Coastal Louisiana Ecosystem Restoration After Hurricanes Katrina and Rita

Coastal Louisiana Ecosystem Restoration
After Hurricanes Katrina and Rita
Jeffrey A. Zinn
Specialist in Natural Resources Policy
Resources, Science, and Industry Division
Summary
Prior to Hurricanes Katrina and Rita, the U.S. Army Corps of Engineers had been
seeking congressional approval for a $1.1 billion program both to construct five projects
that would help restore specified sites in the coastal wetland ecosystem in Louisiana, and
to continue planning several other related projects. The state of Louisiana and several
federal agencies participated in the development of this program. This report introduces
the program and more extensive restoration options that are being discussed in the wake
of the hurricanes. It also discusses whether this program, if completed, might have
muted the impacts of the hurricanes. Congressional consideration are being informed
by new information about the extent of coastal wetland change that resulted from the
hurricanes and further changes since the hurricanes struck. This report will be updated.
Introduction
The widespread destruction caused by Hurricanes Katrina and Rita altered the 109^th
Congress’s perspective on coastal Louisiana restoration as it considered provisions in
legislation (e.g., S. 728 and H.R. 2864) that would have authorized the U.S. Army Corps
of Engineers (Corps) to implement activities to slow the rate of coastal wetlands loss.
Both bills, developed before the hurricanes struck, would have authorized funding to
implement a program that the Corps had recommended in a November 2004 feasibility
report, including $1.1 billion for activities to be initiated immediately, and $0.9 billion
for future work. Since the hurricanes, more expansive options, costing up to $14 billion
and requiring up to three decades before they are fully implemented, are also being
considered. As no restoration legislation was enacted in the 109^th Congress, the 110^th
Congress is again addressing this issue in Water Resources Development Act (WRDA)
legislation that has passed both chambers (H.R. 1495) and was sent to the White House
on October 23, 2007. The Administration has indicated that it intends to veto the bill.
Of the initial $1.1 billion in the proposal Congress was considering when the
hurricanes struck, $828 million was to complete planning and construct five projects,
called “near-term features.” The remainder of this initial authorization would have been

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 had to
be authorized at a future date. Finally, additional funding would have been provided to
study six less defined possible program elements for the future, termed “large-scale, long-
term coastal restoration concepts.” H.R. 2864 had been approved by the House on July
25, 2005, while S. 728 had been reported by the Senate Environment and Public Works
Committee on April 26, 2005.
After the hurricanes struck, Congress provided $96 million in FY2006 Defense
appropriations (P.L. 106-148) for activities to reduce threats to New Orleans by
improving coastal wetlands, leaving open the potential for a wide range of legislative
actions in the future. The projects and most other major elements of these proposals can
be found in the current version of H.R. 1495, which has been sent to the White House.
(For more information on the proposed Corps program, see CRS Report RS22110,
Coastal Louisiana Ecosystem Restoration: The Recommended Corps Plan, by Jeffrey
Zinn; for information on authorizing legislation, see CRS Report RL33504, Water
Resources Development Act (WRDA): Army Corps of Engineers Authorization Issues,
coordinated by Nicole T. Carter.)
The National Research Council was asked to review the Corps’ recommended plan.
It recognized that these hurricanes, which struck after the report was largely completed,
will likely lead to reconsideration of some plan components. It concluded that while most
of the individual projects are sound, they are not a comprehensive response to wetlands
loss. It calls for the development of a detailed map showing the desired landscape of
coastal Louisiana that would serve as the basis for selecting future actions. The lack of
synergy among projects in this plan contrasts with another Corps large-scale ecosystem
construction and restoration program in the south Florida Everglades, where success
depends on completing all the interrelated program components.¹
Background
The Corps recommendations for projects to restore some wetlands and slow wetland
losses in November 2004 is the most recent of many such proposals offered over the past
four decades, shortly after the 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 larger than Connecticut. The U.S.
Geological Survey estimated, before the hurricanes, that an additional 448,000 acres could
be lost by 2050 if no additional restoration projects are initiated. If the Corps’ program
is implemented, it estimated that net wetland losses would be reduced to 170,000 acres
by 2050. These estimates do not appear to account for major but unpredictable hurricane
events.
These losses have been caused by a combination of human activities and natural
factors that have been documented in many reports by the Corps and others. Proposals

¹ The full report, titled Drawing Louisiana’s New Map: Addressing Land Loss in Coastal
Louisiana, can be downloaded at [http://www.fermat.nap.edu/catalog/11476.html].

