Hurricane preparedness for New Orleans

Hurricane preparedness in New Orleans has been an issue since the city's early settlement because of the city's location.

New Orleans was built on a delta marsh. Unlike the first two centuries of its existence, today, a little less than half of the modern city sits below sea level. The city is surrounded by the Mississippi River to the south, Lake Pontchartrain to the north, and Lake Borgne to the east.

The parts of New Orleans and the surrounding communities first settled in the colonial era through the 19th century were and still are above sea level. However flooding was long a threat, from the periodic high waters of the Mississippi and more occasional severe storms which would push 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 originally erected to prevent damage caused by seasonal flooding. On the lakeside, much of the land was undeveloped swamp and only small levees were constructed 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 of 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 was hit by two hurricanes in addition to a major fire.

19th century hurricanes

The 19th century saw such hurricanes as the 1856 Last Island Hurricane and the 1893 Chenier Caminanda Hurricane.

Early 20th century hurricanes

1909 saw the Grand Isle Hurricane of 1909 hit the city. There was major flooding of "back of town" area and the undeveloped swamps north of town.

1915: The New Orleans Hurricane of 1915 or as it was commonly 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 higher 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 areas. A large system of canals and pumps was constructed to drain the city. Flooding containment efforts until the mid-20th century primarily focused on floods from the Mississippi River.

The 1947 Fort Lauderdale Hurricane hit the New Orleans area. The metro area suffered moderate hurricane wind damage. Flood prevention was largely successful in the city, but there was severe flooding in the new East Jefferson suburbs.

Late 20th century hurricanes

Hurricane Flossy in 1956 resulted in flooding in parts of Eastern New Orleans.

Hurricane Betsy in 1965 alerted a new generation to the threat of major hurricane hits. As radar showed the storm heading for the city, a mandatory evacuation of Eastern New Orleans was declared. The Mississippi River-Gulf Outlet Canal channel storm surge into the metro area. A levee failure was responsible for major flooding in Lower 9th Ward.

The heavy flooding caused by Hurricane Betsy brought concerns regarding flooding from hurricanes to the forefront. Betsy resulted in major redesign of levee system. Congress removed responsibility for the local flood protection from the local levee boards and authorized the US Army Corps of Engineers to design and construct the flood protection for the maximum anticipated hurricane for the area. (This project was still under construction when the city was hit by Katrina 40 years later.)

The Army Corps of Engineers also designed a Lake Pontchartrain Hurricane Barrier to shield the city with flood gates like those that protect the Netherlands from the North Sea. Congress provided funding and construction began in 1971, but work stopped in 1977 when a federal judge ruled, in a suit brought by 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 on reinforcing the city’s levee system instead. [Schoenbrod, David. "The Lawsuit That Sank New Orleans" "Wall Street Journal;' September 26, 2005.]

The threat of Hurricane Camille was shown in advance by improvement in radar technology, and much of New Orleans braced for a repeat of Betsy. However instead Camille turned east to hit the Mississippi Gulf Coast.

Hurricane Juan (1985) prompted a large evacuation from the city, but did little damage.

Hurricane Andrew threatened the city in 1992. Clearly a major killer storm that had already devastated parts of South Florida, it prompted the largest evacuation of the city to date. The storm turned west of the city, but prompted re-evaluation of emergency evacuation plans.

Hurricane Georges in 1998 prompted 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 Dome was looted. Highways leaving the city were tied up bumper to bumper, prompting development of the Contraflow lane reversal plan. The evacuation from Greater New Orleans and the nearby Mississippi Coast was the largest evacuation in U.S. history up to that time. [http://www.srh.noaa.gov/lix/html/top10.htm]

Georges missed the city, but it caused significant storm surge which raised the level of Lake Pontchartrain to the point that the city was saved from major flooding only by the lake levees and floodwalls. There was significant destruction to the areas just outside of the floodwalls, 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 (FEMA), named three major scenarios as being among the most serious threats to the nation: (1) a major hurricane hitting New Orleans, (2) a terrorist attack in New York City, and (3) a large earthquake hitting San FranciscoBerger, Eric. " [http://www.hurricane.lsu.edu/_in_the_news/houston.htm Keeping its head above water: New Orleans faces doomsday scenario] ." "Houston Chronicle." December 1, 2001.] . In 2004, an Army Corps of Engineers study was done on the costs 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. [Lincoln, Eric. " [http://www.mvn.usace.army.mil/pao/Riverside/Sept-Oct_04_Riv.pdf Old plans revived for Category 5 hurricane protection] ." "Army Corps of Engineers." September-October, 2004.]

