section_path: Geography/Threat from tropical cyclones
section_name: Threat from tropical cyclones
paragraph_text: Threat from tropical cyclones
  
  Hurricanes pose a severe threat to the area, and the city is particularly at risk due to its low elevation, the city being surrounded by water from the north, east, and south, and Louisiana's sinking coast. According to the Federal Emergency Management Agency, New Orleans is the nation's most vulnerable city to hurricanes. Indeed, portions of Greater New Orleans have been flooded by the Grand Isle Hurricane of 1909, the New Orleans Hurricane of 1915, 1947 Fort Lauderdale Hurricane, Hurricane Flossy in 1956, Hurricane Betsy in 1965, Hurricane Georges in 1998, Hurricanes Katrina and Rita in 2005, Hurricane Gustav in 2008, Hurricane Isaac in 2012, Hurricane Zeta in 2020 (Zeta was also the most intense hurricane to pass over New Orleans) and Hurricane Ida in 2021. The flooding from Betsy was significant and in a few neighborhoods severe, and that from Katrina was disastrous for the majority of the city.
  
  On August 29, 2005, storm surge from Hurricane Katrina caused catastrophic failure of the federally designed and built levees, flooding 80% of the city. A report by the American Society of Civil Engineers says that "had the levees and floodwalls not failed and had the pump stations operated, nearly two-thirds of the deaths would not have occurred".
  
  New Orleans has always had to consider the risk of hurricanes, but the risks are dramatically greater today due to coastal erosion from human interference. Since the beginning of the 20th century, it has been estimated that Louisiana has lost 2,000 square miles (5,000 km 2) of coast (including many of its barrier islands), which once protected New Orleans against storm surge. Following Hurricane Katrina, the Army Corps of Engineers has instituted massive levee repair and hurricane protection measures to protect the city.
  
  In 2006, Louisiana voters overwhelmingly adopted an amendment to the state's constitution to dedicate all revenues from off-shore drilling to restore Louisiana's eroding coast line. U.S. Congress has allocated $7 billion to bolster New Orleans' flood protection.
  
  According to a study by the National Academy of Engineering and the National Research Council, levees and floodwalls surrounding New Orleans—no matter how large or sturdy—cannot provide absolute protection against overtopping or failure in extreme events. Rather, the city's levees and floodwalls should be viewed as a way to reduce risks from hurricanes and storm surges instead of eliminating those risks. For structures in hazardous areas and residents who do not relocate, the committee recommended major floodproofing measures (such as elevating the first floor of buildings to at least the 100-year flood level). Due to rising sea levels, most of New Orleans is at risk of being permanently underwater by the 2050s.