Katrina was the latest in a series of wake up calls. For more than two centuries our nation has approached protection against nature's most ardent forces with paradoxical combination of long term apathy and short term reactionary zeal. We are thrust into action after the disaster that, in fact, we knew would eventually come, but could not quite accept as a reality in light of priorities more immediate and more likely. The question now is will we as a nation remain awake for just a short time or for the long term? And, can we deal with these issues in the context of the future rather than that of the past?
Much of what has been written since Katrina has focused on detail. Who was responsible, why did structures fail, what caused the massive flooding and losses? Attention has focused on responsibilities of individual agencies or the implications of specific events. And, emotions were expectedly high, searching for a tie between cause and effect. Too little attention has been paid to the bigger picture, perhaps a much more effective lens into the cause and effect relationships we seek.
Katrina almost mimicked a disaster response exercise that occurred roughly a year before the real thing. In fact, the flooding and losses from Katrina were less than estimated for Hurricane Pam, a hypothetical slow moving Category 3 storm tracking just to the west of New Orleans used for a July 2004 Hurricane Response Exercise. Katrina should not have been a surprise, but to many it was. As a nation we were caught taking a risk!
Katrina was a monster, generating the largest storm surge to hit North America. The surge, coupled with long period waves, overtopped and overwhelmed many of the levees. It also caused floodwalls to fail, some by overtopping and some because of inadequate design. Of 350 miles of levees and floodwalls, 168 miles sustained damage, 41 miles were severely damaged. There were 50 major breaches, 4 of which were because of design deficiencies. The remaining breaches were caused by forces that exceeded design criteria, but the lack of resilience significantly increased the damage and losses suffered. Without breaching, Katrina would still have created the worse flooding ever experienced in New Orleans. With breaching, Katrina created one of the worst natural disasters in the history of the nation.
What led to this situation is a long story with multiple paths that converged in New Orleans on 29 August, 2005. Unfortunately, the underlying forces that generated the Katrina disaster were working decades before the storm. There were three major forces at work, change, compromise and complacency, all leading to un-defined, un-responded and un-communicated risk.
The first force was change. Changes were occurring, in the nature of the storms threatening New Orleans, in the very nature and character of the system put in place to protect New Orleans and in the number of people and value of property being protected. Hurricanes have tended to become stronger with time, and the "Standard Project Hurricane" defined in 1965 as having up to a 1:300 annual chance of occurrence, in 2005 no longer equates to a 1:100 event. The jury is still out on Katrina, but in today's terms, she is likely to equal or exceed the original 1:300 level of protection authorized for New Orleans.
The system was in a constant state of construction with some areas completed, others partially in place and some still on the drawing boards. A variety of federal programs and local management jurisdictions led at times to a variety of structures. The incomplete areas and the transitions proved to be least capable of providing protection. The system was also under a constant state of subsidence, in some locations at a rate of one foot per decade. Sinking structures and systematic errors in interpreting the local datum causing structures to be built lower than intended, resulted in some structures being 2 to 3 feet below their authorized elevations by the time Katrina struck. In some cases it was of little significance, in others it markedly reduced protection and increased vulnerability.
There was significant change in the demographics of the region. As more people and property occupied former marsh lands, the consequences of flooding increased dramatically. A full 78 percent of the property damage from Katrina was suffered by residential areas, many occupying the lowest elevations. Only eight of thirty seven neighborhoods were not flooded, creating a massive disruption to the social and cultural fabric of the area and significantly impeding recovery. Seventy five percent of the fatalities were individuals over the age of 60 and those individuals included many who were infirmed, disabled or poor. The people who were less likely to be able to care for themselves or self-evacuate were clearly the more vulnerable to the flooding.
There was also change in the state of knowledge. The information on the hurricane intensities was already mentioned. Information was also emerging about the failure mechanism that ultimately caused four of the floodwall failures, ironically about the same time as they were being designed. Yet the designs did not account for this mechanism and no actions were taken to reconsider the integrity of the structures. The new information concerning the designs was simply not available to the right people, nor perhaps did the right people have the capability to effect significant change in the structures already constructed or under construction. In the case of subsidence and errors in datum interpretation, as well as the hurricane hazard, the decisions to not take action were deliberate decisions. This was perhaps because of the ponderous decision making system that challenged with a major change in mid-project, could in all likelihood have delayed construction of any protection.
All of these changes, an increasing hazard, a system that was not a system and increasing consequences of flooding, amounted to incremental increases in risk. The inability to bring new knowledge to bear to adapt the hurricane protection system to the new understanding of the vulnerability of the system sustained that risk.
The second force was compromise. The original plan for protecting New Orleans was focused on life safety, not economics. It was a systems approach dimensioned to deal with the "most severe storm likely" for the region. The original plan had protection in depth, and represented a systems approach. What was put in place, the result of many incremental compromises to deal with competing priorities, was significantly less. Gone was any semblance of protection in depth and in its place was a single line of defense, in places clearly marginal for what was to come. The levee - floodwall system along portions of the drainage canals were limited by real estate right of way. Their designs, I-wall structures combined with relatively narrow levees, reflected that constraint and resulted in designs not conservative enough to deal with the unknown of the new failure mechanism they experienced.