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 convert|20|ft|m of water. Thousands of refugees could land 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 wouldn't be much for residents to come home to. The local economy would be in ruins. [McQuaid, John; Schleifstein, Mark. " [http://www.nola.com/hurricane/?/washingaway/index.html Washing Away] ." "Times Picayune." June 23-27, 2002.] 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. [Westerink, J.J.; Luettich, R.A. " [http://www.pubs.asce.org/ceonline/ceonline03/0603feat.html The Creeping Storm] ." "Civil Engineering Magazine." June, 2003.] Furthermore, its natural defenses, the surrounding marshland and the barrier islands, have been dwindling in recent years.Bourne, Joel K. " [http://magma.nationalgeographic.com/ngm/0410/feature5/ Gone with the Water] ." "National Geographic." October, 2004.] Just a few months before Katrina, the FX docudrama "Oil Storm" depicted a Category 4 hurricane hitting New Orleans 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

Hurricane Isidore in 2002 prompted some cautious New Orleanians to evacuate; the majority kept an eye on the news without leaving town.

LSU ACOE Study

In 2002 the Army Corps of Engineers, in conjunction with the Louisiana Water Resources Research Institute at Louisiana State University (LSU), 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. [" [http://americanradioworks.publicradio.org/features/wetlands/hurricane1.html Hurricane Risk for New Orleans] ." "American RadioWorks." September, 2002.]

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 6pm 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.

Hurricane Pam exercise

Hurricane Pam was a hypothetical hurricane used as a disaster scenario to drive planning for a 13-parish area in Southeastern Louisiana, including the city of New Orleans, in 2004. [News Release. " [http://www.fema.gov/news/newsrelease.fema?id=13051 Hurricane Pam Exercise Concludes] ." "Federal Emergency Management Agency." July 23, 2004.] [News Release. " [http://www.ieminc.com/Whats_New/Press_Releases/pressrelease060304_Catastrophic.htm IEM Team to Develop Catastrophic Hurricane Disaster Plan for New Orleans & Southeast Louisiana] ." " [http://www.ieminc.com/ IEM] ." June 3, 2004.] Developed by the Federal Emergency Management Agency, the Louisiana Office of Homeland Security, Emergency Preparedness, the National Weather Service, and Innovative Emergency Management, Inc., the mock hurricane scenario and its projected consequences were the focal point of an eight-day exercise held at the State Emergency Operations Center in Baton Rouge in July, 2004. Hurricane Pam was a slow-moving Category 3 storm with sustained winds of 120 mph. It brought with it up to convert|20|in|mm of rain to some parts of southeastern Louisiana and caused levee-topping storm surge. The consequence assessment for Hurricane Pam indicated that more than one million people would be displaced and that 600,000 buildings would be damaged, with some completely destroyed. The report on the simulation, TIME reported, warned that transportation would be a major problem in any storm situation paralleling the fictional "Hurricane Pam." [ [http://www.time.com/time/magazine/article/0,9171,1103591,00.html 1 The Mayor] Amanda Ripley. TIME. September 13, 2005. ]

Follow-on Hurricane Pam workshops were conducted in November/December 2004, July 2005, and August 2005.

The Hurricane Pam scenario and the level of attention that the federal government paid to it were discussed following the catastrophic effects of Hurricane Katrina on New Orleans in November and December, 2005. [Beriwal, Madhu. " [http://www.colorado.edu/hazards/o/nov05/nov05d2.html Hurricanes Pam and Katrina: A Lesson in Disaster Planning] ." "Natural Hazards Observer." November 2, 2005.] [Beriwal, Madhu; Moore, Avagene. " [http://www.emforum.org/vforum/lc051214.htm Hurricane Pam and Hurricane Katrina: Pre-event 'Lessons Learned'] ." "EIIP Virtual Forum Presentation." December 14, 2005.]

