Protecting New Orleans: From Hurricane Barriers to Floodwalls

CRS Report for Congress
Protecting New Orleans:
From Hurricane Barriers to Floodwalls
Updated January 26, 2006
Nicole T. Carter
Analyst in Environmental Policy
Resources, Science, and Industry Division


Congressional Research Service ˜ The Library of Congress

Protecting New Orleans:
From Hurricane Barriers to Floodwalls
Summary
Breached floodwalls in downtown New Orleans during Hurricane Katrina
caused significant flooding. Unlike most of the flooding in coastal Louisiana which
resulted from water flowing over levees and floodwalls as the storm’s surge exceeded
the structures’ height, preliminary evidence suggests that three downtown New
Orleans breaches occurred before their design was exceeded. That is, these
downtown breaches resulted not from structures weakened by overtopping, but from
the failure of the floodwalls and their foundations. Findings of ongoing investigations
into the causes of the floodwall failures have implications for analyzing both the
reliability of the existing system of levees and floodwalls and its repairs, and options
for greater structural protection of New Orleans. Moreover, these findings may shape
plans for rebuilding sections of the city and perspectives on the federal role and
responsibility in the city’s rebuilding efforts.
One possible cause of the failure is a poor or inadequate design. Following
Hurricane Betsy in 1965, Congress authorized the Corps to construct with local levee
districts the Lake Pontchartrain and Vicinity Hurricane Protection Project to protect
the city from the rough equivalent of a Category 3 storm. The project’s original
design was to control storm surge flowing into water bodies near downtown by
building inlet barriers and canal floodgates. During the project’s construction which
was ongoing when Hurricane Katrina made landfall, numerous factors (e.g.,
including local environmental concerns, changing cost estimates, local flood
protection preferences, and litigation) contributed to changing how the city was to be
protected; the final design attempted to reduce hurricane-related flooding in the city
by increasing the height of levees and floodwalls, in lieu of the inlet barriers and
canal floodgates.
This report documents the evolution in the design of the Lake Pontchartrain
project, with specific reference to how and by whom design decisions were made.
The focus is on two major design developments relevant to the current investigations
into floodwall failures in downtown New Orleans: (1) the shift from barriers at Lake
Pontchartrain’s inlets to higher levees along the lakeshore; and (2) the shift from
floodgates at the mouth of the city’s stormwater outfall canals that drain into Lake
Pontchartrain to higher floodwalls along the length of the canals.
The Corps’ decision in the mid-1980s to recommend higher levees instead of
the inlet barriers it had recommended in 1965 was shaped by multiple factors,
including environmental litigation, project economics, and local preferences. The
Corps preferred floodgates to floodwalls along the Orleans Avenue and London
Avenue canals. The decision to not build floodgates, and instead build floodwalls
along the canals, was made by local project sponsors. The original design and the
final design were intended to provide the same level of protection, i.e., protection
from the rough equivalent of a Category 3 storm surge. This report will be updated
as events warrant.



Contents
In troduction ..................................................1
New Orleans Hurricane Protection ................................3
Hurricane Katrina’s Floodwall Breaches: A Primer...............3
Lake Pontchartrain Project..................................4
Choosing Higher Levees over Inlet Barriers.....................5
Choosing Improved Canal Levees and Floodwalls over Floodgates...7
Current Issues and Conclusion....................................9
Appendix: Lake Pontchartrain Project Federal Funding — 1965-2006.......12
List of Figures
Figure 1. New Orleans Hurricane Protection with Hurricane Katrina Breaches
and Flooding.................................................4
Figure 2. Rejected Inlet Barriers and Canal Floodgates....................7
List of Tables
Table 1. Lake Pontchartrain and Vicinity Project: Federal Construction
Funding History..............................................13



