10 Years after Katrina: Lessons Learned, Lessons to Learn
As the nation marks the 10-year anniversary of Hurricane Katrina, we reflect on the catastrophic impact the storm had on New Orleans and the entire Gulf Coast region.
Katrina remains one of the deadliest and costliest hurricanes in U.S. history, with more than 1,800 lives lost and damages estimated at over $100 billion. When the levees failed, about 80 percent of New Orleans flooded. More than 1 million people across the Gulf Coast were forced to leave their homes — many never returned.
In the years since, the region has served as a laboratory for researchers from the Georgia Institute of Technology who have traveled to New Orleans and other locations to study the effects of the disaster. Their work has helped determine what went wrong; how best to rebuild the region; and how to help the nation prepare for future calamities.
“The country as a whole is really not prepared for disasters of this sort,” said Georgia Tech President Emeritus G. Wayne Clough, who led the Institute from 1994 to 2008.
As a young civil engineer, Clough worked with the Mississippi River Commission, which had governance of flood control systems down into New Orleans. In the days following Katrina, Clough was selected to lead a National Research Council team that formed at the request of the Department of Defense to assess what went wrong and how best to respond.
He was among the first group of experts to arrive post-Katrina. The New Orleans he had known was a vibrant, active, and joyous city. This was different. No other flights landed at the airport. Few cars drove on the roads. Restaurants, hotels, and streets were empty.
“It was a very strange feeling to go into a modern American city and see it stripped bare, if you will, of its essence and knowing you want to bring it back,” he said.
The powerful storm, combined with fatal engineering flaws, had caused the flooding. The old system protecting the city had little resilience, so when one part failed, others followed until it all collapsed, Clough said.
The new levees and floodwalls have been designed to withstand a 100-year storm – one with a 1 percent chance of occurring in any year. This system is far more robust and resilient than the previous one, but it still can be overtopped by a storm that is big enough or follows a path that brings Katrina-like storm surges, Clough said.
Because there is a chance New Orleans will flood again, Clough and his committee recommended that areas most at-risk for flooding not be redeveloped. Despite this advice, people have been allowed to rebuild across the city.
This makes it all the more important to keep viable and up-to-date evacuation plans at hand, Clough said.
Unfortunately, Katrina didn’t serve as a warning to areas beyond the Gulf Coast. New Orleans was considered unique because the city was built below sea level; many expected it to struggle during a hurricane.
Opinions changed after Hurricane Sandy in 2012, however.
“Sandy was a wake-up call that this could happen anywhere,” Clough said.
Still, too many cities operate on short-term memory, and if they haven’t recently felt the impact of a disaster they’re unlikely to prepare, said Pinar Keskinocak, co-director of the Georgia Tech Center for Health & Humanitarian Systems.
The center’s quantitative approach for disaster preparedness uses scientific models to demonstrate the trade-offs between costs and outcomes, said Julie Swann, co-director of the center. The center offers professional education classes for government, industry, and non-governmental organizations on how to improve decisions made during disaster preparedness and disaster response.
Cities need to invest in stockpiles of food and water and think about evacuation plans and transportation in and out of an area, Keskinocak said.
They must consider debris removal issues, such as how to reopen blocked or damaged roads and in which order to open them, she added. Debris must be cleared so relief supplies can be delivered and it must be properly disposed of to avoid health and environmental threats. The solid waste created during Katrina would have taken 100 million years to form under non-disaster conditions. Clean-up efforts were about 25 percent of the total disaster costs.
Communities must also pay special attention to at-risk populations. Nearly half of the Katrina victims from Louisiana were over the age of 74.
To help leaders determine how to invest their resources and time, Swann advises communities to consider an equation related to disaster need: the magnitude of the disaster times the vulnerability of the population divided by the capacity to respond.
“With disasters you’re investing for what might happen,” Swann said.
Hurricane Katrina also showed the need to provide health and safety training for disaster recovery workers.
Paul Schlumper, a research engineer with the Georgia Tech Research Institute, conducted training sessions and developed communication materials to address the occupational and safety health hazards that disaster recovery workers and others could encounter.