On January 25, 2005, the Louisiana Sea Grant forum discussed additional results of several simulations of strong hurricanes hitting New Orleans. [" [http://www.laseagrant.org/forum/01-25-2005.htm Presidents' Forum on Meeting Coastal Challenges] ." "Louisiana Sea Grant." January 25, 2005.]

Hurricane Cindy

Hurricane Cindy hit Louisiana at just barely hurricane strength on July 5, 2005. Many New Orleanians paid it little attention in advance, some having gotten blasé about threats of hurricanes which for decades had missed the city. However Cindy's winds gusted to convert|70|mi/h|km/h|abbr=on in the city, knocking branches off trees and causing New Orleans' largest blackout since Hurricane Betsy in 1965.cite web|author=National Hurricane Center|title=Tropical Cyclone Report: Hurricane Cindy|publisher=NOAA|date=2006-02-14|accessdate=2006-05-15|format=PDF|url=http://www.nhc.noaa.gov/pdf/TCR-AL032005_Cindy.pdf] The experience encouraged many to evacuate when the much more powerful Hurricane Katrina was heading towards the city less than two months later.cite web|author=Niki King|publisher=The Roanoke Times|date=2005-12-05|accessdate=2008-08-12|title=Katrina victims make Christiansburg a home|url=http://www.roanoke.com/news/nrv%5Cwb/43728] cite web|author=Karen Gleason|publisher=Del Rio News-Herald|date=2005-09-11|accessdate=2008-08-12|title=Louisiana family calling Del Rio home|url=http://www.delrionewsherald.com/story.lasso?ewcd=8d3a20080e1b17ef]

Hurricane Katrina

Hurricane Katrina threatened the city in August 2005. The eye of the huge storm grazed the eastern side of the city, sparing it from the worst of its power. However, due to poorly designed levees and the worst civil engineering failure in United States history, most of the city experienced flooding similar to a direct hit; see: Levee failures in Greater New Orleans, 2005.

There were many predictions of hurricane risk in New Orleans before Katrina. [Wilson, Jim. " [http://www.popularmechanics.com/science/research/1282151.html New Orleans is Sinking] ." "Popular Mechanics." September 11, 2001.] Fischetti, Mark. " [http://www.sciam.com/article.cfm?articleID=00060286-CB58-1315-8B5883414B7F0000 Drowning New Orleans] ." "Scientific American." October, 2001.] [Mooney, Chris. " [http://www.prospect.org/web/page.ww?section=root&name=ViewWeb&articleId=9754 Thinking Big About Hurricanes] ." "The American Prospect." May 23, 2005.]

On August 26 the storm, at one point up to a Category 5, was in the Gulf with a projected to possibly hit New Orleans a few days later. (The previous day the projected path was towards the Florida Panhandle.) On August 27 Mayor Nagin declared a state of emergency and called for a voluntary evacuation. The following day he issued the city's first ever whole-city mandatory evacuation order. A mandatory evacuation order is an extreme measure: the most recent such order in Louisiana occurred when east New Orleans was ordered evacuated in 1965.

There have been various plans to mitigate or prevent catastrophes. The evacuation plans were the most successful. The contraflow worked relatively smoothly, and over 80% of the population succeeded in fleeing the area in advance of the storm. The evacuation no doubt saved thousands of lives. However beyond the evacuation of those willing and able to leave town through their own resources, almost every other aspect of preparedness was found dreadfully wanting.

Like many other cities, New Orleans heavily relied on evacuation in case of a Category 5 storm. The inadequacy of evacuation plans was shown up when no provision was made in time to evacuate the large number of peoplendash elderly, disabled, those without carsndash who could not leave by their own means.

