essay levees draft 1

Loyola University New Orleans Policy Research Shop College of Social Sciences, Political Science Department___________________________________________________________

Hurricane and Flood Protection in New Orleans___________________________________________________

PRS Policy Brief 15 December 2011

Prepared by:Martin Antonio Quintero, Melisa Mantilla and Jerry Reese

This report was written by undergraduate students at Loyola University New Orleans under the direction of Professor Peter F. Burns.

Contact:Dr. Peter F. Burns ∙ [email protected] ∙ 504-865-2299

Loyola University New Orleans ∙ 6363 St. Charles Avenue ∙ Box 86 ∙ New Orleans, Louisiana 70118

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TABLE OF CONTENTS

EXECUTIVE SUMMARY................................................................................................................3

INTRODUCTION.............................................................................................................................4

THE LEVEE SYSTEM BEFORE HURRICANE KATRINA...........................................................5

THE CURRENT PROBLEM WITH THE LEVEE SYSTEM...........................................................6

LACK OF STANDARDS..............................................................................................................6

DEFINING SAFETY.....................................................................................................................8

THE PROBLEM............................................................................................................................9

THE NETHERLANDS—DUTCH FLOOD PROTECTION SYSTEM...........................................11

CALIFORNIA VALLEY FLOOD PROTECTION.........................................................................16

RECOMMENDATIONS.................................................................................................................20

APPENDIX:.....................................................................................................................................23

WORKS CITED..............................................................................................................................25

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EXECUTIVE SUMMARY

Hurricane Katrina was the most destructive and costly of natural disaster in the

history of the United States. Hurricane Katrina revealed the failure of the hurricane

protection system and the poor performance and slow response of the government during

the disaster. The paper focuses on explaining why the hurricane protection system failed

and how the lack of standards for measuring safety is the main problem that the levee

system faces today. Using a set of standards developed from the research, we were able to

propose the courses of action that New Orleans should undertake to improve its’ flood

protection system.

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INTRODUCTION

Hurricane Katrina was the focusing event that revealed a problem that had been

overlooked, the failure of the levee system and the lack of an efficient emergency response

by the government. In August 29, 2005, a Category 3 storm hit New Orleans leaving behind

1500 dead and 100 000 homeless. Most of New Orleans was flooded, with the Orleans and

St. Bernard Parishes flooded more than 80%. The devastation caused by the event revealed

the importance and necessity of a safe levee system and the risks of living in an area

unprotected of hurricanes and flooding. The levee system has been restored to withstand a

100-year flood. However, this is not a standard for safety. Hence, the main challenge that

the levee system faces is the lack of standards that would determine whether it is or not a

safe system. The Netherlands and California served as successful examples of a safe flood

protection system. Therefore, the purpose of the New Orleans’ hurricane and flood

protection system is to reduce the risks and provide safety for those living behind the levee

system.

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THE LEVEE SYSTEM BEFORE HURRICANE KATRINA

New Orleans geographical makes the city vulnerable to hurricanes, as most of its

population lives in the areas below sea level that are most prone to flooding. In addition,

human activities have disrupted the environment, increasing the rates of erosion of

wetlands and marshes. As a result, the populated areas are being increasingly exposed to

the Gulf of Mexico.

Under the Flood Control Act of 1965, Congress ordered the Corps of Engineers to

protect New Orleans from “the most severe meteorological conditions considered

reasonably characteristic for that region” (Van Heerden, 25). However there was no way to

determine if levees where appropriate for the most severe meteorological conditions. This

Hurricane Protection System was never completed and the design that was originally

planned to take 13 years stretched out over 40 years. During these 40 years, “changes to the

definition of sea level, actual subsidence…, settlement, and datum-related issues caused the

top of barriers to be lower than authorized project levels at some locations” (Sills, 563)

Hurricane Katrina was a stronger storm than what the hurricane protection system

was designed to withstand. Breaching and overtopping took place in levees where these

have been in soils with higher silt and sand content. In addition, I-type floodwalls failed,

especially because of the instability in the foundation soils. In contrast, T-type floodwalls

resisted overtopping and erosion.

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THE CURRENT PROBLEM WITH THE LEVEE SYSTEM

LACK OF STANDARDSDuring Hurricane Katrina, more than half of the levees that protect the Greater New

Orleans were breached or destroyed by the hurricane. Since then, the Army Corp of

Engineers has undertaken the responsibility to restore the levee system to satisfy the one-

percent-annual-chance level of flood risk reduction. However, this is not a safety standard.

