Impacts of a Landfalling Tropical System
on Post-Katrina Southeast Louisiana


Katrina Takes Aim. This was the front page headline of the New Orleans Times-Picayune newspaper the day before Hurricane Katrina hit the Gulf Coast. This was the storm that everyone has feared. Katrina slammed into the Gulf Coast leaving catastrophic destruction in her wake. Southeast Louisiana was forever changed on that day. The area suffered damage that was weather related and due to man-made failures. Could another landfalling tropical system have the same consequences?

The 2005 Atlantic hurricane season saw twenty-five named storms. Tropical Depression twelve developed into Tropical Storm Katrina and then became the now infamous Hurricane Katrina. Hurricane Katrina was one of three Category 5 storms during the extremely busy 2005 Atlantic hurricane season. After hitting Florida as a Category 1, Katrina crossed the Gulf of Mexico. She traveled west and eventually turned to the northwest following a mid-level ridge moving out of Texas. Warm sea surface temperatures and an upper level anticyclone over the Gulf of Mexico allowed Katrina rapidly intensify. She quickly became a Category 5 storm. Katrina made a second landfall on the Gulf Coast on Monday, August 29, 2005 as a Category 3 near Buras, Louisiana. The eye of Katrina passed just to the east of downtown New Orleans. The storm made a third landfall near the Louisiana/Mississippi border still as a Category 3.

Katrina caused unbelievable damage to southeast Louisiana. The National Weather Service out of Slidell, Louisiana issued a bulletin the day before Katrina made her Gulf Coast landfall stating that Katrina's intensity would rival that of 1969's Category 5 Hurricane Camille. It also stated that most of the area in southeast Louisiana would be uninhabitable for weeks. This became a reality when high winds, heavy rainfall, and storm surge caused extensive flooding in the area. It is estimated that eighty to eighty-five percent of the city of New Orleans alone was under water due to the effects of Katrina (van Heerden, 109). This is number does not include flooding in the southern low-lying coastal parishes and the parishes on the northshore of Lake Pontchartrain. Many of these areas were once again flooded when Hurricane Rita made landfall near the Louisiana/Texas border in late September of 2005. Katrina is not the first hurricane to cause massive flooding in the New Orleans area. Hurricane Betsy in September of 1965 dumped heavy rains on the area as she passed to the southwest of the area. Betsy's storm surge caused the water of Lake Pontchartrain to overtop the levee system. Flooding due to Hurricane Betsy's storm surge caused Congress to implement the Flood Control Act of 1965. This meant that the U.S. Army Corp of Engineers had to build levees to protect the city of New Orleans from flooding catastrophically again. The Corps defining factors for the strength of the levees is that they must withstand a fast-moving Category 3 storm (van Heerden, 205). Unfortunately, the levees did not withstand this. The levee system around the New Orleans area was compromised during Katrina. Most of these levees are earthen levees. During Katrina the levees were not overtopped, they failed structurally. This caused numerous breaches around the area. This man-made failure led to the extensive flooding of the New Orleans metro area. The flooding on the northshore of Lake Pontchartrain was not due to levee failures. This flooding was purely due to Katrina's storm surge pushing into these parishes. The southern coastal parishes were also flooded due to storm surge from the Gulf of Mexico. Most parishes in southeast Louisiana suffered considerable wind damage. There was extensive property damage and property loss due to the winds and flooding. Thousands of people lost their lives.

