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Beyond Katrina: Lessons Learned | 8.26.2010

Five years ago, New Orleans was ground zero in one of the worst natural disasters in U.S. history. Three years later - almost to the day - the city survived another major hurricane with barely a scratch. What happened to make the outcomes of Hurricane Gustav so much different from Katrina? It was the culminations of lessons learned, not only from Katrina but from a series of events dating back a decade.

It is true that government officials learned from Katrina, but Katrina was just one milestone along the way toward making New Orleans safer. In fact, New Orleans, the State of Louisiana, and the Gulf Coast region had already learned a great deal prior to Katrina. Those lessons, in addition to the lessons learned from Katrina made for arguably the most efficient and orderly evacuation of a large urban area ever conducted. The progression of events highlights the trust officials placed in improved forecasting, the role of planning, and the extent of learning from prior experience.

Georges, Pam and Ivan

Few will recall these storms in the same way they recall Katrina, but each taught important lessons that prepared the city for future challenges. The lessons began back in 1998 with Hurricane Georges. Georges seemed to take dead aim on New Orleans before veering sharply to the east, making landfall in Biloxi, Mississippi. Although New Orleans was spared, it highlighted how ill-prepared they were for a major hurricane. Evacuation was uncoordinated and chaotic. Each parish had its own separate response plan. Some parishes called for mandatory evacuations while others did not. Some opened shelters while others did not. The timing of evacuations was not coordinated between parishes, and as a result roadways became clogged and those most vulnerable had great difficulty getting out of harms way.

New Orleans was again put to the test by Hurricane Pam in 2004. Although Pam was only a simulation and not a real hurricane, it revealed further weaknesses in evacuation strategies. In the scenario, it was assumed that 65% of the metropolitan area would evacuate, leaving 600,000 people behind to ride out the storm. Water from the overtopped levees combined with excessive rainfall overwhelmed the city’s drainage pumps, knocking out 80% of the pumps and leaving the city covered in water for more than a month. The scenario from Pam forced planners to confront tough questions. Participants had to identify specifically where they would obtain needed supplies, such as specific locations or suppliers of generators and how they would get them to the city.

Despite its level of detail, the exercise did not address longer-term issues, including temporary housing, relocation of displaced people, post-event security, reentry to the city by returning residents, and FEMA’s promised stockpile of provisions - all issues that would resurface with Katrina.

Just months after the Hurricane Pam exercise, Hurricane Ivan seemed to have New Orleans in its sights as it reached Category 5 intensity with sustained winds of 170 miles per hour as it tracked across the Caribbean. Like Georges, it made a sharp right turn before landfall and weakened, coming ashore at Gulf Shores, Alabama with 120 mph winds. Unlike Georges, however, Louisiana officials had vastly improved coordination of its state and parish evacuation plans. Yet like its predecessors, Ivan too revealed some weaknesses. As is now common practice in mass evacuations, the inbound lanes of major highways were turned outbound in a
process known as contraflow. This doubled the capacity of Louisiana’s highways to move people away from the coast. However, Louisiana officials failed to coordinate with Mississippi officials, who did not implement contraflow, causing a bottleneck along I-59 as people attempted to leave New Orleans.

Katrina comes ashore

While Katrina is well known for being among the worst U.S. disasters, there is an often untold story of the success of the evacuation. Learning from Georges, Pam and Ivan, over one million people from the New Orleans metropolitan area were evacuated within 36 hours, representing more than 80% of the region’s population and far exceeding the projections from the Hurricane Pam exercise. Coordination of evacuations between neighboring states improved traffic flow, even though more people across a much larger area of coastline evacuated.

The failure of Katrina lay in the unresolved issues from Hurricane Pam. Those who were not able to evacuate by their own means relied on services that were unavailable. Rental cars, buses and ambulances were in short supply and many public transportation systems were shut down well in advance of the storm. Damage from the storm severed transportation arteries going into and out of New Orleans, leaving hundreds of thousands stranded. Local resources were in short supply and federal materials failed to materialize as promised.

Gustav: A different tale

While Katrina may have been “the perfect storm”, Gustav was perhaps the perfectly-forecasted storm, at least in its track. From almost the moment it formed in August 2008, it was clear that Gustav was headed towards Louisiana. Two days before landfall, Mayor Nagin urged residents to “get your butts out of New Orleans.” Nearly two million residents along the Gulf Coast followed this advice, the largest evacuation of the U.S. coastline in history. Although Hurricane Gustav weakened before landfall, there was still substantial risk of flooding and levee breaches that kept the city on edge.

Louisiana officials became concerned about Gustav on August 25, while it was still a tropical storm in the Caribbean, 7 days before landfall. Expectations of rapid intensification in the Gulf of Mexico led to early preparations. Graduation for Louisiana’s newest class of state police officers was moved up three days so that extra manpower would be available. Local officials prepared for the worst-case scenario and shelters in surrounding states were contacted to move those unable to evacuate by their own means. Assisted evacuations began four days ahead of projected landfall and contracts were exercised to obtain as many as 700 buses - all of this while Gustav was still a tropical storm.

Three days before landfall, as Gustav intensified to Category 4 as was forecasted, Mayor Nagin issued a mandatory evacuation for New Orleans, saying that staying would be “one of the biggest mistakes you could make in your life.” Even before the mandatory evacuation order had been issued, an estimated 1 million people had already left. By the time Gustav arrived, 95% of the city’s population had evacuated. The American Red Cross, Louisiana Homeland Security and police were on standby, along with 300 National Guard soldiers in Baton Rouge and another 200 by air awaiting orders with another 7,000 National Guard solders deployed statewide. Officials were determined to avoid another Katrina.

More lessons to learn

While Gustav proved that officials learned from the past, there remain unresolved issues. Those who stay behind during evacuations include wanted felons and illegal immigrants, who would rather take their chances with the storm than possibly be captured at a shelter. While hurricane track forecasts have improved tremendously over the past decade, forecasting hurricane intensity at landfall is still a challenge. Related impacts of storm surge are another forecast challenge, making it difficult for officials to precisely target areas where evacuation is needed.

However, what Hurricane Gustav proved was that it is possible to evacuate large population areas along our coastlines, including those who are not capable of evacuating by themselves. Coordination between Louisiana, its neighbors, and the federal government moved those in need to shelters far away from New Orleans and then returned them safely within a matter of days. Louisiana officials deserve a great deal of credit for the seriousness with which they took the situation, at the first indication of a threat, keeping them ahead of events. Learning from the past led to a remarkable success story.

For more information, please read Lessons Learned (presented at the 2009 American Meteorological Society Conference).

And for further information, contact:

Mark Shafer
Oklahoma Climatological Survey/Southern Climate Impacts Planning Program
University of Oklahoma
405-325-2541
mshafer@mesonet.org

Barry Keim
Louisiana Office of State Climatology/Southern Climate Impacts Planning Program
Louisiana State University
225-578-6170
keim@lsu.edu

Gina Eosco
University of Kentucky
859-257-7805
eosco@ametsoc.org