In 1968 Congress enacted the National Flood Insurance Program which established that the

“ 1%-annual-chance event as a flood hazard area in which those holding federally related

mortgages would be required to purchase flood insurance” (National Committee on Levee

Safety, 10). Gilbert White, a professor at the University of Colorado and widely recognized

advocate of promoting sound US flood management strategies, explained the problem of

using the 100-year flood as the criteria for design. The Federal Insurance Administration

chose this figure because it represented an intermediate level regional flood, and hence

implicitly imposing this figure as a standard. The problem is that the design of the levees

has focused on the 100-year level flood (which is not a standard of safety) and that even

when levees are said to meet this criteria, there is still likelihood of flood as seen on the

graph below.

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The graph demonstrates that even with a 100-year level of flood protection there is

almost 30% of flooding over a period of 30 years. In addition, New Orleans geographical

location makes the city even more vulnerable to flooding. New Orleans needs a levee

system that addresses the flood risks and is designed to resist floods of all magnitudes.

Money is not being managed properly because there is no way to determine how to

allocate the resources. The Federal and state agencies have varying policies and conflicting

criteria regarding design, construction, operation, and maintenance. There are no cohesive

standard for levee safety that can be adopted by governments at all levels. New Orleans

needs to attain a safe flood and hurricane protection system. Yet, without standards to

effectively define and measure safety, it is impossible to identify the flaws in the system,

and allocate resources to improve, provide safety and minimize the risks.

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DEFINING SAFETY There are several important criteria to take into consideration when defining a safe

hurricane and flood protection system. There are some elements that distinguish a safe

system. These standards serve to measure and define safety1:

1. Building Codes:o Implementation of Freeboard Designo Implementation of Closure Design o Implementation of Embankment Protection o Foundation Stability Analyses o Natural protection (wetlands, marshes, barrier islands)o Land use

2. Levee Certification 3. Program Oversight

o Independent review committeeo Periodical assessment of performance o Continuous funding

4. Assessment 5. Research and Development 6. Sustainability 7. Training 8. Risk Communication

o Public involvement o Awareness Campaigns o Emergency Management

An important aspect that distinguishes a safe system is the one that accounts for all the

unknowns in its design. “Engineers address uncertainties in levees by adding freeboard to

raise crown elevation beyond the minimum specified to account for unknowns, and by

incorporating redundant measures to limit the effect of the failure of a single component”

(Van Heerden, 27)

1 See Appendix for definitions and explanations of the criteria. These standards were developed using the criteria used by FEMA in 44 CFR 65.10; the recommendations of the National Committee on Levee Safety to the Congress and the Analyses of the Interagency Performance Evaluation Task Force.

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THE PROBLEMAnalysis performed by the IPET, reveal that “with the current hurricane protection

system, most of the city will be flooded to an extent worse than during Katrina at least once

every 500 years” (Shuster, 16). In addition, there a 10% chance that every 50 years the city

will flood to an extent similar to Katrina.

Using the following standards, one can see that New Orleans has an unsafe flood and

hurricane protection system. Acording to FEMA’s criteria, New Orleans has incorporated

embankment protection, foundation of stability analysis and freeboard design. However,

other important aspects have been overlooked and no action has been taken to address

them.

Also, “population growth and economic investment behind levees is the dominant

factor in the national flood risk outpacing the effects of increased chance of flood

occurrence and the degradation of levees” (National Committee on Levee Safety, 12). The

Census of 2006 showed that two of fastest growing counties in the United States were the

St. Bernard Parish and Orleans Parish. These two areas were the most devastated in the

Greater New Orleans area during Katrina, yet construction and development continues to

take place without land use plan. These areas have low level of flood protection and are areas at

high risk.

Different areas of New Orleans have different levels of flood protection. “However, the

overall level of flood protection is probably on the order of about a 2%-annual chance or

about a 50-year level of flood protection” (National Committee on Levee Safety, 63)

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Building CodesImplementati

on of Embankment

Protection

Natural Protection Foundation of Stability Analyses

Implementation of

Freeboard Design

Land Use

X No natural protection. The

wetlands which act as a natural flood protection have

reduced significantly over the last 50

years.