Protecting New Orleans:
From Hurricane Barriers to Floodwalls
Introduction
New Orleans’ location on the Gulf Coast with water on three sides and below-
sea-level terrain makes this densely populated section of Louisiana highly susceptible
to flooding from hurricane storm surges. New Orleans’ flooding threats are not only
from the coast but also from the Mississippi River and rainfall that gets trapped in the
city, known as stormwater. The system of levees and floodwalls around the city is
designed to provide a specified level of protection from riverine and coastal flooding;
where as, massive pumps and drainage canals that flow into Lake Pontchartrain1
manage the city’s stormwater. Local levee districts maintain the hurricane levees
and floodwalls that were built largely by the U.S. Army Corps of Engineers as part
of its Lake Pontchartrain and Vicinity Hurricane Protection Project to protect New
Orleans and the surrounding parishes from a Category 3 hurricane. The Sewerage
and Water Board of New Orleans is responsible for the city’s stormwater
management infrastructure.
Breaches of the floodwalls protecting New Orleans during Hurricane Katrina
were the major contributor to significant flooding in many areas of downtown.
Although most of the levee breaches in coastal Louisiana were the result of the
storm’s surge flowing over levees, preliminary evidence suggests that three major
breaches in downtown New Orleans occurred prior to the floodwalls being
overtopped; that is, the floodwalls failed before their design was exceeded. The
failure of these floodwalls to reliably perform has many stakeholders’ speculating
about the causes of the failures.
A question central to many of the investigations into Katrina-related damage and
of concern in rebuilding efforts is: were the levees and floodwalls breached because
their design was exceeded, or did they fail due to faulty design, construction, or
maintenance? To answer these questions, evidence has and continues to be collected
on numerous fronts, including evidence of the height of the storm surge in various
locations, and how the levees and floodwalls performed. Technical experts from
universities, professional engineering organizations, and the Corps are using this
evidence to model and explain the performance of New Orleans’ hurricane protection
system. The findings are likely to shape not only the future design of the hurricane
protection system but also plans for rebuilding sections of the city and perspectives
on the federal role and responsibility in the city’s rebuilding efforts. Moreover, the


1 Levees are broad, earthen structures, while floodwalls are concrete and steel walls, built
atop a levee or in lieu of a levee. Floodwalls are often used in urban areas because they
require less land than levees.

findings may improve understanding and change perceptions of the level of flood
protection and risk in other U.S. cities.
Understanding why New Orleans’ hurricane protection system failed is essential
for moving beyond simply making repairs to damaged levees and floodwalls.
Knowing why the floodwalls failed is central to assessing the city’s vulnerability to
storm surge flooding and deciding on how to most effectively combine approaches
for managing flood risk during rebuilding efforts (e.g., investing in coastal wetlands
loss and hurricane protection infrastructure, requiring flood-proofing in certain areas,
and mapping areas for the federal flood insurance program). Nonetheless in order
to be prepared for the 2006 hurricane season, the Corps is having to proceed with
immediate repairs of damaged levees and floodwalls using available information and
integrating new information as it is available.
One of the causes of failure being discussed is a poor or inadequate design for
protecting the city from a Category 3 hurricane. The original project design was to
control storm surge flowing into water bodies near downtown by building inlet
barriers and canal floodgates. During the project’s construction which began with
authorization in 1965 and was ongoing when Hurricane Katrina made landfall,
numerous factors contributed to changing the design of how to protect the city (e.g.,
including local environmental concerns, changing cost estimates, local flood
protection preferences, and litigation); the final design attempted to reduce hurricane-
related flooding in the city by increasing the height of levees and floodwalls, in lieu
of the barriers and floodgates.
The Corps’ decision in the mid-1980s to recommend higher levees instead of
the inlet barriers it had recommended in 1965 was shaped by multiple factors,
including environmental litigation, project economics, and local preferences. The
Corps preferred floodgates to floodwalls along the Orleans Avenue and London
Avenue canals. The decision to not build floodgates, and instead build floodwalls
along the canals, was made by the local project sponsors. The original design and the
final design were intended to provide the same level of protection, i.e., protection
from the rough equivalent of a Category 3 storm surge.
This report discusses the evolution in the project’s design, with specific
reference to how and by whom design decisions were made. The focus is on two
major design developments relevant to the current investigations into the floodwall
failures in downtown New Orleans’ during Hurricane Katrina: (1) the shift from the
barriers at the inlets to Lake Pontchartrain to higher levees along the lake; and (2) the
shift from floodgates at the mouth of the city’s stormwater outfall canals that drain
into Lake Pontchartrain to higher floodwalls along the length of the canals. The
report includes an appendix summarizing the federal funding history for the Lake
Pontchartrain project. The analysis contained herein is based on currently available
information and is limited in scope.2


2 Many of the documents referenced in this report are available online at a site maintained
by the Corps [https://ipet.wes.army.mil]. Because this site has many documents that cannot
be hyperlinked, please contact CRS for assistance in locating specific documents. Factors
(continued...)

