Hurricane preparedness in New Orleans


Hurricane preparedness in New Orleans has been an issue since the city's early settlement because of its location.
New Orleans was built on a marsh. Unlike the first two centuries of its existence, today a little under half of the modern city sits below sea level. The city is surrounded by the Mississippi River, Lake Pontchartrain to the north, and Lake Borgne on the east.
The earliest-settled parts of New Orleans and surrounding communities are above sea level. However, flooding was long a threat, from the periodic high waters of the Mississippi and from more occasional severe tropical storms which pushed the waters of Lake Pontchartrain into settled areas. Construction of the levees along the River began soon after the city was founded, and more extensive river levees were built as the city grew. These earthen barriers were erected to prevent damage caused by seasonal Mississippi River flooding. The Lake Pontchartrain shore was mostly undeveloped swamp, and only small levees were built there in the 19th century.

Colonial era

Awareness of the city's vulnerability to hurricanes dates back to the early Colonial era. A major hurricane hit the city in September 1722, leveling many of the buildings in the young city.
1794 was perhaps as dreadful a year as the city of New Orleans ever experienced, as it suffered two hurricanes in addition to a major fire.

19th century hurricanes

The 19th century saw powerful hurricanes such as the 1856 Last Island Hurricane and the 1893 Chenière Caminada hurricane. Both, both of which were devastating.
The Last Island Hurricane, the first of two major hurricanes in the 1856 Atlantic hurricane season. The storm first made landfall at Last Island, located southwest of New Orleans on the Gulf of Mexico, destroyed nearly every building on the island, and killed more than 200 people of the 400 people on the island. The island was "left void of vegetation" and fragmented into smaller islands that have remained uninhabited ever since. New Orleans received of rain during the storm.
The Chenière Caminada Hurricane of October 1893, also had a lasting impact. This natural disaster destroyed the island of Chenière Caminada. About half the inhabitants were killed because of this disaster.

Early 20th century hurricanes

1909 saw the Grand Isle hurricane hit the city. There was major flooding in the "back of town" area and in the undeveloped swamps north of town.
The 1915 New Orleans hurricane, or as it was called locally, "the Great Storm of 1915" struck with more wind damage than the 1909 storm. Flooding was more limited in scope and duration due to improved drainage pumping. However, Lake Pontchartrain rose to a higher level than previously recorded, overtopping some of the back levees. The Sewage and Water Board recommended taller levees to protect the city from flooding on the lake side.
A much larger project to build up levees along the lake and extend the shoreline out by dredging began in 1927. As the city grew, there was increased pressure to develop lower-lying areas. A large system of canals and pumps was constructed to drain the land. Flooding containment efforts until the mid-20th century primarily focused on floods from the Mississippi River.
In 1947, the Fort Lauderdale hurricane struck the New Orleans area. There was moderate wind damage. Flood prevention was largely successful in Orleans Parish, but there was severe flooding in the new East Jefferson suburbs near the Lake.

Late 20th century hurricanes

in 1956 resulted in flooding in parts of Eastern New Orleans.
Hurricane Betsy in 1965 alerted a new generation to the threat posed by major hurricanes. As radar showed the storm heading for the city, a mandatory evacuation of Eastern New Orleans was declared. The Mississippi River-Gulf Outlet Canal channeled storm surge into the metro area. A levee failure was responsible for major flooding in the Lower 9th Ward.
The heavy flood damage caused by Hurricane Betsy brought concerns about hurricane flooding to the forefront. Betsy resulted in a major redesign of the levee system. By authorizing the United States Army Corps of Engineers to design and construct the flood protection, Congress essentially overrode responsibility for flood protection by the local levee boards. The Flood Control Act of 1965 directed the Corps of Engineers to plan for the maximum anticipated hurricane for the area.
The Corps of Engineers also designed a Lake Pontchartrain Hurricane Barrier to shield the city with flood gates like those which protect the Netherlands from the North Sea. Congress provided funding, and construction began in 1971. But the work stopped in 1977 when a federal judge ruled, in a lawsuit brought by the environmental group Save Our Wetlands, that the Corps' environmental impact statement was deficient. In 1985, after nearly a decade of court battles, the Corps scrapped the plan, and decided to reinforce the existing levee system instead.
The threat of 1969's Hurricane Camille was known in advance through improved radar technology and much of New Orleans braced for a repeat of Betsy. But Camille turned east and wreaked havoc on the Gulf coast of Mississippi and Alabama.
Hurricane Juan prompted a large evacuation from the city but did little damage.
Hurricane Andrew threatened the city in 1992. Clearly a major killer storm which had already devastated parts of south Florida, it prompted the largest evacuation of the city to date. Andrew turned west of the city but prompted re-evaluation of emergency evacuation procedures.
Hurricane Georges in 1998 precipitated an even larger evacuation. The Louisiana Superdome was opened as a shelter of last resort for those unable to evacuate, with unfortunate consequences as much of the venue was looted. Highways out of the city were tied up bumper to bumper, prompting development of the Contraflow lane reversal plan. The evacuation from Greater New Orleans and the Mississippi coast was the largest in U.S. history up to that point.
Georges missed the city, but it caused significant storm surge, raising the level of Lake Pontchartrain to the point that the city was spared major flooding only by the lake levees and flood walls. There was significant destruction to the areas just outside the flood walls, including at Little Woods and at West End near the mouth of the 17th Street Canal.

