New Orleans area hurricane levee system: West Closure Complex

The West Closure Complex at the Gulf Intracoastal Waterway south of Harvey is part of the overhaul of the metro New Orleans hurricane levee system that Congress authorized after Hurricane Katrina. The upgraded system is designed to keep out surges caused by a so-called 100-year storm, one with a 1 percent chance of hitting in any year. The system is also designed to significantly reduce flooding from even larger storms.

Project: Giant gates, protecting to 16 feet above sea level, would seal off much of West Jefferson and Algiers and a section of Plaquemines Parish from surges moving north through Barataria Bay from the Gulf of Mexico. And huge pumps will dump West Bank rainwater runoff from the reinforced Harvey and Algiers canals over the gates into the marshes to the south. The project cost $1 billion.

Notable feature: The closure's 11 pumps that can fill an Olympic swimming pool in four seconds, making it the largest drainage pump station in the world. It also includes a 225-foot navigable floodgate. 

Construction status: Completed.