New Orleans Levees and Floodwalls

Since my trip down to the Lower Ninth Ward and St. Bernard Parish, a professor at Tulane has provided a lot more information to me regarding the levees and floodwalls. A number of factors combined to create the disastrous flooding of New Orleans. The main damage was caused by breaches in the floodwalls of the 17th Street, London Avenue, and Industrial Canals. The walls were moored in weak peat soil that had was especially vulnerable to water. The soil was a poor choice for the the floodwalls to be built upon. In addition, they were not anchored deep enough into the ground. Army Corps of Engineers plans called for the walls to be anchored 17 feet into the ground, but in some places they were only anchored 10 feet. Even that 17 feet was not deep enough. It turns out that much sturdier clay soil existed 25-50 feet down. The levees are strongest where they are found naturally along the Mississippi River and other places. They are large earthen mounds that can and have been overtopped.

Taken together, the floodwalls and levees need to designed smarter and built stronger to protect New Orleans in the future.