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 today is the role that wetlands can play in absorbing storm surges and
thereby decreasing flood elevations and muting the force of wave energy.
The Corps’ current recommended program includes projects centered in the wetlands
south and southwest of New Orleans. No projects are in the western portion of state
where Rita struck, and few are east of New Orleans, where Katrina’s damage to coastal
development and the environment was most concentrated. In the Corps analysis of the
selected set of options and the alternative proposals included in the November 2004 final
report, there is almost no mention of hurricanes, nor an analysis comparing how these
proposals might mitigate the effects of a major hurricane. The District Engineer for New
Orleans did not mention hurricanes when he made his recommendations, stating: “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.”²
While Congress has not yet authorized any restoration program, two prototype
restoration projects — Davis Pond and Caernarvon Diversions (opened in 2005 and 1991,
respectively) — had been initiated under existing authorities. The primary purpose of
both diversions is to introduce fresh water (bearing sediment) into the wetland areas, and
thereby reduce the salinity. Both restorations are located in the greater New Orleans area
along the main channel of the Mississippi River. River water is periodically introduced
into these sites, which are large receptacle areas bounded by low levees. As the water
sinks into the ground or evaporates, it leaves 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 Recent Hurricanes on Restoration Planning
In the wake of the 2005 hurricane season, some supporters of restoration, especially
from within the state, are calling for a more substantial program than in the current
legislation. Supporters emphasize that the hurricanes caused nationally significant
disruptions, especially to energy supplies and bulk transportation, and therefore the
restoration would have significant national benefits. They are seeking consideration of
a $14 billion restoration effort that had been laid out in the Coast 2050 Plan, released in
1998. This Corps-led planning effort resulted in recommendations for 77 “restoration
strategies” 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 south
and southwest of New Orleans. The anticipated result from fully implementing these
strategies would be to protect or restore almost 450,000 acres of wetlands.
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

² U.S. Army Corps of Engineers, Louisiana Coastal Area (LCA) Ecosystem Restoration Study,
Final Report, New Orleans, November 2004, p. MR 6-1.

projects that could be initiated over a 10-year time period. A draft, completed in October
2003 included several options with estimated costs that ranged between $4.3 billion and
$14.7 billion. However, the Administration’s Office of Management and Budget directed
the Corps to come up with a less costly package of proposals in late 2003; that package
is what Congress was considering when the hurricanes struck.
Effects of Recent Hurricanes on Coastal Louisiana
Documenting the full effect of the 2005 hurricane season 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 portion of the losses caused by both storms
were only 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 and beaches may emerge
or expand. A U.S. Geological Survey summary of wetland changes, released in October
2006, estimates that almost 140,000 acres of wetlands were converted to open water
throughout the state’s coastal areas. Losses were most extensive in Breton Sound,
southeast of New Orleans. This summary also points out that this loss is about 42% of
the total losses previously predicted to take place between 2000 and 2050 (periodic storms
were included in making the calculation).
The wetlands were partially 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 barrier systems were heavily damaged. These barrier systems
already had been deteriorating for many of the same reasons, human and natural, as the
wetlands. Stabilization and restoration of them is critical to successfully restoring the
wetlands that they protect. It may be particularly challenging to reestablish wetlands
landward of where barriers were overtopped, flattened, or bisected by new inlets that
allow an influx of salt water. Over time, some of these barriers may stabilize or rebuild
in new locations; others will require extensive restoration.
What If the Restoration Program Had Been Completed
Before the Hurricanes Made Landfall?
If the entire first phase of the restoration program had been completed, that is, if
Congress had authorized and the Corps had completed the five initial projects
recommended in the November 2004 Corps report, 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 on flood elevations and water flow velocities close to the projects sites, but the
magnitude of the effect would decline quickly as one moved 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 none of these projects would have reduced the
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. Relationships between the hurricane
impacts on New Orleans and coastal communities and the proposed restoration may help

