The Mississippi River–Gulf Outlet Canal (abbreviated as MRGO or MR-GO) is a channel constructed by the

United States Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

at the direction of Congress in the mid-20th century that provided a shorter route between the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

and

New Orleans New Orleans ( , ,New Orleans

' inner harbor

Industrial Canal The Industrial Canal is a 5.5 mile (9 km) waterway in New Orleans, Louisiana, United States. The waterway's proper name, as used by the U.S. Army Corps of Engineers and on NOAA nautical charts, is Inner Harbor Navigation Canal ( IHNC). ...

via the

Intracoastal Waterway The Intracoastal Waterway (ICW) is a inland waterway along the Atlantic and Gulf of Mexico coasts of the United States, running from Massachusetts southward along the Atlantic Seaboard and around the southern tip of Florida, then following t ...

. In 2005, the MRGO channeled Hurricane Katrina's storm surge into the heart of

Greater New Orleans The New Orleans metropolitan area, designated the New Orleans–Metairie metropolitan statistical area by the U.S. Office of Management and Budget, or simply Greater New Orleans (french: Grande Nouvelle-Orléans, es, Gran Nueva Orleans), is a me ...

, contributing significantly to the subsequent multiple engineering failures experienced by the region's hurricane protection network. In the aftermath the channel was closed. A permanent storm surge barrier was constructed in the MRGO in 2009, and the channel has been closed to maritime shipping. The MRGO begins just west of I-510's crossing of the

Gulf Intracoastal Waterway The Gulf Intracoastal Waterway is the portion of the Intracoastal Waterway located along the Gulf Coast of the United States. It is a navigable inland waterway running approximately from Carrabelle, Florida, to Brownsville, Texas. The waterwa ...

New Orleans East New Orleans East is the eastern section of New Orleans, the newest section of the city. It is bounded by the Industrial Canal, the Intracoastal Waterway and Lake Pontchartrain. Developed extensively from the 1950s onward, its numerous residential ...

and takes a path SSE through St. Bernard Parish wetlands just west of

Lake Borgne Lake Borgne (french: Lac Borgne, es, Lago Borgne) is a lagoon of the Gulf of Mexico in southeastern Louisiana. Although early maps show it as a lake surrounded by land, coastal erosion has made it an arm of the Gulf of Mexico. Its name comes fro ...

to the Gulf of Mexico near Gardner Island. Much criticized for its negative environmental effects, such as saltwater intrusion, wetlands erosion and storm surge amplification during Hurricane Katrina, the MRGO was closed in 2009. Maritime traffic was barred on April 22, 2009.

History

Conceptually, the MRGO was first envisioned early in the 20th century as a way to provide shipping with a shorter route to the Gulf of Mexico. The

Port of New Orleans The Port of New Orleans is an embarkation port for cruise passengers. It is also Louisiana’s only international container port. The port generates $100 million in revenue annually through its four lines of business – cargo (46%), rail (31%) ...

felt increasingly disadvantaged by the length of time oceangoing vessels needed to navigate the twists and turns of the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it fl ...

from the Gulf to the port's wharfs, versus the much closer proximity to open water offered by its emerging competitors. The modern

Port of Houston The Port of Houston is one of the world's largest ports and serves the metropolitan area of Houston, Texas. The port is a 50-mile-long complex of diversified public and private facilities located a few hours' sailing time from the Gulf of Mexico. ...

, in particular, came into being as a consequence of the completion of the

Houston Ship Channel The Houston Ship Channel, in Houston, Texas, is part of the Port of Houston, one of the busiest seaports in the world. The channel is the conduit for ocean-going vessels between Houston-area terminals and the Gulf of Mexico, and it serves an in ...

in 1914. New Orleans' initial response debuted in 1923, with the inauguration of the

linking the Mississippi River and

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 wes ...