Some extensive sections of levee were constructed using hydraulic fill, capped with clay. While these levees were cheaper to construct, and performed adequately for smaller storms, they were not equal to Katrina. As such, the levees were not designed to withstand overtopping, nor were many of the floodwalls. When water exceeded their elevations, they were effectively disposable and all bets were off. Ironically, for the most part, they performed exactly as designed. Cost was likely one of the major drivers of compromise, also driving out incorporation of resilience and redundancy.
One of the major compromises was the fact that when Katrina hit, the hurricane protection system authorized in 1965 had yet another decade of construction remaining. After 40 years major sections remained incomplete. Fortunately, many of the least complete sections were on the west bank where Katrina had much less impact. The funding was not available to complete the system in a timely manner, an indication of the lack of national will to deal effectively with this type of hazard. This also amounted to incremental increases in risk, unaccounted for and unquantified.
The third force was complacency. New Orleans was last flooded significantly by Hurricane Betsy in 1965, the stimulus for the current hurricane protection system. In forty years there had been large storms like Camille and close calls like Andrew but no catastrophes. With no floods and a protection system under way, there was a false sense of at least guarded security. Development was enabled, more and more in the areas of lowest elevation and highest vulnerability to flooding. Unfortunately, many of the poorest neighborhoods were located in the lowest, most flood prone areas. As a nation we are usually focused on the short term, and complacency with respect to infrequent hazards, is too often a part of our culture. We have been satisfied to use economics as a measure of justification for hurricane flood damage reduction. We are satisfied with achieving a 1:100 level of protection, even when protection of life is the real objective. Others such as the Dutch and Japanese seek 1:10,000. Life cycle benefits are only obvious and essential when you are caught without them. We now know that New Orleans likely had protection levels below 1:100 in August of 2005, and Katrina was far superior to what was there.
We lack the national will to deal with long term hazards with long term strategies and investments. The same short term emphasis pervades local, state and national decisions. It is also easy to falsely assume that the impact of events like hurricanes are primarily local. The consequence analysis for Katrina looked at regional and national impacts, demonstrating that this is not true. The economic cost to the nation will likely far exceed the local losses. It is easy to point to the political process and question why it is oriented to the budget and election cycles rather than the "life" cycle more appropriate for infrastructure and natural hazards. The fact is, we the public are still the driver of the political decision process. If we want to change this situation, we need to change what we are telling our representatives, when we vote and proactively in any forum available. In the long run, short term policies and investments are costing citizens and the nation an enormous tax. We will be recovering from Katrina for a long time, in New Orleans and nationally and the cost will be staggering compared to the investments that would have dramatically reduced the losses from this single event.
Alvin and Heidi Toffler's recent book, Revolutionary Wealth, highlights three "deep fundamentals" that underlie many of the challenges we face in society. These fundamentals of time, space and knowledge nicely capture the major issues discussed here and the challenges faced by communities, regions and the nation concerning hurricane and natural hazard protection. Time represents the dynamics of the hazard, the system, the consequences and the knowledge related to the levels of risk that existed. As a nation we do not anticipate or manage change well, too often resorting to the convenience of assuming a static or status quo world. Space represents the fact that local, state, regional and national (federal) interests were and continue to be involved in the decision making and investments for New Orleans hurricane protection. These interests and perspectives are often desynchronized and in conflict, resulting in compromise that inadvertently increases risk.
Space also relates to the consequences that were not just local but nationwide. Just as with globalization, processes that are influenced differently at different scales are complex and harder to understand. As a nation, we do not deal well with issues that have multiple scales and complex interdependencies. They do not fit into the taxonomy by which our legacy economic, legal, social and political processes work, inherently increasing risk.
Knowledge represents the increasing body of knowledge on all aspects of hurricane protection. Knowledge of climate dynamics exposes us to the fact that the future hazard can be significantly different from that of the past. Knowledge of the processes of storm surge and waves gives us the capability to more accurately understand hazards and design damage reduction measures that can be adaptive to change as well as effective from a systems perspective. This same knowledge can materially improve forecasting of who and what might be vulnerable from an impending storm, dramatically increasing the focus and effectiveness of emergency response activities.
New capabilities such as risk and reliability assessment will allow decision makers (at all levels) to better understand the short and long term costs (lives, environment, economics and social) of alternative approaches to reducing risk. These same methods also provide a new level of understanding of the sources of risk, enabling a more focused approach to risk reduction from a life cycle and systems perspective, not to mention the ability to better inform the public of the level of risk they are assuming given their locale. While all this new knowledge represents a significant opportunity to reduce risk, it is of little value if it is not put to use.
The new knowledge signifies that some of the previous knowledge and method used for hurricane protection are now obsolete. As a nation we are not very effective in jettisoning the old, even after we have recognized and entertained the new. Maintaining legacy information and methods, (for example, outdated design guidance or hazard definitions) is tantamount to sustaining risk.
In short, Katrina caught us with our risk up and our guard down. To address these issues, we must first think big picture and long term. Reform of individual components or practices of the overall process will not solve the problem. It will require a systematic look at how the entire organism behaves, what drives it and the interdependencies in the context of time, space and knowledge. This will take some time and careful thought by a diverse group representing many factions and stakeholders. How long will we remain awake?