21st century

In early 2001, the Federal Emergency Management Agency, named three major scenarios as being among the most serious threats to the nation: a major hurricane hitting New Orleans, a terrorist attack in New York City, and a large earthquake hitting San Francisco. In 2004, a Corps of Engineers study was done on the cost and feasibility of protecting southeast Louisiana from a major Category 5 hurricane, including construction of floodgate structures and raising existing levees. The report also suggested that the chances of a major Category 5 hurricane directly striking New Orleans was a one-in-500-year event.

Warnings of dangerous vulnerability

In 2001, the Houston Chronicle published a story which predicted that a severe hurricane striking New Orleans, "would strand 250,000 people or more, and probably kill one of 10 left behind as the city drowned under of water. Thousands of refugees could end up in Houston." In 2002, The Times Picayune published a feature covering various scenarios, including a Category 5 hurricane hitting the city from the south. The series also explored the various environmental changes that have increased the area's vulnerability. One article in the series concluded that hundreds of thousands would be left homeless, and it would take months to dry out the area and begin to make it liveable. But there would not be much for residents to come home to. The local economy would be in ruins.
Many concerns focus around the fact that the city lies below sea level with a levee system that was designed for hurricanes of no greater intensity than Category 3. Furthermore, its natural defenses, the surrounding marshland and the barrier islands, have been dwindling in recent years. Just a few months before Katrina, the FX docudrama Oil Storm depicted a Category 4 hurricane hitting New Orleans, killing thousands of people and forcing residents to evacuate and hide out in the Superdome, and speculated about a national economic meltdown caused by the decreased oil supply.

Hurricane Isidore

in 2002 prompted some cautious New Orleanians to evacuate; the majority kept an eye on the news without leaving town. A state of emergency was declared a few days before landfall, and a curfew was also issued between 6 am and 10 pm. The Superdome was used as a "special needs" shelter for medical patients. There was relatively minor damage in the city; however, there was still some moderate flooding, with portions of Interstate 10 being closed due to rising water and the French Quarter being almost a foot underwater. The storm also shut down the Audubon Zoo.

LSU-USACE Study

In 2002 the Corps of Engineers, in conjunction with the Louisiana Water Resources Research Institute at Louisiana State University, and the authorities in Jefferson Parish, modeled the effects and aftermath of a Category 5 strike on New Orleans. The model predicted an unprecedented disaster, with extensive loss of life and property. The study identified the problem: the New Orleans area is like a bowl, surrounded by levees which are strongest along the outer Mississippi and primarily intended to contain river flooding. When a hurricane drives water into Lake Pontchartrain, the weaker levees bordering Pontchartrain and canals leading to it are overwhelmed. Water then flows into the below-sea-level city, accompanied by water overflowing the levees along the Mississippi on the south side of the city center.

Hurricane Ivan

In 2004 Hurricane Ivan's threat to the city resulted in the largest evacuation of the city to date. Mayor Ray Nagin issued a call for a voluntary evacuation of the city at 6 pm on September 13. An estimated 600,000 or more evacuated from Greater New Orleans. The contraflow plan was put into full effect for the first time, but rather late in the evacuation due to various confusions. This proved valuable practice, for the contraflow was implemented much more smoothly in 2005.