He and his team trained more than 7,600 people in the Biloxi, Mobile, and Gulfport areas through a one-year Susan Harwood Training Grant awarded by the U.S. Department of Labor’s Occupational Safety and Health Administration.
The training stemmed from the lessons of the Sept. 11 attacks, when rescue and response workers were exposed to safety and health hazards. When Katrina hit, officials realized an organized occupational response was needed, Schlumper said.
“There is a mindset that we want to rush in and respond when something happens, but you have to also pay attention to your own safety and health,” he said.
There were no classrooms or centers in the Gulf area where Schlumper and his team could hold training classes, so they held sessions in tents and spoke from the tailgates of pickup trucks.
They reviewed information about the proper protective equipment and possible dangers associated with construction, demolition, and removing debris — dangers such as falling, mold, and electrical hazards.
The challenge is preparing for events that happen infrequently but have the potential to bring devastating consequences that last for years. Findings from the research conducted after Hurricane Katrina should convince government officials and communities to invest in mitigation, said Reggie DesRoches, the Karen and John Huff School Chair of Georgia Tech’s School of Civil and Environmental Engineering.
He and a team supported by the American Society of Civil Engineers surveyed the damage inflicted on about 25 bridges in the Gulf Coast region.
The big difference between the bridges that sustained damage and those that did not was the connection between the deck and supporting piers, he said. Bridges that were either rigidly connected or had lateral restraints performed well, while those that did not failed.
Also, bridges that had vents in the bents, which are used to support beams and girders, performed better because the vents reduced the uplift forces from the water, DesRoches said.
DesRoches also studied the storm’s impact on the Port of New Orleans through a National Science Foundation grant.
While physical damage to the port was limited, operations were impacted, he said.
Because communication systems were down, workers could not contact the port to know if they were needed. Employees couldn’t get to work because of extensive damage in the surrounding areas. Also, there were not enough provisions for backup power.
To prevent this in the future, back-up systems for communication are needed. Also, critical equipment should be positioned above flooding levels and officials should stockpile emergency materials, such as fuel.
“The research community can play a major role in really helping officials understand what mitigation might do in terms of outcome from a disaster,” DesRoches said. “We have to change the culture and mindset.”
One change will be in evidence when hurricane warnings go out this season: Warnings will now include storm surge forecasts along with wind velocity, said Hermann Fritz, an associate professor in civil and environmental engineering, who studied the effects of storm surge post-Katrina through a grant from the National Science Foundation.
The Saffir-Simpson hurricane wind scale classifies hurricanes into five categories based on the intensities of the sustained winds. But wind only tells part of the story. Storm surges and waves during Katrina led to extreme coastal flooding. Fritz measured high water marks exceeding 30 feet in between Waveland and Biloxi.
His team, which included undergraduate and graduate students, surveyed the coastlines of Alabama, Florida, Louisiana, and Mississippi and found that the high water marks for Katrina surpassed those from Camille.
When Hurricane Katrina made landfall in New Orleans, it weakened to a Category 3 storm. Some residents chose not to evacuate because their homes had survived Hurricane Camille in 1969, which was a Category 5 storm. Unfortunately, Fritz observed, buildings that were designed to be hurricane-proof withstood the wind velocity but were destroyed by the storm surge. Even churches and other buildings designed as hurricane evacuation shelters were washed out by the storm surge, despite their wind-resistant design.
Not a single window was blown out at the high-rise Beau Rivage Casino in Biloxi, but the casino floors where the croupiers played roulette were gutted and washed away.
“Katrina was really the one that shifted the focus back to storm surge,” Fritz said, adding that the destructive potential of rising water was further emphasized by Hurricane Ike in 2008 and Hurricane Sandy in 2012.
Clough said a deeper understanding of climate change will affect how cities prepare for natural disasters. Climate change is exacerbating sea level rise, which increases the frequency and severity of coastal flooding.
This increase in sea level will take time, but in the meantime, Clough said, engineers and others designing systems to protect against hurricanes must factor this into the design.
Engineers, he said, can provide the data and research to get the entire nation thinking about disaster preparedness. The country came together to build the interstate highway system, and a similar approach is needed now, he added.
“We need to have a national dialogue so we can think creatively about these issues,” Clough said. “We need to think of this as a common problem facing the country.”