New Orleans Hurricane Protection
Hurricane Katrina’s Floodwall Breaches: A Primer. Although there
were more than a dozen breaches and many other segments of damaged levees and
floodwalls in the greater New Orleans area and numerous in other coastal Louisiana
parishes, the four breaches (see Figure 1) of the Lake Pontchartrain project that have
received the greatest attention due to their impact on downtown New Orleans were
the following:
!a breach of the 17th Street Canal floodwall;
!two breaches of the London Avenue Canal floodwall; and
!a breach of the western flank of the Inner Harbor Navigation Canal
(IHNC, also known as the Industrial Canal) floodwall.
Flooding due to overtopping of city’s levees and floodwalls was predicted for
storm surges from a storm stronger than a Category 3 hurricane passing close to the
New Orleans region.3 Extensive overtopping may cause a levee or floodwall breach.
Breaching in urban areas often produces catastrophic damage. Hurricane Katrina had
weakened from a Category 5 storm to a Category 4 storm by the time passed east of
New Orleans. Overtopping was the cause of much of the flooding and most of the
breaches and damage to the hurricane protection infrastructure in coastal Louisiana.
However, overtopping does not appear to have caused much of the flooding and
some of the breaches in downtown New Orleans.
A November 2005 preliminary analysis of the performance of New Orleans’
hurricane protection system by technical expert teams from the University of
California at Berkeley and the American Society of Civil Engineers indicate the4
method of failures at the breaches in downtown New Orleans. The teams’
preliminary evidence suggests that breaches along the 17th Street and London Avenue
canals occurred before the floodwalls were overtopped; that is, these floodwalls
failed before their design was exceeded. The immediate and underlying causes of
these breaches (i.e., what led to the failures) are the subject of conjecture; hypotheses


2 (...continued)
that are often debated in the discussions of the performance during Hurricane Katrina of the
Lake Pontchartrain project and other levees in coastal Louisiana (e.g., levee maintenance,
operation of the Mississippi River Gulf Outlet (MRGO) deep-draft navigation channel, loss
of coastal wetlands, and increasing sea surface temperature) are not discussed in this report.
The many other breaches of the Lake Pontchartrain project (such as the breaches on the
eastern flank of the IHNC that contributed to the flooding of the Lower Ninth Ward) and
levees constructed as elements of other U.S. Army Corps of Engineers (Corps) and local
projects also are not discussed.
3 Hurricane Categories are based on the Saffir-Simpson Hurricane Scale of 1-5, with
Category 4 storms having 131-155 mile per hour (mph) winds and a 13- to 18-foot storm
surge, and Category 5 storms having winds exceeding 155 mph and surges above 18 feet.
4 R.B. Seed, et al., Preliminary Report on the Performance of the New Orleans Levee
Systems in Hurricane Katrina on August 29, 2005 (Berkeley, CA: University of California
Berkeley and American Society of Civil Engineers, November 2, 2005), available at
[http://hsgac.senate.gov/_files/Katrina/Preliminary_Report.pdf], visited Jan. 26, 2006.

range from exceeded design, poor design, faulty construction, maintenance issues,
incomplete construction due to the level of construction appropriations (see the
Appendix for information on the project’s federal funding), and modifications to the
project’s original design. The Corps has initiated a forensic investigation of the
floodwall breaches; the results are expected in June 2006. According to the teams’
preliminary analysis, the combined storm surges from several direction along the
IHNC and the Mississippi River Gulf Outlet (MRGO) overtopped the IHNC and
MRGO.
Figure 1. New Orleans Hurricane Protection with Hurricane Katrina
Breaches and Flooding