, thereby creating the

Lower 9th Ward The Lower Ninth Ward is a neighborhood in the city of New Orleans, Louisiana. As the name implies, it is part of the 9th Ward of New Orleans. The Lower Ninth Ward is often thought of as the entire area within New Orleans downriver of the Industri ...

and

. In 1943, the proposed project was initially presented to the U.S. Army Corps of Engineers by the Dock Board of New Orleans under the name "Alexander Seaway", in reference to Col. Lester F. Alexander, a member of the Dock Board who was one of the architects behind the New Orleans plan. A competing plan was also presented by Jefferson Parish, referred to as the "Arrow to the Americas,' also known as the Jefferson Seaway. In a matter of decades, the rapid growth of average ship size in the 20th century rendered the

canal locks A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water lev ...

connecting the Industrial Canal to the Mississippi River obsolete; the MRGO as promoted in the 1950s was to help rectify this deficiency by permitting deep-draft vessels to access the Industrial Canal inner harbor. Authorization for the MRGO was formally provided by the

United States Congress The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washing ...

in the

Rivers and Harbors Act Rivers and Harbors Act may refer to one of many pieces of legislation and appropriations passed by the United States Congress since the first such legislation in 1824. At that time Congress appropriated $75,000 to improve navigation on the Ohio and ...

of 1956. Construction was completed in 1968. Due to rapid

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ...

of the surrounding marsh, the canal was already as much as four times wider by 2005 than as originally constructed. When MRGO was built, the channel was wide at the surface. By 2005 the channel had opened to up to 3,000 feet in some locations and had been dredged annually.

MRGO's operational performance

With the completion of MRGO in 1965, the

advanced a plan to largely abandon its wharfs along the Mississippi River and relocate its activities to the inner harbor created by the Industrial Canal, the Intracoastal Waterway, and the MRGO. This vast project, termed Centroport U.S.A., never secured sufficient funding and was quietly jettisoned by the port in the mid-1980s. The France Road Container Terminal and the Jourdan Road Wharf were the only two elements realized according to the Centroport plan. After the abandonment of the Centroport project, the Port of New Orleans refocused its efforts on improving its infrastructure along the Mississippi River, and what little maritime traffic the MRGO hosted progressively dwindled, opening it up to withering critiques. In 1997, the

Competitive Enterprise Institute The Competitive Enterprise Institute (CEI) is a non-profit libertarian think tank founded by the political writer Fred L. Smith Jr. on March 9, 1984, in Washington, D.C., to advance principles of limited government, free enterprise, and individ ...

, a libertarian organization dedicated to "the principles of free enterprise and limited government" attacked it on economic grounds:

The promised economic development along the 76 mile channel in poverty-stricken St. Bernard Parish has yet to materialize. What the MRGO has delivered is an $8-plus million yearly maintenance plan for commercial and recreational waterborne traffic. The nearly $1 billion price tag for the less than two large container ships a day that use the channel is baffling, especially considering that the channel only shaved 37 miles off the original route.

Prior to Hurricane Katrina, environmentalists and others, including voters in St. Bernard Parish whom the canal was intended to help, called for its closure. Criticism intensified following the hurricane, when engineers implicated the MRGO in the failure of levees and flood-walls protecting large parts of

. MRGO was derisively termed a "Hurricane Highway" in Katrina's wake, due to its apparent role in amplifying the impacts of storm surges. According to a congressional hearing statement made in late 2005 by Scott Faber of the Environmental Defense Fund, "Traffic on the MR-GO has fallen by more than 50 percent since 1986. Today, less than one oceangoing vessel per day, on average, uses this man-made short cut, which costs approximately $13 million annually to maintain. Like many waterways constructed by the Corps, the MR-GO failed to attract as much traffic as the Corps predicted when the project was constructed."

Role in Hurricane Katrina disaster

Levees along the MRGO and the Intracoastal Waterway were breached in approximately 20 places, directly flooding most of St. Bernard Parish and

. Storm surge from the MRGO is also a leading suspect in the three breaches of floodwalls along the

. Three months before Katrina, Hassan Mashriqui, a storm surge expert at

Louisiana State University Louisiana State University (officially Louisiana State University and Agricultural and Mechanical College, commonly referred to as LSU) is a public land-grant research university in Baton Rouge, Louisiana. The university was founded in 1860 nea ...

's Hurricane Center, called MRGO a "critical and fundamental flaw" in the Corps' hurricane defenses, a "

Trojan Horse The Trojan Horse was a wooden horse said to have been used by the Greeks during the Trojan War to enter the city of Troy and win the war. The Trojan Horse is not mentioned in Homer's ''Iliad'', with the poem ending before the war is concluded, ...

