The reconstruction of New Orleans refers to the process of rebuilding the city following the failure of levees and floodwalls during Hurricane Katrina on August 29, 2005. The federally built hurricane protection, called the Lake Pontchartrain and Vicinity Hurricane Protection Project failed, resulting in breaches that released tens of billions of gallons of water flooding approximately 80% of the city. The flooding remained in the city for days, in many places for weeks.