Flood Cleanup in New Orleans, LA

Flood cleanup in New Orleans operates under conditions unlike any other American city — below-sea-level topography means that floodwater does not naturally drain and must be pumped out mechanically, and the city's complex drainage system of canals, pump stations, and retention basins must all function simultaneously for flood cleanup to be possible. Hurricane Katrina's August 2005 flooding remains the defining event: the failure of the 17th Street Canal, London Avenue Canal, and Industrial Canal floodwalls allowed Lake Pontchartrain and the Mississippi River Gulf Outlet to inundate 80% of the city for three weeks. The cleanup effort that followed was the largest urban flood remediation in American history, involving the removal of millions of tons of contaminated debris, mud, and toxic materials from over 100,000 flooded structures. The Sewerage and Water Board's drainage pump system — now substantially upgraded post-Katrina — still experiences failures during intense localized rainfall events, causing flash flooding throughout the city even without hurricane conditions.