1、1 Storm Categories are based on the Saffir-Simpson Hurricane Scale of 1-5, with Category 4storms having 131-155 mile per hour (mph) winds and a 13- to 18-foot storm surge and Category5 storms having winds exceeding 155 mph and surges above 18 feet.Congressional Research Service? ?The Library of Cong
2、ressCRS Report for CongressReceived through the CRS WebOrder Code RS22238Updated September 8, 2005New Orleans Levees and Floodwalls: Hurricane Damage Protection Nicole T. CarterAnalyst in Environmental PolicyResources, Science, and Industry DivisionSummaryHurricane Katrinas storm surge breached floo
3、dwalls and levees surrounding NewOrleans, causing widespread inundation and significant damage and hampering rescueand recovery efforts. Flooding from precipitation and storm surges flowing over leveesand floodwalls was anticipated because the hurricanes intensity (Category 4) exceededthe structures
4、 design (Category 3); however, structural failure of the floodwalls andconsequent flooding were uncertain. The factors contributing to breaches are the subjectof conjecture and likely will be the subject of investigation. The breaches occurred atthe Lake Pontchartrain and Vicinity Project being cons