A look into why the levees failed during Hurricane Katrina?
November 13, 2016
Table of Contents
Abstract Page 3
Report Pages 4-7
Conclusion Page 8
Works Cited Page 9-10
Abstract
This research project is “A look into why the levees failed during Hurricane Katrina?” This report includes a brief description of the intensity, size and the destructive impact of Hurricane Katrina. It also states the observations of the levee failures at different sites and areas. There were five levees that are discussed in this report: the 17th Street Canal, London Avenue Canal – North, London Avenue Canal North - across from the breach, London Avenue Canal – South, and outside New Orleans.
There are so many myths, opinions, and facts regarding why the levees failed during Hurricane Katrina. Our research is to see if we can find out the facts.
Investigators found some structural reasons for the failure of the levees. The I-wall system is the type of floodwall protection system that was used with sheet piling. The coastal erosion that is occurring at such a fast pace and rate is negatively impacting the levee system. The sandy, brittle soil that does not have much strength in the foundation is a determining factor in the erosion. This does not set a strong foundation to act as the base to withhold the
Levees were implemented as the primary form of protection from the bodies of water surrounding the city. Moreover, officials recognized these structures were critical to protecting the city’s inhabitants given the city’s topography. However, a confluence of factors led to projects that were more immediately profitable being a top priority while simultaneously allowing the infrastructure critical to protecting the city deteriorate. Because of decisions to postpone upgrades and maintenance, the city’s chances of withstanding a hurricane of Katrina’s magnitude were decreased. Ultimately, the levee breaches caused the city’s destruction.
The failure to adequately prepare for the storm led to increased and more widespread devastation, which in many cases harmed those living in the affected areas. An independent analysis of the reason for such massive chaos was performed and determined that “Most of the damage was due to the failure of the levee system that surrounds the city to protect it from flooding” (Ubilla). Had these levees been properly built, and had there been more of them protecting the city of New Orleans, major flooding could have potentially been lessened. A simple feature of the levee structure which engineers neglected to include is the concrete
Hurricane Katrina was not New Orleans’ first time being hit with devastating effects from a hurricane. New Orleans has been struck by hurricanes six times over the past century. In 1915 was a category 4 hurricane, it killed 275 people and caused millions of dollars’ worth of damage. 1940, 1947, 1965, 1969 and again in 2005. The Mayor of New Orleans issued a first ever mandatory evacuation. With New Orleans being hit multiple times over the past decade surprised me that serious precautions weren’t taken previously, such as better levees or seawalls. Living in a place below sea level, one would think that the levees and seawalls would be stronger, but the levees collapsed below design height during the Katrina storm .
Levees are very helpful in a lot of ways and are needed to have a safe place to live, but they hurt the marshes that surround Louisiana. The levees that surround the Mississippi River are very good at their job and keep the river contained but with the river contained, there is no natural flooding that occurs in the coastal marshes and without the natural flooding, there is no depositing of sediment that replenishes and builds up the marsh. This creates an upset in the balance of land loss and land gained. The subsidence due to the lack of new sediment accounts for 53% of the land loss in Louisiana over the past
New Orleans was built on a marsh. The city was inundated by water during Hurricane Katrina in 2005, causing a tremendous loss of human lives and costing the economy billions of dollars in damage. Since the storm, the U.S. Army Corps of Engineers has built a system of lift stations and levees to control the flow of water around the city. This has created what is best described as a bathtub surrounded by water. To further elaborate, New Orleans is the bath tub, while Lake Pontchartrain and the Mississippi River surround the city. Over the years keeping water from entering the city has become more difficult because the city continues to sink lower below sea level. Subsidence of marshy soils lowers the ground elevation in and around the City of New Orleans. The gradual caving in or sinking of land is known as subsidence.
The chapter also mentions how the levees collapsed and filled the city with water; the author mentions how no one was prepared for this to happen. The author then talks about it took three days for helicopters to drop sand bags to prevent water from flowing in, however; the author mentions how this had failed because another hurricane hit and flooded the city yet
Hurricane Katrina. [Electronic Resource] : Wind Versus Flood Issues. Washington, DC : Office of Inspector General, U.S. Dept. of Homeland Security, [2008], 2008. EBSCOhost, excelsior.sdstate.edu/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=cat04225a&AN=sdsu.008408717&site=eds-live.