X X Lack of land use planning. St. Bernard Parish and Orleans Parish, the two areas most devastated areas in the Greater New Orleans, during Katrina, continue to grow and develop. More lives and property are at risk.

Levee Certification

Assessment Research and Development

Sustainability Training

XFEMA

Certified

A review of federal agencies that have responsibilities for levee safety indicates a lack of rigorous oversight.

XModern engineering practices have been applied to the levees.

Program OversightPublic Involvement Periodic Assessment of

PerformanceContinuous Funding

Most of the funds that have been allocated for disaster recovery have been

used to restore the levee system to the 100-year level of flood protection.

Vital repairs are neglected, and these levees are subject to further deterioration

due to lack of funds

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Risk CommunicationIndependent Review

CommitteeAwareness Campaign Emergency Management

To an extent

The Corps has received approximately $15 billion to repair the levees and floodwalls. This flood protection system is expected to attain the 1%-annual chance of flood protection.

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THE NETHERLANDS—DUTCH FLOOD PROTECTION SYSTEM

The modern Flood Protection System in place in the Netherlands was established as a

protective reaction to the destruction caused by the 1953 North Sea Flood. This disaster

caused the death of 2500 people, the loss of nearly 40,000 properties, and the flooding of

10% of the arable farmland in the country. The Dutch government had began to modernize

its system before the disaster happened but it lacked the capital, both political and monetary

to proceed with its plan. Due to a universal cry for increased and improved protection the

Dutch government was able to launch its plan for modernization across the entire nation.

The modern Dutch Flood Prevention Shield has been designed to withstand a 1:10.000 year

storm, a standard which is constantly reevaluated to ensure optimal levels of protection.

This is ensured through the application of new technologies and techniques that improve

the FPS and in order to address the changing variables due to climate change and other

factors.

Figure 12 Figure 23

2 "Storm Surge Southern North Sea." Canon. Web. 01 May 2012. 3 "Dutch Dikes." - The Netherlands Photo. Web. 01 May 2012.

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The two images above show the modernization of dikes in the Netherlands during the 20th Century. The FPS that failed during the North Sea Flood (Right) has been modernized to ensure a greater level of protection (Left). Note the altitude and size of the dike, the elevated road, reservoir, and drainage channels.

The development of new construction practices has allowed the dike [levee] system

in place in the Netherlands to be able to stand the pressure of enormous volumes of water,

as well as the stress imposed by storms and major decay. This has been achieved through

the development of improved technologies and practices, such as the armoring the dikes,

the construction of a major canal drainage system, and the construction of emergency water

reservoirs.

The current Dutch Flood Protection Policy, “Give the Water Room,” attempts to

address the issues that may arise from a future increase in the height levels of the North Sea

and Dutch rivers.

Give the Water Room proposes:

1. The reclamation of coastal land to expand the buffer zones between inhabited

communities and the sea.

2. The rearrangement of existing dikes in order to expand the rivers banks increasing

the volume of water that waterways can hold without adding more pressure to the

barriers.

3. Increase the number and depth of overflow canals in order to better manage surging

levels and volume of water. Provide for a more expansive draining system for

floodwaters in the case of an eventual major or minor disaster.

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4. The creation of water storage locations [e.g. artificial reservoirs] towards which

high volumes of water may be moved in the eventuality of a flood or an emergency.

The “Give the Water Room” Policy combines infrastructural innovations in the face of

rising sea levels and increased storm patterns that the Netherlands today faces. Instead of

facing the dangers of flooding directly, this policy proposes a system of defenses by

allowing the water to be more free and not as constricted, and therefore, instead of facing a

direct onslaught; the system functions by allowing the water to flow more freely, resulting

in a decrease on the pressure that is being forced constantly on the FPS.

The Dutch Ministry of Infrastructure is in charge of the overall development and

structure of the Flood Protection System of the Netherlands, but even before its modern

inception in the 20th century, a devolved system of administration has existed in the

country: the Water Boards. In essence they are very similar to the structure of the former

Orleans Parish Levees Board, although designed for a smaller, more manageable area.

These boards are in charge of the day-to-day maintenance and supervision of their dikes

and polders [reclaimed land areas] and perform minor works on them if necessary. By

devolving certain authority and responsibility to a local administration the Dutch have

increased the efficiency with which they can handle the upkeep of their system, as well as

the response to any major or local development that may emerge.