Blame for lack of preparedness has been leveled at all levels of government. New Orleans Mayor Ray Nagin has been criticized for not following the city's evacuation plan which called for the use of school buses to transport disadvantaged and elderly citizens out of the city. Louisiana Governor Kathleen Blanco was also criticized for not deploying the Louisiana National Guard sooner, although she did in fact deploy them before the hurricane hit and requested reinforcements from other states. President George W. Bush and Homeland Security Secretary Michael Chertoff were also criticized for failures on the federal level as well as with his leadership role. [Glassner, Susan B.; White, Josh. " [http://www.washingtonpost.com/wp-dyn/content/article/2005/09/03/AR2005090301653.html Storm Exposed Disarray at the Top] ." "Washington Post." September 4, 2005.] FEMA chief Michael D. Brown admitted on the 1 year anniversary of landfall that "There was no plan" [http://www.wdsu.com/news/9754112/detail.html?rss=no&psp=news] and claimed that in the immediate aftermath of the disaster White House officials told him to lie to put a more positive spin on the Federal response. [http://www.msnbc.msn.com/id/14570837/]

The designation by the city of the Louisiana Superdome as the "shelter of last resort" proved poor. It did not meet the safety standards required for a Red Cross shelter and thus it was not staffed by them or the Salvation Army. Thousands were trapped inside it as the area around it flooded and part of the roof blew off. Provisions for food and water were just barely adequate; sanitation, medical, and crowd control did not achieve that level.

Under the National Response Plan, disaster planning is first and foremost a local government responsibility. On the day after the Hurricane, Michael Chertoff invoked the National Response Plan, transferring emergency authority to the Department of Homeland Security.

Civil order broke down, infrastructure failed, and some 80% of the city flooded. A few government responders, including Coast Guard helicopters and Louisiana Fisheries & Wildlife Boats, responded early and worked hard to save lives of people stranded in the flooding, but their numbers were inadequate for the scope of the disaster. Private volunteers with boats assisted with rescue in great numbers, but significant Federal response was largely absent until 5 days after the disaster.

ee also

*Effect of Hurricane Katrina on New Orleans
*Hurricane Katrina effects by region

Post-Katrina

The next major hurricane threat to the city after Katrina came less than a month later, as Hurricane Rita headed towards the Gulf Coast as the city was still in ruins. Repopulation of some parts of the city had just begun [cite web|url=http://solarnavigator.net/hurricane_rita.htm|author=Solar Navigator|title=Solar Navigator|accessmonthday=26 June|accessyear=2007|language=English] when it was canceled and the city orded re-evacuated. The levee system again failed, re-flooding low-lying portions of the city such as the Lower Ninth Ward.cite web|url=http://benfieldgroup.com/NR/rdonlyres/CF56C1E5-18B9-4518-BBBA-BBCCA3EE662E/0/Report_HU_Rita.pdf |author=Benfield Inc.|title=Catastrophe Perspectives|accessmonthday=26 June|accessyear=2008|language=English]

Hurricane Ernesto in 2006 originally threatened Louisiana before hitting Florida, causing early preparations and rising oil prices. [cite news| author = Peter Henderson | title = Louisiana on alert for Tropical Storm Ernesto | date = August 26, 2006 | accessdate = 2006-08-26 | publisher = Reuters | url = http://abcnews.go.com/US/wireStory?id=2360276] [cite news | author = Brad Foss | title = Oil Rises As Traders Watch Iran, Storm | date = August 26, 2006 | accessdate = 2006-08-26 | publisher = Associated Press | url = http://abcnews.go.com/Business/wireStory?id=2356301&CMP=OTC-RSSFeeds0312]

