New Orleans' Hurricane and Storm Damage Risk Reduction System includes 23 miles of floodwall in St. Bernard Parish, and a surge barrier in the Inner Harbor Navigation Canal.

The floodwall incorporates “T-Wall” construction to increase the existing height of the wall from 20 feet in most areas to 32 feet in some areas. The floodwall's foundation are made either of steel “H” piles or concrete piles driven at an angle down as far as 100 feet to add support. Between 300,000 and 500,000 cubic yards of concrete will be required to construct the floodwall.

The surge barrier is the largest design-build project for the U.S. Army Corps of Engineers. At the epicenter of the project are 144-foot-long concrete piles cast in both 6-inch and 2-foot diameters, depending on their function. Some 3-foot square piles will be located at floodgates to the canal entrances. A total of 1274 concrete tubes will be driven 130 feet deep and then filled with concrete and steel reinforcement to support the surge barrier. Horizontal precast pile caps measuring 17x15x6 feet are placed on top of the piles and secured with cast-in-place concrete.

View more enduring mega projects.