The Netherlands shares many geographical similarities that allow it to be used as a

model comparison of what should be done in the City of New Orleans. A majority of the

Dutch territory lies at or below sea level; and the Rhine River passes through a large

portion of the country and is one of its main economical arteries just like the Mississippi,

both of whom if unrestrained would endanger and flood major populated areas. The

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Netherlands is located on the North Sea, which is constantly eroding the country’s land

area, much like what is happening in the Gulf of Mexico, to which the Dutch have

responded through their system of polders for reclamation of land. All in all, the

Netherlands provides the best example of what a nation, when faced with adversity, may do

when there is both a universal cry for change and the necessary political and economic

capital to achieve it.

Building CodesImplementation of

Embankment Protection

Natural Protection

Foundation of Stability Analyses

Implementation of Freeboard

Design

Land Use

X XPreservation of natural environments that provide protection such as wetlands and natural barriers due to erosion.

XAnalysis of the structural foundations of the dikes performed constantly in order to combat gradual sinking and erosion.

XAdditional construction provides greater margin of safety.

X

Levee Certification

Assessment Research and Development

Sustainability Training

XAll dikes in the Netherlands are public property and are certified by the National Ministry of Infrastructure and the Environment and the individual local wáter boards.

XConstant assessments are performed by the national Ministry of Infrastructure and the environment in coordination with the individual local water boards.

XPartnership with academic, and public and private enterprises allows for new technological development in the field of Flood and Water Management.

XNew practices and technologies implemented combine economic feasibility with environmental standards ensure an environmentally sustainable infrastructure.

XHigher education and employment standards, innovative training technique ensure competitive labor force in charge of the protection system and public safety.

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Program OversightPublic Involvement Periodic Assessment of

PerformanceContinuous Funding

XThrough locally elected water boards the people have a say in the expansion and maintenance of their Flood Protection System.

XQuinquennial assessments of the entire flood protection system and its capacity.Annual assessments of individual sections of the system.

XA continual funding is provided for the management of the system.

Risk CommunicationIndependent Review

CommiteeAwareness Campaign Emergency Management

XThe Gov’t maintains the issue of flood protection constantly in the minds of its citizens through public awareness campaings.

XCentralized Emergency Response. Benefitted from small territory and concentrated population.

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CALIFORNIA VALLEY FLOOD PROTECTIONAs a remedy to riverbeds, levees were built very close to the river channels to keep

water velocity high and thereby scour away the sediment.

By the turn of the 20th century, a large device called a sidedraft-clamshell dredge was

being used to remove material from riverbeds to increase the size of levee barriers.

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In 1917, Congress authorized the Sacramento Flood Control Project, which was

completed by the U.S. Army Corps of Engineers in 1960. "Project levees" built by the

Corps were designed to provide superior flood control protection. Once completed, the

general upkeep of project levees was turned over to local entities. There are more than

1,600 miles of State-federal project levees in the Central Valley, 385 miles of which are

located in the Delta.

California has used flood forecasting and flood operation management for about a

century. After a severe flood across Northern California in December 1955, The

Department of Water Resources established the Division of Flood Management was created

in November 1977.The Division of Flood Management, among several others, is carrying

out the work of the Department's Flood SAFE California Program which partners with

local, regional, state, tribal, and federal officials in creating sustainable, integrated flood

management and emergency response systems throughout California.

The State of California increased its preparation and the ability to protect against

heavy rainfall directly after Hurricane Katrina struck New Orleans. On February 24, 2006,

Governor Arnold Schwarzenegger allocated $500 million in state funding to assess the

levee system after heavy rainfall. Protecting Sacramento and the San Joaquin River Valleys

is critical to saving $47 billion in infrastructure. In addition, the State of California passed

two bond measures that would provide $4.9 billion for levee and other flood protection

repairs and improvements.

The California Department of Water Resources has repaired 300 levee sites using

state funds, with 100 sights deemed “critical.” Drill evaluations extracted soil samples of

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http://www.water.ca.gov/floodsafe/


the levee in 1,000 ft. intervals, and the samples underwent analysis in which factors as

moisture, density, soil grain size distribution, and shear strength.

To test those criteria, technical specialists measured by:

- analyzing existing levee historical data- mapping near-surface geology- conducting field explorations- performing engineering, stability and seepage analyses by electromagnetic surveys,

underwater bathymetric surveys, and light detection and ranging (LIDAR)- Topographic surveys using helicopters

Geomorphic drill testing in Central California

Cooperation between the California Central Valley Flood Protection Board and the Army

Corps of Engineers increases transparency and perpetuates good relations between the state

and federal government. Both institutions recognize the same standards of security and

have created a unified policy aimed at combating natural disasters in the Valley.