Making landfall in Louisiana in late August 2008 as a category two hurricane, Hurricane Gustav was the first to put large scale preparations in motion, although the storm was still in Caribbean on the third anniversary of Katrina. Locals were warned to prepare for a possible evacuation of the city and additional National Guard units were called out, and a state of emergency was declared. [cite web|url=http://www.nola.com/hurricane/index.ssf/2008/08/those_who_need_help_to_leave_c.html|title=Those who need help to leave can call|date=August 28, 2008|publisher=Times-Picayune|accessdate=2008-09-23] [cite web|url=http://www.usatoday.com/weather/hurricane/2008-08-28-Gustav-New-Orleans_N.htm|title=http://www.usatoday.com/weather/hurricane/2008-08-28-Gustav-New-Orleans_N.htm|last=Jervis|first=Rick|coauthors=Leinwand, Donna|date=August 29, 2008|publisher=USA Today|accessdate=2008-09-23] [cite news|url=http://www.nola.com/hurricane/index.ssf/2008/08/gov_bobby_jindal_declares_pres.html|title=Gov. Bobby Jindal declares pre-storm state of emergency (and Lake Charles' dominance)|last=Barrow|first=Bill|date=2008-08-27|publisher=New Orleans Times-Picayune|accessdate=2008-08-27] Soon afterwards, 1.9 million people were evacuated from southern Louisiana, including 200,000 from the City of New Orleans. Contraflow lanes were again initiated. [cite web|author=Mark Schleifstein|publisher=The Times-Picayune|date=2008-08-26|accessdate=2008-08-27|title=Louisiana gears up for Gustav as it makes landfall in Haiti|url=http://www.nola.com/news/index.ssf/2008/08/louisiana_gears_up_for_gustav.html|archiveurl=http://www.webcitation.org/5aNv3QZxX|archivedate=2008-08-27] [cite news|url=http://www.cnn.com/2008/US/weather/08/31/gustav/index.html|title=Bush tells Gulf Coast residents to flee 'dangerous' storm|last=Staff writer|date=2008-08-31|publisher=CNN|accessdate=2008-08-31] Forty-three deaths occured in Louisiana as a result of the storm. [ [http://www.nola.com/news/t-p/capital/index.ssf?/base/news-6/122128337353780.xml&coll=1 "14 more deaths tied to Gustav,"] The Times-Picayune, September 13, 2008]

Levee preparations and funding issues

Southeast Louisiana Project funding:

2004:

*Army Corps request: $11 million
*Bush request: $3 million
*Approved by Congress: $5.5 million

2005:

*Army Corps request: $22.5 million
*Bush request: $3.9 million
*Approved by Congress: $5.7 million

2006:

*Bush request: $2.9 million [Roberts, Deon. " [http://www.findarticles.com/p/articles/mi_qn4200/is_20050606/ai_n14657367 New Orleans district of the U.S. Army Corps of Engineers faces] ." "New Orleans City Business." June 6, 2005. Retrieved on July 14, 2006.]

While no detailed proposals had yet been made to augment the New Orleans levee system to be capable of withstanding a category 4 or greater hurricane, in October 2004, senior U.S. Army Corps of Engineers project manager Al Naomi submitted a proposal to Congress requesting $4 Million to fund a preliminary study for such a plan. Congress tabled the proposal, never addressing it on the floor, citing budgetary concerns resulting from the Iraq War. Naomi's off-hand estimate was that this project would require approximately $1 Billion dollars and would take 20 years. Naomi had stated, "It's possible to protect New Orleans from a Category 5 hurricane... we've got to start. To do nothing is tantamount to negligence." [Nussbaum, Paul. " [http://hurricane.lsu.edu/_in_the_news/phillyinquirer100804.htm New Orleans' growing danger] ." "The Philadelphia Inquirer." October 8, 2004.] Whether or not such additional funding might have been capable of preventing the extensive flooding in New Orleans caused by Katrina, is a matter that has yet to be determined.

Starting in 2003, federal spending on the Southeast Louisiana Project was substantially reduced. Lt. General Carl Strock, Chief of Engineers at the Army Corps of Engineers, said that, "at the time that these levees were designed and constructed, it was felt that that was an adequate level given the probability of an event like this occurring." Strock also said that he did not believed that funding levels contributed to the disaster, commenting that, "the intensity of this storm simply exceeded the design capacity of this levee." Strock also told reporters that the Corps of Engineers, "had a 200- or 300-year level of protection. That means that an event that we were protecting from might be exceeded every 200 or 300 years." [News Transcript. " [http://www.dod.mil/transcripts/2005/tr20050902-3847.html Defense Department Special Briefing on Efforts to Mitigate Infrastructure Damage from Hurricane Katrina] ." "United States Department of Defense." September 2, 2005.]