Source: National Oceanic and Atmospheric Administration; Federal Emergency Management
Agency; U.S. Army Corps of Engineers. Prepared by the Congressional Cartography Program,
Geography and Map Division, Library of Congress, 2005.
Lake Pontchartrain Project. Congress authorized the Corps to protect New
Orleans from the rough equivalent of a Category 3 storm when it authorized the Lake
Pontchartrain and Vicinity Hurricane Protection Project in October1965.5 The
project consists of levees and floodwalls, most of which were constructed by the
5 The Lake Pontchartrain project included structures in St. Charles (located west of
Jefferson Parish, not shown in Figure 1), Jefferson, Orleans, and St. Bernard Parishes. In
1999, the House Committee on Transportation and Infrastructure authorized, via a
Committee Resolution, a Hurricane Protection Louisiana study to investigate
providing hurricane protection from a Category 4 or 5 storm.

Corps and cost-shared by the federal government and local levee districts.6 The
Orleans Parish segments of the Lake Pontchartrain project, which encompass
downtown New Orleans, were 90% complete as of May 2005. The total cost for the
Lake Pontchartrain and Vicinity project is $738 million, with the federal
responsibility $528 million.7 Federal allocations totaled $457 million through
FY2005, leaving around $70 million to complete federal funding.
The original design of the Lake Pontchartrain project was sent to Congress in
July 1965. The project was designed to protect the city from a standard hurricane for
the region, which was roughly equivalent to a Category 3 hurricane on the Saffir-
Simpson Scale. The standard hurricane was defined as high sustained wind speeds
reasonably characteristic for a specified coastal location. Reasonably characteristic
was defined as only a few hurricanes on record over the general region had been
recorded to have more extreme wind and other meteorological characteristics. The
standard hurricane was determined by the U.S. Weather Service.
Two months later in September 1965, Hurricane Betsy, a Category 3 hurricane,
struck Louisiana’s coast, causing damage in New Orleans. Congress authorized
construction of the Lake Pontchartrain project in the Flood Control Act of 1965,
enacted in October 1965. Modifications to the authorization have been made in
subsequent legislation. Since that original design, there have been two major
developments in the project relevant to current investigations into the floodwall
failures: (1) the shift from the barriers at the inlets to Lake Pontchartrain to higher
levees along the lake; and (2) the shift from floodgates at the mouth of the city’s
stormwater outfall canals that drain into Lake Pontchartrain to higher floodwalls
along the length of the canals. These two decisions are discussed below.
Choosing Higher Levees over Inlet Barriers. The original July 1965
Lake Pontchartrain project design consisted of the Barrier Plan for constructing inlet
barriers at Lake Pontchartrain’s three main tidal entrances as well as levees and
floodwalls for surge protection. The barriers generally would remain open and allow
for navigation, and would close during coastal storms to reduce storm surges from8
entering the lake. Based on updated weather data and experience learned during the
city’s flooding in September 1965 by Hurricane Betsy, changes in the project were
sought before construction began. For almost 2 decades, technical issues,


6 The Corps was responsible for most, but not all, of the construction of the Lake
Pontchartrain project; the Lake Pontchartrain project often was built atop existing levees
constructed by locals or as part of earlier federal projects.
7 Most Corps storm damage reduction construction projects are cost-shared 65% federal and

35% non-federal. Operation and maintenance of these projects generally is a 100% non-


federal responsibility.
8 U.S. Congress, House, Lake Pontchartrain and Vicinity, Louisiana, H. Doc. No. 231
(GPO: July 6, 1965). The three barriers in the Barrier Plan were the Seabrook Lock for
navigation and flood protection, Menteur Pass gates for navigation and flood protection, and
Rigolets floodgates and navigation lock. The Barrier Plan also would have included higher
levees along the northwestern edge of Lake Borgne as part of the inlet controls to Lake
Pontchartrain.

