Corps To 'Armor' Levees To Protect Against Erosion

Jun 2, 2015

Army Corps of Engineers crews working on the levees along a stretch of Lake Pontchartrain.
Credit Paul Floro / Army Corps of Engineers

The Army Corps of Engineers held a public meeting to discuss a new project that will add fabric matting and natural grasses to the top of the levees along the lakefront. The design aims to protect from surges caused by a 100-year storm.

The Corps refers to this project as "armoring" the levees. The existing system is defined to withstand a hurricane with a 1 percent chance of occurring any given year: a "100-year storm." This armoring strategy is being put in place in case there’s an even stronger storm that breaches those levees.

“If the levee is overtopped, it will prevent erosion on the protected side of the levee,” says Brad Drouant, senior project manager with the Army Corps of Engineers. “One of the things people talk about is building wetlands, that’s one type that I know the state is looking at. Well, this is something that we’re doing to add resiliency.”

The Corps is planting Bermuda Grass on top of the fabricated matting, because that’s the species that best ensures erosion control if there’s overtopping. The armoring process has already begun in St. Charles Parish, and areas on the west bank. This portion of the project in Orleans Parish along the lakefront will be completed in July 2016. The eventual goal is for the entire levee system to undergo this upgrade. 

But the land underneath the levees continues to sink. This likely means the entire system needs to be lifted, as well as armored. The Corps weighs the risk of which to do first. Both types of upgrades means the levees are vulnerable while under construction.