Introduction to the City of New Orleans - Assignment Example

Communicating Risk-Post Katrina: Summary and Answers Summary of “Communicating Risk-Post Katrina” by Pete Cali Introduction to theCity of New Orleans The city of New Orleans was founded along the bend of the Mississippi River in 1718. The map below shows the expansion of agricultural interests along the high ground afforded by the natural levees of the pre-Katrina New Orleans city of the year 1828. The flood protection levees indicated in the diagram below created a soup bowl effect that allowed the water to be drained out of the city. The 1849 maps below indicate the expansion of the city limits along the high ground and the destruction of the cypress swamp through the timber harvesting. This is believed to have been the cause of the breach of the natural levee along the Mississippi River that led to the Katrina flooding in New Orleans. The 1849 map indicates that despite the major breach on the levee, the city remained secure from flooding. The 1978 map below shows the impact of the growth population on the sypress swamp areas are more land was reclaimed to pave way for resettlement implying that the city was barely protected from any hurricane flooding. The encroachment and growth of the population behind the hurricane protection system indicates the level of confidence the people had in the engineering projects to protect them from floods. The damage caused by the Katrina The Katrina had devastating effects in the city of New Orleans. Firstly, ninety-five percent of homes in New Orleans East were flooded while 10,000 homes in the Greater New Orleans area were destroyed. Secondly, the Katrina destroyed vital infrastructure such as roads, sewerage, gas and water pumping stations, hospitals and public transportation. Thirdly, the Katrina destroyed approximately 160 miles of flood protection levees and floodwalls at the London Avenue Canal, the Inner Harbor Navigation Canal and the 17th Street Canal. What triggered the Katrina? According to Pete Cali, the Katrina caused 50 breaches in the hurricane protection system. Forty-six of these breaches were caused by overtopping that caused excessive scour at the floodwall base or levee toe and four were caused by floodwall failures due to water loads within the design conditions. Cali argues that these failures were imbedded in three engineering mistakes namely: insufficient levee height, the use of substandard soil in the construction of the levee and inadequate definition of possible failure mechanisms. Actions for Change Pete Cali recommends three actions for change in the engineering fraternity that would reduce the risks of future hurricanes and floods of the same or greater magnitude as the Katrina. These include: Effective and comprehensive design, construction, maintenance and update of the engineering system with participation of stakeholders to make it robust Effective communication of the risks and reliability of the hurricane protection system to the public, Corps of engineers and public involvement in risk reduction Increasing the reliability and commitment of the Corps of engineering to public service professionalism Conclusion Despite the devastating impact of the Katrina on the city of New Orleans, it is imperative to note that the heart of the City, especially the French Quarter, the Garden District and the Saint Charles Avenue were spared from severe damage. However, the damage can still be felt in the Ninth Ward and the New Orleans East whose water supply and sewerage system is yet to be repaired and the housing facilities are barely enough to accommodate half the pre-Katrina population. Due to the limitations in the tax revenue, the City of New Orleans depends significantly on the assistance of the federal government for reconstruction of its infrastructure. However, the recovery and survival of the city depends on its ability to protect itself from a similar flood in the future and to communicate effectively on the risks. This can only be achieved through effective implementations of comprehensive designs, effective public and stakeholder communication of the risks and reliability of engineering projects and maintenance of professionalism in managing future engineering projects. Questions and Answer What was the research on current engineering issues at the time of design in 1960s and after Katrinas damage? According to Pete Cali, considerable amount of research had been conducted at the time of the design of the floodwall in the 1960’s. There was a time-tested design procedure accepted by the engineering industry and well documented in the design manuals and Corps design guidance. The design procedure had also been researched and load tested under other soil conditions. Conservative analysis proved that the design could be replicated under foundation and load conditions of other similar projects. Conservative studies also indicated that the safety factors were acceptable. However, no observations regarding the floodwall failures had been reported in textbooks and design manuals. Immediately after the Katrina damage, the Interagency Performance Evaluation Team (IPET) conducted a comprehensive study on the causes of the breach. Other External Review panels who also conducted parallel investigations into the engineering breaches that resulted into the Katrina flood oversaw this study. The scientific data, findings and recommendations were then recorded. The findings were validated ten month later by the Corps of Engineers who admitted that there were several engineering flaws in the construction of the levee height, the soil material used in construction and definition of failure mechanism. Were any alternate solutions evaluated at the time of levee design [in the 1960s]? Available studies indicate that alternative solutions were not evaluated at the time of the design of the levee in the 1960’s leading to the devastating levee failures during the Katrina. According to the results of the forensic and scientific investigation conducted by the IPET study, the Great New Orleans Hurricane Protection system was poorly conceived