History |
Fact Sheet |
De-Authorization Study |
Navigation Channel Closure |
Ecosystem Restoration Plan Feasibility Study
History of MRGO
The Mississippi River-Gulf Outlet (MRGO) was authorized by a March 29,
1956 Act of Congress (Public Law 84-455) to provide an emergency outlet
from the Mississippi River in the interest of National defense and
general commerce and as a safer and shorter route between the Port of
New Orleans and the Gulf of Mexico. The act authorized construction of
the MRGO Project in accordance with the recommendation of the Chief of
Engineers contained in House Document No. 245, 82nd Congress. Public
Law 84-455 reads in part:
“The existing project for Mississippi River, Baton Rouge to the Gulf of Mexico,
is hereby modified to provide for the Mississippi River-Gulf Outlet to be
prosecuted under the direction of the Secretary of the Army and supervision
of the Chief of Engineers, substantially in accordance with the
Chief of Engineers, contained in House Document Numbered 245,
Eighty-second congress, at an estimated cost of $88,000,000…”
The MRGO extends from the Inner Harbor Navigation Canal (IHNC) to the
38-foot depth contour in the Gulf of Mexico. Construction of the MRGO
channel began in 1958 and was completed in 1968. All reaches of the
MRGO navigation channel were authorized as a 36-foot deep, 500-foot
bottom width waterway with the exception of the Bar Channel in the Gulf
of Mexico which was authorized as a 38-foot deep, 600-foot bottom width
waterway. The channel was dredged through shallow bays, coastal marshes
and cypress swamps.
The Beginning
Ideas for a shorter navigation route to the Gulf of Mexico have been
around for centuries. Corps records indicate a ship canal was proposed
to Congress as far back as 1852. However, it wasn’t until the 1940’s
when Port of New Orleans officials, as well as local and nationally
elected officials, requested that the federal government build a shorter
navigation route from New Orleans to the Gulf of Mexico. These leaders,
along with the state government, envisioned two purposes for the
channel – a safer, more efficient route to the Gulf and economic
development spurred by expanded navigation capabilities in the vicinity
of the new channel.

The vision included expanded port facilities and a new “Centroport,”
a vast import/export complex complete with warehousing, a cargo airport,
and road and rail connections. The Centroport was planned for the area
that is now the north and south shores of Almonaster- Michoud area of
Orleans and St. Bernard Parishes, as well as the area that encompasses
the west side of the MRGO in St. Bernard Parish.
The Louisiana Legislature of 1944 officially empowered the governor “to
aid and assist the federal government in obtaining and completing…. a
tidewater canal from New Orleans to the Gulf on the eastern side of the
Mississippi River. In March of 1958 construction of the channel began
on the reach between the Industrial Canal and Paris Road. By February
of 1960, dredging work was initiated to construct an interim channel of
full depth and only half the width. In July of 1963 the interim channel
was completed and on July 25, 1963 the first vessel traveled down the
channel. By 1968, all dredging was completed on the channel, and it was
operating at full capacity.
Hurricane Katrina
When Hurricane Katrina hit the Gulf Coast in August 2005, the parishes
of Southeast Louisiana and counties of coastal Mississippi suffered
widespread flooding and severe wind damage. Hurricane Katrina caused
shoaling in the MRGO channel which limited its depth to 22 feet, and
thus restricted deep-draft vessel access. Many deep-draft reliant
businesses were severely impacted by storm damages and the limited
navigability on the channel. Some companies chose to relocate while
others were left to decide how to recover. Following Hurricane Katrina,
in June 2006, the US Congress requested a plan for de-authorization of
the MRGO (see Public Law 109-234).
MRGO Deep Draft De-Authorization
Congress directed the Secretary of the Army, acting through the Chief of
Engineers, to plan for de-authorization of the MRGO from the Gulf
Intracoastal Waterway (GIWW) to the Gulf of Mexico. The plan was to be
developed in consultation with St. Bernard Parish, the State of Louisiana,
and affected Federal Agencies. USACE started the de-authorization study
in 2006. The goals of the study were to develop a comprehensive plan to
de-authorize deep–draft navigation, evaluate any navigation functions
that should be maintained, identify measures for hurricane and storm
damage reduction, and to refine the plan to be fully integrated and
consistent with the Louisiana Coastal Protection and Restoration Plan
(LACPR) Final Report to Congress.
As directed by Congress, USACE submitted an interim report in December
2006 highlighting a viable plane to completely close the MRGO to all
navigation from the GIWW to the Gulf. In January 2008 the Chief of
Engineers signed a report recommending de-authorization of the channel,
construction of a closure structure across the channel at Bayou La
Loutre, and development of a supplemental report to provide an ecosystem
restoration plan for the areas affected by the MRGO. On June 5, 2008
the Assistant Secretary of the Army for Civil Works forwarded the Final
MRGO Deep-Draft De-authorization Report to Congress, officially
de-authorizing the MRGO from the GIWW to the Gulf of Mexico as a
federal navigation project.