From 2001 through 2005, the Bush administration battled with Congress to cut a total of approximately 67% from the budgetary requests from the Army Corps of Engineers for levee augmentation projects in the New Orleans area, but ultimately settled with Congress on a 50% cut in these budgetary requests. In February 2004, Naomi stated that, "I've got at least six levee construction contracts (in the New Orleans area where funding has been cut) that need to be done to raise the levee protection back to where it should be (because of settling). Right now I owe my contractors about $5 Million. And we're going to have to pay them interest." [Bunch, Will. " [http://alternet.org/story/24871/ Why the Levee Broke] ." "AlterNet." September 1, 2005.]

Even as the Bush administration was cutting the Army Corps of Engineers budget, many were criticizing the administration for not cutting the budget more. The "New York Times", in particular, published several editorials criticizing the large size of the $17 Billion Corps budget, and called for the Senate to cut, "pork," in S. 728, which would have provided $512 Million in funding for hurricane protection projects in southern Louisiana. [Sheppard, Noel. " [http://www.americanthinker.com/articles.php?article_id=4796 The American Thinker] ." "The American Thinker." September 6, 2005.]

Just after Hurricane Katrina hit, there was some concern expressed that government officials have placed an overemphasis on disaster recovery, while neglecting the process of pre-planning and preparation. [Walsh, Bill; Alpert, Bruce; McQuaid, John. " [http://www.newhousenews.com/archive/alpert083105.html Feds' Disaster Planning Shifts Away from Preparedness] ." "Newhouse News Service." August 31, 2005.]

In the 17 months following Katrina, five investigations were carried out. The only federally ordered study was sponsored and managed by the Army Corps of Engineers [ [http://www.nola.com/weblogs/nola/index.ssf?/mtlogs/nola_nolaview/archives/2006_06_01.html NOLA View weblog ] ] . Two major independent studies were done by the University of California at Berkeley [ [http://www.ce.berkeley.edu/%7Enew_orleans/ ILIT DOWNLOAD CENTER (sponsored in part by the National Science Foundation) ] ] and the Louisiana State University. [http://www.dotd.louisiana.gov/administration/teamlouisiana/TeamLaLetter.pdf] Two minor studies were done by FEMA and the insurance industry. All five studies basically agree on the engineering mechanisms of failure.

The failure mechanisms included overtopping of levees and floodwalls by the storm surge, consequential undermining of flood wall foundations or other weakening by water of the wall foundations, and the storm surge pressures exceeding the strength of the floodwalls. In June 2006, a contrite Lt. Gen Carl Strock took responsibility for the failure of metro New Orleans flood protection, calling the system "a system in name only." [ [http://www.iht.com/articles/2006/06/01/news/orleans.php Army engineers admit levees were badly made - International Herald Tribune ] ]

As of August 2006, the Army Corps of Engineers planned to spend $6 billion to make sure that by 2010, the city would probably be flooded only once every 100 years. But this would not equal the best levee system in the world, which is in The Netherlands. That system is designed to protect populated areas against anything but a 1-in-10,000-years flood. If the Corps built a 1-in-500-year levee system in New Orleans, Ivan van Heerden, deputy director of Louisiana State University's Hurricane Center, says, it would cost $30 billion. [ [http://www.time.com/time/magazine/article/0,9171,1229102,00.html Why We Don't Prepare, Amanda Ripley. TIME. August 20, 2006.] ]

Louisiana's sinking coast

When the Army Corps of Engineers started systematically leveeing the river in the 19th century, it cut off the region's main source of silt, the raw material of delta-building in the Mississippi Delta and the Wetlands of Louisiana.cite book|last=Tidwell|first=Mike|title="The Ravaging Tide: Strange Weather, Future Katrinas, and the Coming Death of America's Coastal Cities|publisher=Free Press|date=2006|isbn=0-7432-9470-X] The weight of large buildings and infrastructure and the leaching of water, oil and gas from beneath the surface across the region have also contributed to the problem. Following the great floods of 1927, the Mississippi River was surrounded by a series of levees meant to protect the city from such floods. In 1965, New Orleans was hit by Hurricane Betsy, which caused tremendous flooding in the New Orleans area. The federal government began a levee-building program to protect New Orleans from a Category 3 hurricane (the same strength as Betsy). These series of levees were completed in recent years before Hurricane Katrina.

