas and survey the
physical changes.
The wetlands were protected from ocean storms in central and eastern portions of
coastal Louisiana 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. They also provide a
barrier preventing salt water in the Gulf from reaching freshwater wetland plants and
disrupting the ecology of this wetlands-based ecosystem.
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. It may be particularly challenging to reestablish wetlands
landward of where they were overtopped, flattened, or bisected by new inlets because of
the influx of salt water. Over time, some of these barriers may stabilize or rebuild in new
locations, but these changes will not be clear for some time. Initial observations show
heavy damage, but it is only slowly becoming clearer which changes will be permanent,
and which islands will start to recover in calmer conditions.
What If the Restoration Program Had Been Completed Before the
Hurricanes?

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, with the greatest
damage near the Louisiana-Mississippi state line. By contrast, within 100 miles of New
Orleans west and northwest, such as in the nearby Baton Rouge area, the damage is far
less extensive. The same general configuration of damage occurred with Hurricane Rita,
with the worst damage in western Louisiana, just to the east of the storm’s track.
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 that 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, with the
possible exception of modifications to the Mississippi River Gulf Outlet (MRGO). These
projects likely would have had some mitigating effects in the immediate areas around the
projects, but little effect further away. The stability of the levees and floodwalls around
the city would not have been directly 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 from Hurricane
Katrina and in the western portion of the state from Hurricane Rita, the restoration
program would have had little activity. Perhaps these relationships between the two
hurricanes 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. Some scientists have offered support for the restoration
effort by pointing out that coastal wetlands cause friction to dampen storm surge, and
estimate that for every 2.7 miles of marsh this surge passes over, its elevation is reduced
by a foot. They also estimate that storm surge is reduced by a foot in adjacent inland areas
for every square mile (640 acres) of wetlands that are restored. Other scientists caution
that these general relationships can vary widely, based on site specific and storm
characteristics. A possible conclusion is that some restoration projects 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 specific set of projects may have limited or no
positive effect on reducing the storm’s impacts in much of the greater New Orleans area.
Possible Effect of Hurricane Katrina and Hurricane Rita 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 post-
hurricane damage assessments have been issued; such assessments may help the Corps
in designing future diversion projects.
The hurricanes may greatly expand the range of thinking about restoration options.
One aspect of that expansion is that while all past restoration planning has been in
response to wetland losses and coastal degradation within the Louisiana state boundaries,

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neither hurricane respected those boundaries, and caused extensive damage in coastal
Mississippi and Alabama, and less extensive damage in Texas. The pattern of impact of
these storms may cause lead to greater interest in considering that a restoration program
can be more effective if it includes components that would provide damage-mitigating
benefits in coastal areas of adjoining states. A second aspect is projects that would result
in larger changes. The National Research Council report, for example, discusses both the
third delta and the abandonment of the current delta in the context of providing more
sediment for restoration.
Even if Congress authorizes either the pending legislative proposal or some larger
amount for restoration, many of the physical changes on the ground will not be in place
for decades. Construction of the five projects for which authorization is currently pending
are not anticipated to be completed for about a decade. For diversion projects,
construction is but the first step, and actual reestablishment of wetlands require many
additional years. 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 New Orleans levee enhancements and navigation features,
generated by Katrina. Under the best of circumstances, the array of projects in a complex
program like Coast 2050 could not be completed for decades.
In the aftermath of the hurricanes, the ecosystem restoration goals will be in
competition with other goals in coastal Louisiana for federal resources. Two of these
goals are hurricane protection including mitigation, and economic development generally
associated with navigation. While these three goals have some, and perhaps considerable,
overlap, it may be too expensive to fully support all of them at the same time. For
example, how will policy and program responses to the flooding in New Orleans 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 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 its highest
priority, then some financial and agency resources may be drawn away from other
projects, such as those in the restoration efforts, that would contribute only indirectly to
protecting the city. But such a decision could reduce the restoration efforts that would
reduce the magnitude of threat to communities and resources south of the city and closer
to the Gulf. If Congress wishes to address both goals 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 the
restoration projects might mute future storm damage, and whether there are some
modifications that could be made to pending projects that would further protect the city
or other south Louisiana communities.