The 1.8-mile-long Inner Harbor Navigation Canal-Lake Borgne Surge Barrier is located at the confluence of the Gulf Intracoastal Waterway and the Mississippi River Gulf Outlet, about 12 miles east of downtown New Orleans. The surge barrier works in tandem with the Seabrook Floodgate Complex, which was built at the north end of the IHNC near Lake Pontchartrain. The projects reduce the risk associated with a storm surge that has a one percent change of occurring in any given year. Both are part of the $14.6 billion Hurricane and Storm Damage Risk Reduction System being built by the U.S. Army Corps of Engineers. The IHNC is also the largest design-build civil works project in the history of the U.S. Corps of Engineers. The entire structure is 25 and 26 feet above sea level with a 56-foot-wide vertical lift gate at Bayou Bienvenue.