Corps of Engineers headquarters building on Leake Avenue is the last fix on our levees.
A contractor has resumed building a floodwall to plug a major low spot in the Mississippi River levee – at the Army Corps of Engineers‘ own New Orleans headquarters at Riverbend – after water levels in the Mississippi River dropped below 11 feet in late May. The $8.9 million project includes installation of sheet piling and long H-shaped batter piles to support the permanent and movable walls. It will elevate one of the last segments of the river levee system to assure protection from a river flood with a 1 percent chance of occurring in any year, a so-called 100-year flood. The existing, mostly earthen levee running through the Corps campus at 7400 Leake Ave. is 3 feet to 5 feet lower than the 100-year levee. Water topping the levee system there could flood much of New Orleans’ east bank.nola.com
The project will have movable walls so that parking and other things can be done unless the river is in flood stage. There will also be concrete scour protection on the batture and extending into the river. The project provides 3,000 feet of levee system that is supposed to be at least 24½ feet above sea level, but 500 feet or more is at least 5 feet lower and the rest is 2 to 5 feet too low. This is one of the last “holes” to be fixed in the protection for the New Orleans area.
In recent years, the Corps has station sand-filled Hesco baskets and other materials in the headquarters parking lot, in case they needed to be moved quickly into place along the low areas to prevent the river from topping the levee. Proposed in the 1990s and funded by Congress in 2019, the project has been delayed by high river periods during the past few years. Construction is expected to be complete in early 2022. Construction was halted in March when the river rose above 11 feet at the Carrollton gauge, which is at Corps headquarters. The water stayed above 11 feet for 79 days.
At the Corps headquarters the official river flood stage is 17 feet but with protections to 25 feet – except at their headquarters! It is interesting that high water stops being able to protect from high water.