Here_is_the_2007 risk assessment by the Corps. It is presented as the flood depth that areas of New Orleans will encounter after a 100 year storm. Flood depth estimates range from a foot (white) to over 8 feet (dark blue). On the eastbank a 100 year storm looks like a replay of Katrina. St. Bernard, the entire Ninth Ward, Gentilly, Lakeview, Mid and Central City all flood catastrophically. Metairie floods to a lesser extent. On the westbank which did not flood during Katrina, Algiers is drowned except at the point and along the levee. Gretna goes under along with Harvey, Lafitte and Avondale.

When will the 100 year protection Congress mandated in 1965 be provided?

Recalling the definition of a 100 year storm, it is the storm that will have a 1% probability of striking the area in any given year. Evaluating the independent probabilities, with this type of protection, you can expect to avoid this level of flooding for:

• 10 years with a 90% probability
• 20 years with a 82% probability
• 40 years with a 66% probability
• 68 years with a 50% probability
• 100 years with a 37% probability

Here_are_the_expected_flood_depths from a 500 year (Category 5) storm. Considering the independent probabilities. You are safe from this catastrophe:

• for 20 years with a 96% probability
  
• for 40 years with a 92% probability
• for 100 years with a 82% probability
  
• for 344 years with a 50% probability

Or it could happen this year. Bear in mind the idea that people who keep records have been living here since 1718, that's 289 years, and nothing like this flood has happened even before we put levees along the river.