HIGH WATER MARK RECONNAISSANCE DATA COLLECTED IN THE AFTERMATH OF HURRICANE KATRINA

Hurricane Katrina (23-30 August 2005) was the costliest natural disaster in US history. It struck low-lying coastlines particularly vulnerable to storm surge flooding. Due to the lack of appropriate instrumentation, field reconnaissance was done in the months following Katrina to collect high water mark data. Maximum storm surges, overland flow depths, and inundation distances were measured along the Gulf Coast of Florida, Alabama, Mississippi and Louisiana. The storm tide peaked to the East of Katrina's path as high as 10 meters in a few locations along the Mississippi coastline. Even along the hardest hit coastline, buildings designed to resist peak hurricane winds were only marginally damaged on upper floors, while walls were blown out on the lower floors. The storm tide measurements along New Orleans's Lake shore indicate that the 17th Street Canal levee failed prior to overtopping. High water mark data is important in preventing future human life and economical losses. While Hurricane Katrina made landfall as a Category 3, the size of the storm created storm surges higher than that of Hurricane Camille (1969, Category 5 at landfall) at all locations. The storm surge increase is attributed to Hurricane Katrina's massive size and the land loss on the barrier islands resulting in an increased vulnerability of the US Gulf Coast to future hurricane storm tides.