due to its failure to evaluate available options exhaustively. Firstly, the initial metrological and oceanographic analysis provided by the US National Weather Service based on the 1959 standard project hurricane were found to be obsolete by the year 1972 during the construction of the first phase of the Hurricane Protection System. The problem with the 1959 standard project hurricane was that the maximum sustained wind speed had been overstated by 20%. The Corps of Engineers were in a position to surge estimates of the underestimation of the wind velocity using the steady-state analytical approach, which was as sensitive as the modern “SLOSH” (Sea Land and Overwash Surges from Hurricanes) or “ADCIRC” (ADvanced CIRCulation) approach. Based on this evaluation and analysis, the Corps of Engineers would be able to evaluate alternative design standards for minimum heights above the sea level for the construction of the levee and floodwall that would have been able to resist overtopping using a combination of standard project hurricane waves and surge (Heerden, 2007). Secondly, the Corps of engineers did not explore the options of using different soils other than weak near-surface soils of the Greater New Orleans. This was pure negligence since the Corps of engineers were well aware of the weakness of the soil following the testing of the failed early 1980s metropolitan New Orleans drainage canal floodwall levees. They would be able to explore available improvements in the design options had they conducted an effective analysis of the possible seepage of the soil and its effect on the stability of the levee and floodwall (Van Heerden et al., 2007). Explicitly describe how contemporary issues such as environmental, sustainability, globalization, etc., impacted the selected engineering solution of levees. Were design engineers required to consider these issues in the 1960’s? Contemporary environmental issues are fundamental in the selection and construction of engineering solution of levees. According to the Environment and Heritage Division, the major environmental issues include increased risk of flooding, disturbance of natural parks and aesthetics and production of dust and noise during the construction process. It is recommended that the proponent of an engineering project develop an Environmental Management Plan (EMP), which addresses these issues. Firstly, the project has to outline how it will manage noise and dust produced during the construction. Secondly, it should also provide a revegetation maintenance plan that would ensure stability of the levee during flooding. Lastly, the proposer should develop a landscape plan that explains how the loss of natural habitat and mature tree would be prevented during the levee construction (2000). The design engineers were expected to comply with these issues in the 1960’s (Van Heerden et al. 2007). Would you explain why thousands did not evacuate New Orleans when they knew that a direct hit from a Category 4 hurricane would flood the city? If you were advised by the Weather Service to evacuate your residence in Miami- Dade County, would you obey it? Why or why not? Thousands of people did not evacuate the New Orleans when they were directed to do so because of the assurance they had received from the department of the Hurricane Protection System. According to Van Heerden et al. (2007), the New Orleans residents were not informed of the fact that the hurricane protection system needs further improvement in order to attain the recommended one-in-100-year standard. Furthermore, Van Heerden et al. observe that the people of the New Orleans were blinded by the claims made by the New Orleans District that the system would be able to withstand higher amounts of hurricanes ranging from a one-in-200 to one-in-300-year, which did not have scientific basis (2007). Would you be willing to support the cost of rebuilding New Orleans after reading some facts about the damage from Katrina? I would be willing to support the initiatives being directed towards the meeting the costs of rebuilding the New Orleans city even after reading understanding the facts and conditions leading to the Katrina flooding. This is because I strongly agree with the ideas presented by Cali regarding the need for open and accurate communication. I am quite aware that flooding is inevitable and may occur even under strangest prevention measures, however public communications would indicate the readiness of the engineering community to embrace commitment, openness and responsibility in their profession. Involvement in the rebuilding process would also show our commitment to move forward from the consequences of the Katrina having learnt great lessons that would inform our future professional and individual decisions regarding engineering projects. What are the types of information used to determine the appropriate levee height? The Congress authorized the Corps of Engineers to create the Lake Pontchartrain and Vicinity Hurricane Protection Project in the year 1965. The standard Project Hurricane Parameters were selected based on the 1957 data from the National Weather Service. These included the central pressure of 25.7 inches of mercury, wind speed of 11o mph, Radius maximum winds of 30 miles and forward speed of 5-11 knots. The height of the levee is also determined from data gathered using the Saffir-Simpson scale which is used to classify the Standard Project hurricane. Information regarding the height of the levee is also generated from the general levee design standards of protection, freeboard, cross-section and stripping (Howard, 2002). Describe the failure mechanisms used to design the sheet pile I-floodwall. Is it possible to define all possible failure mechanisms? Why or Why not? The sheet pile I-floodwall was designed following the full-scale test conducted by the Corps in 1984 for the E-99 floodwall. The sheet pile I-floodwall was loaded with water in increments to the top of the wall, without wave load or overtopping condition. Early warning from the test indicated that the sheet pile wall behaved unlike the prediction from available