UC Berkeley

Levee failures during Hurricane Katrina left 85% of New Orleans flooded, 1,500 dead, and about 400,000 homeless. Three separate investigations into the levee failures have been concluded, yet none of these studies conclusively determined why the St Bernard polder flooded so deeply, despite Team Louisiana’s conclusion regarding early failure of the Mississippi River Gulf Outlet (MRGO) levees. Detailed wave and hydrodynamic modeling reported here reveals the cause of extensive breaching of the MRGO levees and how that created a very efficient conduit of surge water into the heart of the city.