" that could amplify storm surges 20 to 40 percent. Following the storm, an engineering investigation and computer modeling showed that the outlet intensified the initial surge by 20 percent, raised the height of the wall of water about three feet, and increased the velocity of the surge from to in the funnel-shaped region between the converging MRGO and Gulf Intracoastal Waterway. Mashriqui believes this funnel effect contributed to the scouring that undermined the levees and floodwalls along the Gulf Outlet, the Intracoastal Waterway, and the Industrial Canal. "Without MRGO, the flooding would have been much less," he said. "The levees might have eenovertopped, but they wouldn't have been washed away." The Army Corps of Engineers disputes this causality and maintains Katrina would have overwhelmed the levees with or without the contributing effect of MRGO since the storm surge was perpendicular to the length of the canal. Katrina's passage caused extensive shoaling of the MRGO, resulting in its impassability for deep-draft oceangoing vessels. Officials of St. Bernard Parish immediately opposed its reopening. Maritime interests called for re-opening the Gulf Outlet but equipping it with protective floodgates, or accelerating construction of the Inner Harbor Navigational Canal lock project, which when completed would allow MRGO to be closed without affecting deep-draft commercial traffic.

Closure

In May 2007 the Corps of Engineers announced it would close the MRGO to all traffic and would build an earthen dam across the MRGO in alignment with the natural ridge paralleling Bayou La Loutre. The Bayou La Loutre ridge siting was selected to complement future wetland restoration efforts, as the natural ridge could regain its historic function of sheltering the marsh and swamp behind from the Gulf of Mexico. Construction began in late 2008, and the Corps of Engineers completed the closure structure across the MRGO at Bayou La Loutre in July 2009. Supplementing construction of the closure, the Army Corps of Engineers also produced th
MRGO Ecosystem Restoration Plan
The plan outline key components of revitalizing the wetlands and water bodies that had been damaged by the construction and resulting factors (e.g. salt water intrusion) of the MRGO. The roughly $2.9 billion plan included: * A freshwater diversion at or near Violet, Louisiana * 14,123 acres of fresh and intermediate marsh * 32,511 acres of

brackish marsh Brackish marshes develop from salt marshes where a significant freshwater influx dilutes the seawater to brackish levels of salinity. This commonly happens upstream from salt marshes by estuaries of coastal rivers or near the mouths of coastal riv ...

* 10,318 acres of cypress swamp * 466 acres of saline marsh * 54 acres of Bayou La Loutre ridge habitat * 71 miles of shoreline protection in Lake Borgne, along the MRGO, and in the Biloxi Marsh, including 5.8 miles of oyster reef restoration in the Biloxi Marsh * 2 recreation featuresMRGO Ecosystem Restoration Plan by USACE
The MRGO Ecosystem Restoration Plan was never implemented due to a disagreement about funding. The U.S. Army Corps of Engineers' District Engineer stated "I further recommend Federal and Non-Federal Sponsor responsibilities and cost sharing requirements...," while the State of Louisiana viewed the "project should be undertaken at full Federal expense and that the state should have no financial obligations with respect to the Mississippi River Gulf Outlet Ecosystem Restoration Project."

Surge Barrier

Closer to New Orleans, a robust 1.8 mile surge barrier costing more than $1 billion was constructed. The surge barrier closed the narrow end of the "funnel" described by the convergence of the levees bounding the northern edge of the

and the southern edge of the MRGO, preventing future storm surges from penetrating into the inner harbor of the Industrial Canal and Intracoastal Waterway. Two gates were built, one at Bayou Bienvenue and another across the Intracoastal Waterway, to permit the passage of barge and other small commercial traffic during normal weather conditions. The barrier, the largest of its kind in the United States, should protect against storm surges up to 28 feet in height. It was finished in 2011, and is far more significant than the Bayou La Loutre closure structure. It is two feet lower than the levees it will connect to in New Orleans East and St. Bernard Parish. This will allow water to spill over the control structure before it overtops these levees.''Surge barrier spells death knell for MR-GO'', The Times-Picayune, October 22, 2009.

Notes

External links

Army Corps liable for Katrina damage, US court finds
''Christian Science Monitor'' November 19, 2009

''Washington Post'', Wednesday, September 14, 2005
Port of New Orleans
{{DEFAULTSORT:Mississippi River - Gulf Outlet Canal Canals in New Orleans Canals in Saint Bernard Parish History of New Orleans Intracoastal Waterway Flood control in the New Orleans metropolitan area Canals opened in 1965 1965 establishments in Louisiana