decision makers identify future restoration priorities, if they choose to follow the
recommendations in the 2005 NRC report.
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 (e.g., the
storm’s intensity, track, and speed of moving), the components of the restoration effort,
and the status of each component. 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 most pronounced. In the case of Katrina, the storm track was
just east of New Orleans, and the highest storm surge and greatest damage was
documented to the east of that track. By contrast, within 100 miles of New Orleans west
and northwest — for example, in the nearby Baton Rouge area — the damage was far less
extensive.
Some scientists have offered generic 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 mask a wide variability, based on site-specific and storm characteristics. A
possible conclusion is that some restoration projects could have a great beneficial effect
in mitigating the damage to coastal Louisiana from storm events with certain
characteristics, and these benefits would be greatest near the projects. However, for
hurricanes with many combinations of characteristics, this specific set of projects may
have done little to reduce the storm’s impacts in much of the greater New Orleans area.
Possible Effect of the Hurricanes on Restoration Efforts
Katrina had greater adverse effects on the wetlands being created at the diversion at
Caernarvon than at Davis Pond. The Caernarvon area is estimated to have lost about
25,000 wetland acres. As the diversion is currently operated, it would take many decades
to offset the lost acres. If the diversion was enlarged or its operation modified to increase
the inflow of sediments, the restoration period could be shortened. Some are talking
about a goal of restoring 1,000 to 2,000 acres a year.
The impact from the hurricanes has greatly expanded 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 Louisiana, neither
hurricane respected political boundaries. Katrina caused extensive damage in coastal
Mississippi and Alabama, and Rita caused less extensive damage in eastern Texas. These
distributions of impact may create interest in considering a restoration program that would
provide benefits across the central Gulf Coast. A second aspect is renewed discussion of
projects that would result in larger changes across coastal Louisiana. 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. A third
aspect is a renewed interest in determining which projects would be most effective. A
January 2006 report by a group of recognized experts, primarily from academia, states that
project priorities should be based on storm damage reduction and ecosystem restoration

to develop a “sustainable coastal landscape.”³ This report endorses the development of
a detailed project map that had been recommended in the NRC report.
Even if the 110^th Congress authorizes a substantial restoration effort, 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 is not anticipated to be completed
for about a decade after it is fully funded. For diversion projects, actual reestablishment
of wetlands requires many additional years after the diversion starts to operate. Beyond
the initial five projects, most of the others are much earlier in the planning process, and
therefore completion would be even further into the future. If it is decided to follow the
recommendation of the NRC, the time line for this effort could be further extended.
Ecosystem restoration goals may be in competition with other demands for federal
resources generally, and Corps resources specifically, in coastal Louisiana. These
demands include flood protection, navigation improvements, and housing. It may be too
expensive to fully support all these goals 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? It appears that little that was proposed in the water resources
legislation in the 109^th Congress 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, nor would the many additional projects that were in the Coast 2050
Plan be likely to have had a significant mitigating effect on the flooding associated with
Hurricane Katrina.
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. Such a decision could reduce restoration efforts that could have a
more significant moderating effect on hurricane-related threats 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 it authorizes and funds, which pending legislation does not do. 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.
Congress directed the Corps to develop options for a post-hurricane rebuilding plan
called the Louisiana Coastal Protection and Restoration Plan. In this plan, announced in
the March 3, 2006, Federal Register, the Corps identified four combinations of structural
and nonstructural measures that would protect coastal Louisiana against a category 5
storm. Central issues include (1) what role(s) restoration projects would play in such a
plan, (2) how restoration projects would be integrated with structural measures, and (3)
how projects to protect the New Orleans urban area and to restore coastal Louisiana could
be most effectively integrated. Both versions of the pending legislation would create a
federal-state task force to examine these types of questions.

³ Working Group for Post-Hurricane Planning for the Louisiana Coast, A New Framework for
Planning the Future of Coastal Louisiana after the Hurricanes of 2005 (Final Draft).