The Inner Harbor Navigation Canal (IHNC) Seabrook Floodgate Structure is a

flood barrier A flood barrier, surge barrier or storm surge barrier is a specific type of floodgate, designed to prevent a storm surge or spring tide from flooding the protected area behind the barrier. A surge barrier is almost always part of a larger flood ...

in the

Industrial Canal The Industrial Canal is a waterway in New Orleans, Louisiana, United States. The waterway's proper name, as used by the U.S. Army United States Army Corps of Engineers, Corps of Engineers and on NOAA nautical charts, is Inner Harbor Navigation ...

New Orleans New Orleans (commonly known as NOLA or The Big Easy among other nicknames) is a Consolidated city-county, consolidated city-parish located along the Mississippi River in the U.S. state of Louisiana. With a population of 383,997 at the 2020 ...

Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...

. The floodgate is designed to protect the Industrial Canal and the surrounding areas from a

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...

from

Lake Pontchartrain Lake Pontchartrain ( ; ) is an estuary located in southeastern Louisiana in the United States. It covers an area of with an average depth of . Some shipping channels are kept deeper through dredging. It is roughly oval in shape, about from w ...

. It consists of two wide vertical lift gates and a wide sector gate. The building of the floodgate was authorized by

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...

in 2006 and operated in tandem with the Lake Borgne Surge Reduction Barrier to reduce the risk of storm surge damage to some of the

region's most vulnerable areas –

New Orleans East New Orleans East (also referred to as Eastern New Orleans, N.O. East and The East) is the eastern section of New Orleans, Louisiana, a large section of the 9th Ward of New Orleans, mostly not developed until the later 20th century. This collec ...

, metro New Orleans, the

Ninth Ward The Ninth Ward or 9th Ward is a distinctive region of New Orleans, Louisiana, which is located in the easternmost downriver portion of the city. It is geographically the largest of the 17 Wards of New Orleans. On the south, the Ninth Ward is b ...

, Gentilly, and

St. Bernard Parish St. Bernard Parish (; ) is a List of parishes in Louisiana, parish in the U.S. state of Louisiana. The parish seat and largest community is Chalmette, Louisiana, Chalmette. The parish was formed in 1807. St. Bernard Parish is part of the New Or ...

Design

The Seabrook Floodgate Structure consists of a sector gate and two vertical lift gates approximately south of the Senator Ted Hickey Bridge with

flood wall A floodwall is a freestanding, permanent, engineered structure designed to prevent encroachment of floodwaters. Floodwalls are mainly used on locations where space is scarce, such as cities or where building levees or dikes (dykes) would in ...

tie-ins on the east and west sides. Other components of the Seabrook Floodgate project include added T-walls and the replacement of the existing

Alabama Great Southern Railroad The Alabama Great Southern Railroad is a railroad in the U.S. states of Alabama, Georgia (U.S.), Georgia, Louisiana, Mississippi, and Tennessee. It is an operating subsidiary of the Norfolk Southern Corporation (NS), running southwest from Chatt ...

gate with a new taller gate that met the 100 year level of risk reduction; new T-walls that tie into a new vehicle gate built at the

boat launch A slipway, also known as boat ramp or launch or boat deployer, is a ramp on the shore by which ships or boats can be moved to and from the water. They are used for building and repairing ships and boats, and for launching and retrieving small ...

on Leon C. Simon Drive; and raising the Hayne Boulevard ramps on both the east and west sides of the canal. The Seabrook structure closed the only remaining gap on the East Bank of the Hurricane and Storm Damage Risk Reduction System.

Construction

The

US Army Corps of Engineers The United States Army Corps of Engineers (USACE) is the military engineering branch of the United States Army. A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment, military construction, and civil wor ...

awarded the construction of the project to Alberici Constructors, Inc. in July 2009 Construction started in the fall of 2010, and although construction activities continued beyond the Corps' projected June 1, 2011 deadline, a temporary

cofferdam A cofferdam is an enclosure built within a body of water to allow the enclosed area to be pumped out or drained. This pumping creates a dry working environment so that the work can be carried out safely. Cofferdams are commonly used for constru ...

was built to reduce risk to the area during the construction. The floodgate structure opened to marine traffic in August 2012. The same month it was closed for the first time, in order to protect the city from

Hurricane Isaac The name Isaac (or the variant Isaack) has been used for six tropical cyclones in the Atlantic Ocean and for one in the South Pacific Ocean, and has been used for one extratropical european windstorm. In the Atlantic: * Tropical Storm Isaac (1988) ...

. Notable flooding was not seen in the protected area from Category 4

Hurricane Ida Hurricane Ida was a deadly and extremely destructive tropical cyclone in 2021 that became the second-most damaging and intense hurricane to make landfall in the U.S. state of Louisiana on record, behind Hurricane Katrina in 2005. In terms of m ...

in 2021. Water levels on Lake Pontchartrain were slightly lower than

Hurricane Katrina Hurricane Katrina was a powerful, devastating and historic tropical cyclone that caused 1,392 fatalities and damages estimated at $125 billion in late August 2005, particularly in the city of New Orleans and its surrounding area. ...

, but significant -- areas further west of the city, such as LaPlace, were inundated by high waters. Work to increase protection for the areas further west of New Orleans has come to fruition in the West Shore Lake Pontchartrain project, for which construction began in December 2022.

Notes

{{reflist Flood barriers Buildings and structures in New Orleans United States Army Corps of Engineers Flood control in the New Orleans metropolitan area Lake Pontchartrain