Mississippi River–Gulf Outlet Canal

The Mississippi River – Gulf Outlet Canal (abbreviated as MRGO or MR-GO) is a 76 mi (122 km) channel constructed by the United States Army Corps of Engineers at the direction of Congress in the mid-20th century that provided a shorter route between the Gulf of Mexico and New Orleans' inner harbor Industrial Canal via the Intracoastal Waterway. In 2005, although disputed by the Corps of Engineers, the MRGO channeled Hurricane Katrina's storm surge into the heart of Greater New Orleans, 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 east of I-510's crossing of the Gulf Intracoastal Waterway in New Orleans East and takes a path SSE through St. Bernard Parish wetlands just west of Lake Borgne 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.

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 felt increasingly disadvantaged by the length of time oceangoing vessels needed to navigate the twists and turns of the Mississippi River 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, in particular, came into being as a consequence of the completion of the Houston Ship Channel in 1914. New Orleans' initial response debuted in 1923, with the inauguration of the Industrial Canal linking the Mississippi River and Lake Pontchartrain, thereby creating the Lower 9th Ward and New Orleans East. In a matter of decades, the rapid growth of average ship size in the 20th century rendered the canal locks 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 in the Rivers and Harbors Act of 1956. Construction was completed in 1965.

...
Wikipedia