However, an unintended consequence of the levees was that natural silt deposits from the Mississippi River were unable to replenish the delta, causing the coastal wetlands of Louisiana to wash away and the city of New Orleans to sink even deeper. The Mississippi River delta is subsiding faster than any other place in the nation. While the land is sinking, sea level has been rising. In the past 100 years, land subsidence and sea-level rise have recently added three feet to all storm surges. That extra height puts affected areas under deeper water; it also means flooding from weaker storms and from the outer edges of powerful storms spreads over wider areas. The marshes that ring New Orleans, as well as the land depression of the city itself, originally above sea level, have sunk the quickest.

The problem with the wetlands was further worsened by salt water intrusion caused by the canals dug by the oil companies and private individuals in this marshland. This erosion of the wetlands not only caused Louisiana to lose convert|24|sqmi|km2 per year of land annually and convert|1900|sqmi|km2 of land since the 1930s, but it also destroyed Louisiana’s first line of defense against hurricanes.

Hurricanes draw their strength from the sea, so they quickly weaken and begin to dissipate when they make landfall. Hurricanes moving over fragmenting marshes toward the New Orleans area can retain more strength, and their winds and large waves pack more speed and destructive power. Scientists working for the Louisiana Department of Natural Resources measured some of these effects during Hurricane Andrew in 1992. Andrew's surge height dropped from convert|9.3|ft|m at Cocodrie to convert|3.3|ft|m at the Houma Navigation Canal convert|23|mi|km to the north. For every mile of the marsh-and-water landscape it traversed, it lost 3.1 inches of height, sparing some homes farther north from more flooding. Currently Louisiana has 30% of the total coastal marsh and accounts for 90% of the coastal marsh loss in the lower 48 states. The engineering of the river has basically brought the Gulf of Mexico much closer New Orleans, making it more vulnerable to hurricanes.

The combination of sinking land and rising seas has place the Mississippi River delta as much as convert|3|ft|m lower relative to sea level than it was a century ago, and the process continues. That means hurricane floods driven inland from the Gulf have risen by corresponding amounts. Storms that once would not have had much impact can now be devastating events, and flooding now penetrates into places where it has rarely occurred before. The problem also is slowly eroding levee protection, cutting off evacuation routes sooner and putting dozens of communities and valuable infrastructure at risk of being wiped out by the flooding.

State and federal officials have recently pushed a $14 billion plan to rebuild wetlands over the next 30 years, to be funded by oil and gas royalties, called Coast 2050. [" [http://www.coast2050.gov/ Coast 2050] ." Accessed April 2, 2006.] Louisiana will receive $540 Million under the energy bill enacted in August 2005. More money for this program is likely to come with aid from Hurricane Katrina. The original actual cost needed for the project, however, was $14 billion.

Wetlands have the capacity to absorb storm surges at the rate of convert|1|ft|m|sing=on per convert|2.7|mi|km. However, due to the systematic, long-term nature of wetland loss, and because wetland remediation can take decades, [Schleifstein, Mark. " [http://www.nola.com/hurricane/index.ssf?/washingaway/futureofcoast_1.html Coastal Resuscitation] ." "Times Picayune." June 23-27, 2002.] it is not possible to pinpoint blame for wetland loss on any specific Congress, legislature, President, or governor.

ee also

*Drainage in New Orleans
*"Hurricane on the Bayou"

References

External links

* [http://www.levees.org Levees.Org (non-profit in New Orleans)]
* [http://www.ohsep.louisiana.gov/plans/eopindex.htm State of Louisiana Emergency Operations Plan]
* [http://www.cityofno.com/portal.aspx?portal=46&tabid=26 City of New Orleans Hurricane Preparedness Plan]
* [http://www.pbs.org/wgbh/nova/sciencenow/3204/02.html Nova Television Show on hurricane threat to New Orleans]
* [http://www.ce.berkeley.edu/~new_orleans/ Independent Levee Investigation Team Draft Report]
* [http://www.dcmessageboards.com/index.php?showtopic=5618 Hurricane Katrina Blame Game]
* [http://www.katrina.house.gov/full_katrina_report.htm Final Report: U.S. House of Representatives Select Bipartisan Committee to Investigate the Preparation for and Response to Hurricane Katrina]