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RECOMMENDATIONS To ensure the best protection, the City of New Orleans must implement the

following recommendations:

- Develop standards to guarantee that the best engineering practices are implemented

and that the levees’ provide safety.

- Foundation stability analysis so the levees are built in cohesive materials, so levees

have a higher chance of resisting overtopping without breaching.

- A flood control structure should be built at the main entrance to Lake Pontchartrain,

protecting communities around Lake Pontchartrain up to Baton Rouge

- Establish pump stations to block any storm surge from the lake from entering the

canals.

- All levees need to be substantially raised by the implementation of freeboard

design.

- All levees should integrate armoring that protects levees from wave attack and

erosion.

- Avoid the use of the ineffective I-wall concrete floodwalls. Build “T-wall”

floodwalls, which are equipped to better resist overturning and lateral displacement.

These T-walls will need to be analyzed with regard to this potential failure.

- Incorporate Dutch-type floodgates and pile-supported barrier structures

- “Build a surge protection barrier system westward of the Mississippi river

- “The barrier needs to be elevated a given number of feet to provide additional

protection in the event of overtopping and reduce flood damage if rainfall flood

exceeds the capacity of the pumps” (Van Heerden, 31)

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- Building and restoring wetlands, to prevent overtopping, water degradation

(experienced in the Netherlands) and protect levees. By collaborating with the state

of Louisiana and non-governmental organizations, such as Environmental Defense

Fund, the City of New Orleans would be able to restore and develop some natural

buffers between the City and the sea in the lower delta of the Mississippi River.

- “The barrier levee and gates protect the built environment, the wetlands protect the

levees, and the barrier islands protect the wetlands” (Van Heerden, 34)

- Legislation to stop development in the wetlands and mandate retreat in high-risk

areas.

- Thomas Birkland explains that structural features of the American government alter

and slow down the policy process. As seen during Hurricane Katrina, there was no

efficient emergency response because there was confusion about who was

responsible and who had the authority. Hence, the federal, state and local

government needs to work together and delegate responsibilities, and thus

improving the system of accountability in case of an emergency.

- An external expert should certify the design; construction and implementation of the

hurricane and flood protection system are consistent with standards and address the

unknowns.

- The City of New Orleans should establish a committee to assess the current

integrity of the levee protection system. The committee would be in charge of three

main aspects of the revitalization of the levee system:

1. Use the Californian system to evaluate the standard of each levee built.

2. Proper allocation of funds and resources

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3. Meet every five years and set up a group of engineers and experts to inspect and

determine if any modifications are need to keep the levee system up-to-date and

at its best.

- “Storm surge numerical models must be used to fully investigate possible surge

conditions under a whole range of storm sizes, forward speeds, angles of approach”

(Van Heerden, 32) and thus, improve the levees where necessary.

- Communicate to the public the risks of living in such a vulnerable area, so they

understand that levees reduce but not eliminate the risks.

- Push Congress to pass a bill that guarantees that the flood and hurricane protection

system are funded at the federal level.

- Additionally, similar efforts should take place at the state and local governments to

create their own grant programs for levee rehabilitation

- Supported by the evidence given, the City of New Orleans should implement

similar policies used by the Dutch in their flood protection system. The Netherlands

has a defense to defend against a flood only said to happen once in 10,000 years.

New Orleans levee system is only designed to protect against a 100-year storm. By

collaborating with the state of Louisiana and non-governmental organizations, such

as Environmental Defense Fund, the City of New Orleans would be able to restore

and develop some natural buffers between the City and the sea in the lower delta of

the Mississippi River.

- Mandate citizens living the leveed areas to purchase a flood insurance to reduce the

economic losses from flooding.

- Education and awareness campaigns to communicate to individuals that levees do

not eliminate the risk from flooding.

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- Guarantee that all practices are environmentally friendly.

- Training programs to increase the level of expertise in those involved in the process

of design, construction, operation, maintenance and oversight.

The safety of the citizens must remain a top priority for the city. It has been realized that

some of this falls out of the jurisdiction of the city; however, if it remains a top priority in

the City and amongst its citizens, this problem will not fall by the wayside.

