How a Canal Built to Save New Orleans Nearly Destroyed It | The Why Behind It Ep. 9

How did a canal built to give New Orleans a competitive edge end up becoming one of the most consequential engineering decisions in American history? That's the question at the heart of this episode. The Mississippi River–Gulf Outlet Canal — the MRGO — was authorized by Congress in 1956 and completed in 1968. It was a 76-mile shortcut from the Gulf of Mexico to the Port of New Orleans, designed to compete with the Houston Ship Channel and open the city's inner harbor to deep-draft vessels that could no longer fit through the aging Industrial Canal lock. The economic vision attached to it was vast. Port planners called it Centroport U.S.A. — a wholesale reimagining of how New Orleans operated as a port, built around direct Gulf access rather than the winding Mississippi River. It was ambitious, expensive, and, as things turned out, never realized. By 2005, the MRGO was carrying less than one oceangoing vessel per day while costing roughly $13 million a year to maintain. The canal had also widened from its original 650 feet to nearly 3,000 feet in some locations — not by design, but through decades of bank erosion and saltwater intrusion that killed the surrounding marsh. The wetlands that once buffered the region from Gulf storms had quietly, steadily disappeared. Three months before Hurricane Katrina made landfall, storm surge expert Hassan Mashriqui at LSU's Hurricane Center called the MRGO a "critical and fundamental flaw" in the Corps' hurricane defenses — a funnel that could amplify surge by 20 to 40 percent. His warning was specific, credentialed, and ignored. On August 29, 2005, the funnel performed as warned. Levees along the MRGO and the Intracoastal Waterway breached in approximately 20 places. Post-storm modeling found the canal raised surge heights by roughly three feet and nearly tripled surge velocity in the converging funnel zone. Approximately 80 percent of New Orleans flooded. More than 800,000 people were displaced. In 2009, a federal judge found the Army Corps of Engineers liable for MRGO-related Katrina damage, writing that the failure reflected "insouciance, myopia, and shortsightedness." The canal was closed in 2007. A $2.9 billion restoration plan was drawn up — and never funded, stalled in a dispute over who should pay. This is a story about the long gap between what we know and what we do. --- Sources & further reading [Mississippi River–Gulf Outlet Canal — Wikipedia](https://en.wikipedia.org/wiki/Mississ...) [Hurricane Katrina — Wikipedia](https://en.wikipedia.org/wiki/Hurrica...) [Effects of Hurricane Katrina in New Orleans — Wikipedia](https://en.wikipedia.org/wiki/Effects...) [Effects of Hurricane Katrina in the Southeastern United States — Wikipedia](https://en.wikipedia.org/wiki/Effects...) [Industrial Canal — Wikipedia](https://en.wikipedia.org/wiki/Industr...) [Industrial Canal Lock — Wikipedia](https://en.wikipedia.org/wiki/Industr...) [Jefferson Seaway — Wikipedia](https://en.wikipedia.org/wiki/Jeffers...) [U.S. Army Corps of Engineers civil works controversies — Wikipedia](https://en.wikipedia.org/wiki/U.S._Ar...) [Orleans Levee Board — Wikipedia](https://en.wikipedia.org/wiki/Orleans...) [Timeline of Hurricane Katrina — Wikipedia](https://en.wikipedia.org/wiki/Timelin...) [National Weather Service bulletin for Hurricane Katrina — Wikipedia](https://en.wikipedia.org/wiki/Nationa...) [Lake Borgne — Wikipedia](https://en.wikipedia.org/wiki/Lake_Bo...) [Walter Maestri — Wikipedia](https://en.wikipedia.org/wiki/Walter_...)