In southeast Louisiana today there are many more factors that need to be taken into account when determining the impact that a land falling tropical system will have on the area. Katrina has immensely changed the dynamic of the area. Safety is now a major issue. The area is low lying and surrounded the waters of Lake Pontchartrain, Lake Maurepas, the Gulf of Mexico, the Mississippi River, and numerous canals and other smaller rivers and lakes. New Orleans is below sea-level and this is one fact that will not change. It is essentially a giant bowl. Once water gets into the city, the only way to get it out is by pumping it out. According to The Times-Picayune newspaper out of New Orleans, there are "475 miles of levees, locks, seawalls, and floodgates averaging 16 feet high" surrounding the New Orleans metro area (Washing Away, Day 1). Will these levees hold during the next storm? Are the repairs that were made to the levee breaches going to stay intact? Louisiana State University Engineering professor Joseph Suhayda determined that the city of New Orleans has four times the risk of flooding from a hurricane than from river flooding (Washing Away, Day 1). Will levees farther to the west of New Orleans the have been stable up to this point be able to hold up to another landfalling storm?

The population of the area is not yet back to post-Katrina numbers, but it is steadily increasing as many residents are making their way back home. If this type of flooding was to happen again, will as many people be willing to come back? Many families are still living in FEMA trailers as they continue to rebuild. Storm debris is still being cleaned up in some communities. Along with the storm debris comes a massive amount of debris from new construction. Winds from a severe thunderstorm or a tropical system could cause these items to become dangerous and possibly deadly. There are still many buildings in the area that are in poor condition and could become dangerous in windy conditions.

Southeast Louisiana is continuing to sink while sea levels continue to rise. The barrier islands that lie off of the Louisiana coast, as well as, inland marshes were heavily damaged during Hurricane Katrina. Many barrier islands are now basically non-existent due to Katrina's storm surge. These islands served as a storm surge buffer for Louisiana and Mississippi. Without these islands, wave action from the Gulf of Mexico is creeping further inland. The lack of the barrier islands during the next tropical system will allow for a higher storm surge and this surge will be able to push farther inland than it generally would. This creates a new potential for flooding in areas of southeast Louisiana that would not normally do so. This also means that more land will be lost into the Gulf of Mexico allowing the coastline of Louisiana to recede further inland. Damage from storm surge could dramatically increase from a storm much smaller than Katrina.

The Federal Emergency Management Agency (FEMA) held a storm scenario exercise with a fictional storm called Hurricane Pam. In the scenario, Hurricane Pam had "sustained winds of 120 mph, up to 20 inches of rain in parts of southeast Louisiana, and storm surge that topped levees in the New Orleans area" (FEMA, 2004). This exercise was held in July 2004, just over one year before Katrina hit the Gulf Coast. The exercise had action plans for debris removal, shelters, and search and rescue. This exercise was to serve as a way for city officials, state officials, federal officials and FEMA to prepare for future disasters. A second Hurricane Pam exercise that was supposed to take place in the summer of 2005 was cancelled. If most city, state, and federal officials were not prepared after this exercise, how can the citizens of southeast Louisiana be sure that they will be prepared the next time?

The National Oceanic and Atmospheric Administration (NOAA), in conjunction with the Shell Oil Company, is in the process of placing sensors on several oil platforms in the Gulf of Mexico. These new sensors will use more a advanced technology that will allow for a closer tracking of meteorological data during hurricane season (The Times-Picayune, 2008). This will provide more up to date information on sea surface temperatures, speed and direction of currents, and storm information from the Gulf of Mexico.

There are more questions than there are answers to how another landfalling tropical system would impact post-Katrina southeast Louisiana. It is only a matter of time before southeast Louisiana takes a direct hit from another major hurricane. Unfortunately, a direct hit is bound to happen eventually. Katrina was a Category 3 when she hit, not the Category 5 monster that was expected. Will the area be able to withstand the next challenge that mother nature has to throw at it? What impacts will it have? Only time will tell.

Works Cited:

Van Heerden, Ivor and Mike Bryan. The Storm-What Went Wrong and Why During
Hurricane Katrina-The Inside Story From One Louisiana Scientist.
New York: Penguin Books, (2006).

The Times-Picayune. Washing Away. (2002)

Quillen, Kimberly. Sensors Will Collect Storm Data. The Times-Picayune.
February 2008; p. A-19.

Federal Emergency Management Agency. Hurricane Pam Exercise Concludes. (2004)