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APPENDIX:

Glossary of Standards

- Assessment: government agencies constantly inspect levees and provide technical assistance where necessary to implement levees consistent with standards.

- Awareness Campaigns: develop a comprehensive program of education and awareness to communicate the risk in leveed areas. Citizens in these areas need to understand the role of levees and know that while levees are designed to reduce risk, they do not eliminate it.

- Closure design: all openings have closure devices; closures are designed according to sound engineering practice and are a structural part of the levee during operation. (FEMA, 44 CFR 65.10)

- Continuous funding: develop a program to ensure that funding is available for research, rehabilitation, improvement or removal of deficient levee infrastructure and to maintain the necessary expertise and risk communication programs,

- Embankment protection: it is used to prevent erosion of levee embankment during the base flood. (FEMA, 44 CFR 65.10)

- Emergency Management: it includes but not limited to emergency plans, evacuation plans and designed routes for evacuation.

- Foundation stability analysis: evaluating expected seepage during base flood loading conditions, including flooding depth, duration, penetrations and other seepage and stability factors.

- Freeboard design: Engineers address uncertainties in levees’ design by adding freeboard to raise crown elevation beyond the minimum specified.

o Settlement analysis assessing potential freeboard loss due to settlement, showing that minimum freeboard will be maintained. (FEMA, 44 CFR 65.10)

- Independent Review Committee: a committee responsible to ensure that levees are operated and maintained in accordance with appropriate and protective standards by constantly inspecting levees.

- Land use: a plan for land use that establishes a buffer zone between levees and the populated area to minimize the risks to the population in case of flooding.

- Levee Certification: the design for all new levees and existing levees have to comply with the standards specified and must be certified by a professional engineer.

- Natural Protection: wetlands, marshes and barrier islands act as storm-buffering protection and protect the levees’ infrastructure too.

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- Periodical assessment of performance: develop programs focused on continual and periodic inspections.

- Public involvement: Citizens are aware of the protocols and procedures during an emergency and know the steps for protecting their families, homes and businesses from flooding.

o Projects need to increase the public involvement in levee safety programs. - Research and Development: Develop technology and engineering practices for

levee site investigation, design, construction, operation and maintenance. - Sustainability: develop measures that guarantee that the levee operations and

maintenance are environmentally friendly practices. - Training: training programs to increase the level of expertise and knowledge in all

aspects of levee safety to those involved in the design, maintenance and oversight of levees.

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WORKS CITED Cardno, Catherine A. "Hurricane Protection System Reviewed, Deemed Successful

during Hurricane Gustav." Civil Engineering (08857024) 79.8 (2009): 30-2. Print.

Eisler, Peter. "Panel to Urge National Safety Standards for Levees ; Federal Committee's Preliminary Findings show that no One really Knows if the Barriers could Withstand a Flood." Usa Today, sec. NEWS: 4A. Print. December 22 2008.

FEMA. "Requirements of 44 CFR Section 65.10: Mapping of Areas Protected by Levee Systems." FEMA Library. Apr. 2009. Web. 20 Apr. 2012.

Heerden, Ivor Ll van. "The Failure of the New Orleans Levee System Following Hurricane Katrina and the Pathway Forward." Public administration review 67., Special Issue on Administrative Failure in the Wake of Hurricane Katrina (2007): pp. 24-35. Print.

House, Gary W. "Actions for Change." Recommendations for a National Levee Safety Program. 7 Oct. 2008. Web. 26 Apr. 2012.

National Commitee on Levee Safety. "Recommendations for a National Levee Safety Program." Recommendations for a National Levee Safety Program. Web. 27 Apr. 2012.

Netherlands Ministry of Infrastructure and Environment. “Water”. Web. April 28 2012.

Reid, Robert L. "Louisiana Levee District Launches Local Hurricane Protection Plan." Civil Engineering (08857024) 80.6 (2010): 16-20. Print.

Shuster, Laurie A. "RISK ANALYSIS: ASCE Panel Finds Risk Level in New Orleans 'Unacceptable'." Civil Engineering (08857024) 78.6 (2008): 15-6. Print.

Sills, G. L., et al. "Overview of New Orleans Levee Failures: Lessons Learned and their Impact on National Levee Design and Assessment." Journal of Geotechnical & Geoenvironmental Engineering 134.5 (2008): 556-65. Print.

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