Grey Infrastructure-Lake Borgne Surge Barrier
Channel: Sean Anderson
Date: 2023-03-22

A classic example of "hard" or "hardened" engineered solutions to coastal flooding is the Lake Borgne Surge Barrier constructed between 2008 and 2011 in the wake of the catastrophic flooding of the city of New Orleans thanks to dozens of failures of the levee protection system.

We are coming to increasingly refer to such structures as "grey" or "gray infrastructure" in contrast to the natural systems (aka "green infrastructure") which has worked so well for billions of years. 

This 1.8-mile-long Inner Harbor Navigation Canal (IHNC)-Lake Borgne Surge Barrier is located at the confluence of the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO), about 12 miles east of downtown New Orleans.

Project description from the US Army Corps of Engineers Website:

The 1.8-mile-long Inner Harbor Navigation Canal (IHNC)-Lake Borgne Surge Barrier is located at the confluence of the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO), about 12 miles east of downtown New Orleans. The surge barrier works in tandem with the Seabrook Floodgate Complex, which is being constructed at the north end of the IHNC (also known locally as the Industrial Canal) near Lake Pontchartrain. The projects reduce the risk associated with a storm surge that has a one percent chance of occurring in any given year, or a 100-year storm surge, for some of the areas hardest hit by Hurricane Katrina, including New Orleans East, metro New Orleans, Gentilly, the Ninth Ward and St. Bernard Parish. The total construction value for the IHNC-Lake Borgne Surge Barrier is an estimated $1.1 billion.