environmental concerns, legal challenges, and local opposition to various
components slowed construction.
The design that the Corps eventually chose was the High-Level Plan which
consists of higher levees and floodwalls, instead of the originally planned inlet
barriers and lower levees and floodwalls. (Figure 2 shows the existing hurricane
protection infrastructure as well as the elements of the Barrier Plan that were rejected
in favor of higher levees and floodwalls.) The change from the Barrier Plan to the
High-Level Plan was approved by the Corps’ Chief of Engineers in February 1985;
both the barrier and the high-level plans were designed to protect from the rough9
equivalent of a fast-moving Category 3 hurricane. The Chief’s decision to adopt the
High-Level Plan was based on a 1984 project reevaluation study conducted by the
agency in response to a 1977 court injunction on the construction of inlet barriers
until an adequate Environmental Impact Statement (pursuant to the National10
Environmental Policy Act of 1969 P.L. 91-190) was completed. The re-evaluation
study recommended the change because “the High Level Plan has greater net
benefits, is less damaging to the environment, and is more acceptable to the public”
than the Barrier Plan.11


9 Corps, Lake Pontchartrain, Louisiana, and Vicinity Hurricane Protection Project:
Reevlauation Study (New Orleans: July 1984). (Hereafter cited as Corps, Lake
Pontchartrain, Louisiana, and Vicinity Hurricane Protection Project.) According to the
1984 re-evaluation study, the design storm for protection bordering Lake Pontchartrain had
a return frequency of approximately 300 years. The return frequency of the design critical
to other project areas, such as Inner Harbor and New Orleans East Bank Levees, was
approximately 200 years.
10 For more information on the injunction, see CRS Report RL33104, NEPA and Hurricane
Response, Recovery, and Rebuilding Efforts, by Linda Luther.
11 Corps, Lake Pontchartrain, Louisiana, and Vicinity Hurricane Protection Project.

Figure 2. Rejected Inlet Barriers and Canal Floodgates


Source: National Oceanic and Atmospheric Administration; Federal Emergency Management
Agency; U.S. Army Corps of Engineers. Prepared by the Congressional Cartography Program,
Geography and Map Division, Library of Congress, 2005.
Choosing Improved Canal Levees and Floodwalls over Floodgates.
To drain the city of stormwater (i.e., accumulated rainfall), the city pumps water intoth
three outfall canals — the 17 Street canal, the Orleans Avenue canal, and the
London Avenue canal — that flow into Lake Pontchartrain. The pumps are located
at the southern ends of the canals, away from the lake. To protect the city from rising
water in Lake Pontchartrain during hurricanes, levees were built along the length of
the canals. The levees along the outfall canals were considered adequate when the
Corps developed the original design for the Lake Pontchartrain project that was sent
to Congress in July 1965.
Subsequent to the U.S. Weather Bureau’s adoption of a more severe standard
hurricane for the region, the Corps determined that the levees along the outfall canals
were inadequate in their height and stability to protect the city from the standard
hurricane. The Corps eventually integrated hurricane storm protection for the canals
into its Lake Pontchartrain project. The Corps considered Improved canal protection
necessary regardless of the selection of the Barrier or High-Level Plan. The two
basic canal options evaluated were:
!“butterfly” floodgates at the mouths of the outfall canals that would
close when water levels in Lake Pontchartrain exceeded levels in the
canals (known as fronting protection); and

!higher and stronger levees and floodwalls along the canals (known
as parallel protection).
The Orleans Levee District and the Sewerage and Water Board of New Orleans
favored parallel protection over floodgates; they were concerned that the operation
of the butterfly floodgates would reduce the ability to pump stormwater out of the
city during storms. The Corps analyzed the options and recommended parallel
protection for the 17th Street Canal;12 in contrast, the Corps recommended butterfly
floodgates for the Orleans and London Avenue canals. The Corps concluded that the
butterfly floodgate plan for the London Avenue canal
fully satisfies the project’s mandate to provide protection against the hurricane
generated tidal surges and yet provides the maximum latitude for operation of
local interest interior drainage [i.e., stormwater removal]. The butterfly control
valve plan has been shown to be the least costly fully responsive plan. When
compared to the parallel protection plan it is approximately three times less13
costly.
The conclusion for the Orleans Avenue canal was similar; the Corps found the
butterfly gates to fully satisfy the project purpose of hurricane storm surge protection
and to be one-fifth the cost of parallel protection.14
Rather than having the Corps proceed with construction of the butterfly
floodgates, the Orleans Levee District decided to construct on its own most elements
of the parallel protection on the Orleans and London Avenue canals. This local
construction was designed in accordance with Corps criteria, so that the parallel
protection would be incorporated into the larger Lake Pontchartrain project. (Figure
2 shows the existing hurricane protection infrastructure as well as the canal
floodgates that were rejected in favor of higher canal levees and flood walls.) The
Corps recommended that the federal cost-share contribution for the parallel
protection of the two canals be capped at 70% of the less-costly butterfly floodgates
design. (The Lake Pontchartrain project was authorized in 1965 based on a
construction cost share of 70% federal - 30% nonfederal. See the Appendix for a 40-
year history of the federal construction funding.) In H.Rept. 101-966, the Conference
Report for the Water Resources Development Act (WRDA) of 1990 (P.L. 101-640),
Congress directed the Corps to consider favorably parallel protection for the two
canals and for the federal government to bear part of the costs, but did not specify