theories. However, the E-99 test did not show any observed water filled cracks and the floodwall did not fail. According to Pete Cali, it was possible to define all the possible failure mechanisms while designing the sheet pile I-floodwall. The post-Katrina investigation by IPET revealed that forensic physical and numerical modeling could also be conducted on the failed floodwall, although this was never done. In addition to this, Cali notes that although there were no observable documentation of the floodwall failures in textbooks and design manual, it was possible to predict the failure using available modeling techniques. Apart from this, reviews from the internal reviewers, higher authorities’ reviews, A-E designers, local sponsor engineering reviewers and external reviewers would have evaluated and predicted the eventual failure mechanism. Is it possible to effectively communicate risk and reliability associated with cost to the people of New Orleans? Why or why not? According to Cali (2006), it is possible to communicate the risk and reliability associated with the costs to the people of New Orleans. He provides an example of one of the victims who refused to be rescued from the rooftop claiming that he wanted the responsible stakeholders to prevent the flood or provide him with accurate information regarding his risk level so that he could make informed decisions. The people of New Orleans are aware of the factor that flooding is inevitable and would be happy if provided with accurate and reliable information. Cali, however observes that the greatest challenge for engineers would be in coming out openly and communicating the inherent risks to the leaders, public and securing appropriations for funding engineering projects (2006). Are you afraid to communicate to the public that reliability of any building structure is lower than, say, 99.7% and that the probability of failure of a geotechnical structure is greater than 0.001? Would these values make the public happy? Why or why not? I am not afraid to communicate to the public relating to low reliability of any building structure and the existing risk probability of failure. These figures will not make the public happy because they will instill fear and lack of reliability in engineering projects. However, according to Cali, this is better than simply keeping quiet about the discrepancies in the engineering designs and repeating the same mistakes that led to the Katrina hurricane. However, Cali argues that effective communication to the public, Corps of engineers and other stakeholders about the dangers of living behind a hurricane protection system, which is not complete and highly risky, would enable them to be more alert, robust and respond immediately to emergency evacuation programs (Cali, 2006). Describe the formal procedure adopted by the Corps of Engineers to investigate the scientific and engineering issues involved in the failure of levees caused by Katrina wind and water forces. Immediately after the Katrina flood, Lieutenant General Carl A. Strock, P.E., Chief of Engineers, USACE ordered an investigation into the Katrina problem in order to provide credible, objective scientific and engineering answers regarding the several questions raised about the performance and operation of the Hurricane Protection System in the Southern parts of Louisiana and New Orleans. The objective of the IPET was to determine the lessons that could be learned from the engineering failures that resulted into the Katrina and to recommend ways for improving the Hurricane Protection System in future. Following a compressive study by the IPET, the Chief of Engineers requested the ASCE to form a review panel consisting of independent and external reviewers to offer reviews and comments regarding the investigation and report presented by the IPET. 14 experts from key engineering and scientific disciplines specializing in the hurricane protection system failure were brought together by ASCE to form the ASCE Hurricane Katrina External Review Panel. The main objective and scope of work of this panel of experts was to provide an objective, real-time and ongoing review into the findings presented in the IPET report regarding the performance of the hurricane protection system in New Orleans and its environments. The panel members visited the affected area, investigated the damage created and evaluated the information regarding the Katrina and its causes. They also summated active comments and recommendations to the IPET and reviewed the IPET report during all the stages of its development (Anderson et al., 2007). References Anderson, C.F., Jurjen, A.B., David, E.D., Billy, E., William, E., Robert, B.G., Thomas, L.J, ` David, K., Dennis, S.M., James, K.M., Peter, N., Clifford, A.P, George, T. & Robert, ` T.(2007).The New Orleans hurricane protection system: what went wrong and why: a ` report / by the American Society of Civil Engineers Hurricane Katrina External Review ` Panel. Virginia, Published by American Society of Civil Engineers. Cali, P. (2006). Communicating Risks- Post Katrina: How did we get into this mess and what do ` we do about it? Hal Hunt Memorial Lecture, Hurricane Protection Office Howard, R.J. (2002). Levee design, construction and maintenance. The State of Victoria, ` Department of Natural Resources and Environment. Environment and Heritage Division, Department of Lands, Planning and Environment (2000). ` Alice Springs-Eastside Levee Proposal: Environmental Assessment Report and ` Considerations. Retrieved on 12 April 2014 from ` http://www.ntepa.nt.gov.au/__data/assets/pdf_file/0018/15192/assessment.pdf Van Heerden, I.(2007). The failure of the New Orleans levee system following hurricane ` Katrina and the pathway forward. Public Administration Review, (December 2007 ` special issue):25-35 Van Heerden , I. L., Paul, G.K. , Hassan, M. , Radhey, S. , Billy, P. , Lou, C. , Art, T., Ahmet, ` B., Kate, S.& Ezra, B . (2007). The Failure of the New Orleans Levee System during ` Hurricane Katrina. Report prepared by Team Louisiana for the Louisiana Department of ` Transport and Development. Read More