Mississippi River–Gulf Outlet Canal

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.

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.

[8] Criticism intensified following the hurricane, when engineers implicated the MRGO in the failure of levees and flood-walls protecting large parts of Greater New Orleans.

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.

"[9] Levees along the MRGO and the Intracoastal Waterway were breached in approximately 20 places, directly flooding most of St. Bernard Parish and New Orleans East.

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.

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.

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.

Construction began in late 2008, and the Corps of Engineers completed the closure structure across the MRGO at Bayou La Loutre in July 2009.

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.