12 Corps, Lake Pontchartrain High Level Plan, Design Memorandum No. 20, 17th St. Outfall
Canal (New Orleans: March 1990).
13 Corps, Lake Pontchartrain High Level Plan, Design Memorandum No. 19A: London
Avenue Outfall Canal (New Orleans: January 1989).
14 Corps, Lake Pontchartrain High Level Plan, Design Memorandum No. 19: Orleans
Avenue Outfall Canal (New Orleans: August 1988).

what percentage of the cost.15 This report was followed by the Energy and Water
Development Appropriations Act of 1992 (P.L. 102-104) in which Congress stated:
The Secretary of the Army is authorized and directed to provide parallel
hurricane protection along the entire lengths of the outfall canals and other
pertinent work necessary to complete an entire parallel protection system, to be
cost shared as an authorized project feature, the Federal cost participation in
which shall be 70 percent of the total cost of the entire parallel protection system,
and the local cost participation in which shall be 30 percent of the total cost of
such entire parallel protection system.
Current Issues and Conclusion
In summary, the original project design aimed to control storm surge flowing
into water bodies around downtown New Orleans using inlet barriers and canal
floodgates (in combination with levees). The constructed project, however,
attempted to reduce the city’s flooding from water bodies affected by hurricane storm
surge and wind through higher levees and floodwalls. The Corps’ decision to
recommend higher levees instead of inlet barriers was shaped by multiple factors,
including environmental litigation, project economics, and local preferences. The
Corps preferred floodgates to floodwalls along the Orleans Avenue and London
Avenue canals. The decision to not build floodgates, and instead build floodwalls
along the canals, was made by the local project sponsors. The original design and the
final design were intended to provide the same level of protection, i.e., protection
from the rough equivalent of a Category 3 storm surge.
Hurricane Katrina’s storm surge overtopped and breached New Orleans’
hurricane protection system. In addition to causing extensive flood in downtown
New Orleans, the floodwall failures decreased confidence in the reliability of the
existing hurricane infrastructure to protect the city from Category 3 and less-severe
hurricanes.
Confidence in both the reliability of hurricane infrastructure and the level of
protection provided by natural and constructed hurricane protection is a factor
shaping near-term and long-term investment decisions, as residents and businesses
decide whether and how to rebuild. (For an analysis of wetlands restoration
opportunities, see CRS Report RS22276, Hurricanes Katrina and Rita and the
Coastal Louisiana Ecosystem Restoration, by Jeffrey Zinn.) In the near-term, many
are concerned with the level of protection that will be available at the start of the
2006 hurricane season. By June 2006, the Corps expects to have completed its repairs
of the existing infrastructure. However, the findings from the Corps’ investigation
into the causes of the floodwall failures are not anticipated until June 2006, raising
the question of whether the agency will be able to respond to the findings and


15 The report directed “the Corps to treat the outfall canals as part of the overall hurricane
protection project, and to favorably consider a plan that raises the levees along the entire
lengths of the London Avenue and Orleans Avenue Canals to grades sufficient to confine
a standard project hurricane with costs borne by both Federal and local assuring authorities.”