This decrease in intensity as Hurricane Katrina approached the southern United States was a result of the replacement of the storm’s eyewall. As the storm moved from the warm waters of the Loop current in the direction of the shore, rainstorms within Katrina robbed the eye of the storm of moisture. This process caused the replacement of the eye, and the reduction to the category three storm that made landfall in the vicinity of Buras, Louisiana on the morning of August 29, 2005. At this point, Hurricane Katrina’s storm surge was greater than 20 feet high. Though Buras, Louisiana was the location of landfall, Hurricane Katrina’s reach was much more vast: rampaging winds and the destruction of levees only added to the ruin this storm caused (Ahrens & Sampson, 2011).
New Orleans was originally founded on high ground overlooking the Mississippi River, above sea level. Also surrounded by Lake Pontchartrain and Lake Borgne, New Orleans was susceptible to hurricanes that would come up the coast into the Gulf. Originally New Orleans was naturally protected by “coastal swamps that helped absorb the energy of storm surges before they reached dry land.” (Stillman 228) At this point Americans were more concerned with the floods that happened annually from the Mississippi River. In the early days, settlers built a mile long levee to block overflows from the mighty Mississippi while landowners constructed their own levees.
Hurricane Katrina was the biggest natural calamity in the United States that led to immense loses. The storm affected 92, 000 square miles and damaged much of the major city. More 18, 000 individuals died and thousands became homeless, with no access to basic supplies. The disaster evolved into a sequence of linked series, with two primary causes. The basic cause was the storm itself, but no less significant was the breakdown of the artificial levees intended to safeguard a city constructed below the sea-level. These
The most significant implementations that were put into effect to protect the city of New Orleans were the levee and floodwall systems. Floodwalls are just as they appear to be. They are vertical walls that serve as barriers, in this case surrounding the city of New Orleans that is vulnerably sinking below sea level, in attempt to contain a river or waterway and prevent water from flooding the city. These floodwalls created a “fishbowl” effect, “with the water on the outside and half a million homes on the inside” (Flynn et al). However, the walls
Hurricane Katrina hit the southeastern coast of the United States in August of 2005. The eye of the storm went through the city of New Orleans and caused thousands of casualties and more than eighty billion dollars in damage (Schwartz). However, poor engineering and design allowed the immense flooding to breach the levee system and flood most of the metropolitan area. Despite the Delta Service Corps admitting that they knew of the possible failures for over twenty years, they claimed that insufficient budgets set by Congress and local governments prohibited them from restructuring and preserving the levees (Can We Save New Orleans?). Katrina was the third most intense land falling tropical storm in United States history. The combination of
The main big failure was the levee system. Three hundred fifty miles of levees and floodwalls that were created to protect the city of New Orleans failed and the flooding allowed the entire Ninth Ward and much more to be swept away. A field reporter described it as this after a few days of the flooding;
While the city did not take a direct hit, New Orleans also felt the impact of Katrina as she came ashore. The wind and rain from the storm put enormous stress on the levees protecting the city. Unfortunately, the levees could not withstand the forces applied to them and they eventually gave way flooding large portions of the city of New Orleans and surrounding areas. Large public places began to become places of refuge for those still in the
Numerous different aspects were altered due to the ruckus of Hurricane Katrina. The first major aspect was housing and location. Katrina nearly demolished 300,000 homes. The ascending sea level along the coast resulting from onshore winds is a storm surge. With a twenty-two foot storm surge in New Orleans and a twenty-seven foot storm surge in Mississippi, Hurricane Katrina averaged a shocking twelve foot storm surge. As a storm surge’s footage increases, the surge will continue to move inland farther and farther. Hurricane Katrina’s storm surge is documented as moving inland a total of twelve miles into the state of Mississippi (FAQS, 2013). Hurricane Katrina impacted a total of seven states. Five of these states were Georgia, Florida, Alabama, Mississippi, and Louisiana. Kentucky and Ohio were two more states affected but in a different way. Because of the tremendous amount of water, Kentucky and Ohio were victims of the Mississippi River flooding. Some states experienced more extreme destruction than others. Alabama, Mississippi, and Louisiana experienced Hurricane Katrina’s wrath firsthand. These three southern states were affected the worst by the massive storm (FAQS, 2013). Mississippi’s forest industry experienced a great amount of destruction losing 1.3 million acres of valuable forest land. The main cause of destruction in New Orleans was blamed on the failure of the levee system to stand its ground