"On 29 August 2012, Hurricane Isaac made landfall along and impacted the Louisiana and Mississippi coastline. Impacts to the coastal Louisiana area, including New Orleans and surrounding communities, were considerable. The 2012 greater New Orleans area 100-year Hurricane and Storm Damage Risk Reduction System (100-year HSDRRS) performed to expectations in preventing the Hurricane Isaac storm surge from inundating the areas within the system. However, substantial flooding did occur in areas without federal levee systems, including, but not limited to Slidell, Mandeville, Madisonville, LaPlace, Braithwaite, Lafitte and others. During the design of the 100-year HSDRRS, multiple sensitivity analyses were conducted to describe the potential effects of the system on storm surge elevations outside of the system. These modeling efforts predicted that the 100-year HSDRRS would increase the estimated peak water levels generally less than 0.2 feet in communities outside the HSDRRS. However, in response to the substantial flooding outside of the HSDRRS, concerns were raised regarding the effects of the 100-year HSDRRS during Hurricane Isaac on areas outside the system. Local and state officials requested an analysis to assess the effect of the 100-year HSDRRS on certain areas outside the system as a result of Hurricane Isaac. The analyses contained in this assessment were conducted by a team consisting of personnel from the U.S. Army Corps of Engineers' New Orleans District, Mississippi Valley Division, and Engineering Research and Development Center, and the National Oceanic and Atmospheric Administration's National Weather Service. Data were compiled from the Corps of Engineers New Orleans District, the National Oceanic and Atmospheric Administration's National Hurricane Center, National Weather Service River Forecast Center in Slidell, LA, National Data Buoy Center, and National Ocean Service, the United States Geological Survey, and the State of Louisiana."
U.S. Army Corps of Engineers, Team New Orleans: http://www.mvn.usace.army.mil/