improve the floodwalls’ reliability when repairing the damaged levees and floodwalls
for the 2006 hurricane season in June 2006.16
Concerns about levee and floodwall reliability are compounded by concerns
about the level of protection provided by the existing infrastructure given New
Orleans’ increasing vulnerability to hurricane storm surge. Land in the city has
subsided; barrier islands and wetlands have been disappearing;17 and sea levels have
risen. These factors have raised concerns about the ability of the city’s infrastructure
to provide Category 3 protection. According to the project justification sheet
included in the Administration’s Corps FY2006 budget request, “the project was
initially designed in the 1960s, and a reanalysis was performed for part of the project
in the mid-1980s. Continuing coastal land loss and settlement of land in the project
may have impacted the ability of the project to withstand the design storm.”18 The
challenge of protecting New Orleans could become even greater. According to some
scientists, higher sea surface temperatures may result in increased hurricane
intensity.19 Climate change concerns and other factors have raised questions about
whether both estimates of the likelihood of hurricanes of various strengths and past
infrastructure investment decisions based on these estimates need to be re-evaluated.
Hurricane Katrina has resulted in some questioning why a Category 4 or 5
hurricane protection system was not in place for New Orleans, and whether it should
be part of the rebuilding effort. The Corps currently only has congressional
authorization for a Category 3 system; additional congressional authorization would
be necessary to build a more protective system. Discussions of Category 4 or 5
protection for the city often include the extent to which coastal wetlands restoration
may play a role in reducing the city’s vulnerability to storm surge and whether some
of the regional navigation improvements may increase storm surge vulnerability.
These discussions raise broader policy issues related to the appropriate level of
investment to protect against low probability-high consequences events; to protect
against loss of life and economic disruption; and whether structural storm and flood
control measures provide a false sense of security in vulnerable areas like New
Orleans. The Corps’ cost estimates are $1.6 billion to return coastal Louisiana’s
federal levees and floodwalls to pre-Katrina conditions by June 2006, and an


16 The Corps has indicated that the agency’s team working on the investigation will be
communicating interim results to the repair team.
17 For information on coastal wetlands loss, see CRS Report RL32673, Coastal Louisiana:
Attempting to Restore an Ecosystem, by Jeffrey Zinn.
18 U.S. Army Corps of Engineers, Fiscal Year 2006, Mississippi Valley Division, visited
Jan. 26, 2006, available at
[http://www.usace.army.mil/inet/functions/cw/ cecwb/j ust_states06/mvd.pdf].
19 For example, see Intergovernmental Panel on Climate Change, Climate Change 2001:
Working Group II: Impacts, Adaptation and Vulnerability, visited on Jan. 26, 2006,
available at
[http://www.grida.no/climate/ipcc_tar/wg2/029.htm], or T.R. Knutson and R.E. Tuleya,
“Impact of CO2-Induced Warming on Simulated Hurricane Intensity and Precipitation:
Sensitivity to the Choice of Climate Model and Convective Parameterization,” Journal of
Climate, c. 17, no. 18 (Sept. 15, 2004), available at [http://www.gfdl.noaa.gov
/reference/bibliogr aphy/2004/tk0401.pdf].

additional $3.5 billion to increase protection for New Orleans from Category 3 to
Category 5. State officials have estimated the cost of Category 5 protection and
wetlands restoration for all of coastal Louisiana as high as $32 billion. Most local
stakeholders argue for the inclusion of coastal wetlands restoration in any plan to
improve hurricane protection.
Neither a consensus nor proposed plans on how to improve hurricane protection
for New Orleans or costal Louisiana in the aftermath of Hurricane Katrina have
emerged. Discussions continue about the advantages and disadvantages of additional
infrastructure compared to other policy options, such as protection and restoration of
wetlands that attenuate storm surges, buyouts of structures on the most flood-prone
lands, flood-proofing structures, and improvements to the flood insurance program.
For a discussion of managing flood risks, see CRS Report RL33129, Flood Risk
Management: Federal Role in Infrastructure, by Nicole T. Carter.
Understanding why the hurricane protection system failed in New Orleans is
essential to moving beyond simply making repairs, to identifying and reducing
vulnerabilities in the system, addressing coastal wetlands loss, and rebuilding the
city. Nonetheless, the Corps is having to proceed with available information in order
to perform repairs to the failed floodwalls and other breaches to meet the June 2006
deadline, which marks the start of the hurricane season. Consequently, congressional
oversight of New Orleans’ hurricane protection is likely to continue as the nation
grapples with decisions on what type and level of hurricane protection to provide
New Orleans and other coastal areas around the nation, and who should bear
responsibility and costs for protection in coastal, floodplain, and other hazard-prone
areas.



Appendix: Lake Pontchartrain Project Federal
Funding — 1965-2006
Table 1 provides the federal funding history for the constructions of the Lake
Pontchartrain project. This information was provided to CRS by the Army Corps
of Engineers. Table 1 does not include project funding by non-federal project
sponsors which are responsible for 30% of construction expenses and 100% of
maintenance costs.
The Initial Work Allowance column represents the final enacted amount; this
amount differs from the amount shown for the Lake Pontchartrain line item in
appropriations conference reports due to rescissions and other reductions made by
Congress. The Corps has some authority to reprogram funds across construction
projects during the fiscal year; the Year End Work Allowance represents the Initial
Work Allowance and any reprogrammings that occurred, which are shown in the
Transferred Funds column. A negative in the Transferred Funds column indicates
funds were reprogrammed away from the Lake Pontchartrain project during the
fiscal year.
Beginning with the Fiscal Year 1994 Budget Justification, the Corps stopped
scheduling the Orleans Avenue and London Avenue components of the Lake
Pontchartrain project as part of its annual budget request. As shown in Table 1,
Congress provided more than requested for the Lake Pontchartrain project by the
Administration. Some of these funds may have been used to construct parallel
protection for Orleans Avenue and London Avenue canals; however, CRS was not
able to determine the federal funding level for the Orleans Avenue and London
Avenue parallel protection based on currently available information. When
Hurricane Katrina hit, the floodwalls along all three canals were complete; the canal
work that remained to be built was the floodproofing of bridges (that is, the extension
of a floodwall across a bridge to connect with a floodwall on the other side) and the
extension of floodwalls across the front of pumping stations.



Table 1. Lake Pontchartrain and Vicinity Project:
Federal Construction Funding History
(in thousands, nominal dollars)
President’sInitial workYear-end workTransferred
Fiscal yearbudget requestallowance allowancefunds
2006 2,977 na na na
2005 3,937 5,081 4,945 -136
2004 3,000 4,694 7,206 2,512
2003 4,900 5,708 10,082 4,374
2002 7,500 11,972 9,484 -2 ,488
2001 3,100 8,380 14,295 5,915
2000 11,887 14,482 26,204 11,722
1999 5,676 16,000 16,000 0
1998 6,448 22,920 22,920 0
1997 4,025 17,025 17,025 0
1996 7,848 13,348 13,348 0
1995 10,000 13,300 13,300 0
1994 9,619 24,319 28,619 4,300
1993 11,607 18,194 19,160 966
1992 21,491 18,295 9,852 -8 ,443
1991 11,655 10,524 -4 ,989 -15,513
1990 39,898 35,639 32,882 -2 ,757
1989 40,400 36,384 9,214 -27,170
1988 17,000 14,784 13,140 -1 ,644
1987 16,000 15,375 13,375 -2 ,000
1986 25,000 20,288 20,358 70
1985 17,500 15,100 11,158 -3 ,942
1984 16,800 15,800 8,800 -7 ,000
1983 na 14,800 13,716 -1 ,084
1982 15,000 15,000 13,000 -2 ,000
1981 10,800 9,600 8,800 -800
1980 11,000 10,000 13,320 3,320
1979 0 0 230 230
1978 12,400 10,000 7,500 -2 ,500
1977 12,000 10,700 10,575 -125rd
1976 & 3 Qtr.29,35019,98515,980-4,005
1975 3,300 2,100 -2 ,080 -4 ,180
1974 6,400 0 2 ,660 2,660
1973 20,000 17,500 14,840 -2 ,660
1972 4,555 10,946 13,946 3,000
1971 8,250 11,250 11,040 -210
1970 6,000 8,050 5,260 -2 ,790
1969 7,800 6,274 6,269 -5
1968 2,300 4,000 4,086 86
1967 450 1,600 1,600 0
1966 0 450 0 -450
1965 0nanana
To t a l 447,873 509,867 457,120 -52,747
Source: Data provided by Army Corps of Engineers, 2005.
na = not available