TOP: A man looks over debris from a Baptist church in Gulfport, Miss. BOTTOM: Hurricane Katrina's winds 

 storm surge tossed fishing boats ashore like toys, grounding them in Plaquemine Parish, La. 



and 



or "SLOSH" and prepared by the National 

 Ocean & Atmospheric Administration and 

 the U.S. Army Corps of Engineers for coastal 

 sections. 



The model predicts the worst-case storm 

 surge from an array of hurricane tracks for 

 each hurricane category. 



Rogers then combined the results of the 

 study grids and plotted the peak water levels 

 along the "first developed shoreline from 

 Texas to Tampa Bay." 



"For most of the Mississippi coast, the 

 storm surge for each hurricane category is 

 roughly twice as high as is typical for other 

 areas along the Gulf and Atlantic coast," he 

 says. 



Although Katrina weakened to a 

 Category 3 before making landfall, experts 

 estimate the surge to have maintained a level 

 associated with a Category 5 hurricane. The 

 surge did not dissipate as rapidly as the wind 

 speed, says Rogers. 



"Katrina came into the Mississippi Gulf 

 Coast on the worst possible track for a high 

 storm surge," he says. "The shallow depth of 

 the offshore shelf in the Gulf of Mexico, as 

 well as the bay-like shape of the shoreline, 

 contributed to the high surge." 



"It is therefore no accident that Camille 

 and Katrina set records in the same area," 

 Rogers adds. Another hot spot is the Big 

 Bend area of Florida that stretches from 

 Bayonet Point through Homosassa Springs 

 and the Crystal River to Steinhatchee. 



New Report 



The FEMA MAT report makes 

 numerous flood recommendations, 

 including establishing flood levels 

 in the building codes that exceed the 

 current base-flood elevation. 



The federal agency also 

 encourages communities to review 

 storm surge data and conduct a revised 

 tide frequency analysis. For rebuilding 

 efforts, it encourages local officials to 

 use the Katrina Flood Recovery Maps 

 until the new flood maps are released. 



The base-flood elevations were 

 established to expedite the rebuilding 

 process of hard-hit areas in Louisiana 

 and Mississippi. 



"Although FEMA cannot require 

 communities to adopt the Advisory 

 Flood Elevations, continued use of 

 the flood data on the current Flood 

 Insurance Rate Maps could result in 

 residential and commercial buildings 

 that will be vulnerable to flood 

 damage," the report says. 



The buildings in Mississippi and 

 Louisiana were not built high enough or do 

 not have the structural integrity to resist flood 

 forces that may be encountered in future 

 large events, m 



To find out more about the FEMA MAT 

 report on Hurricane Katrina, visit the Web: 

 vvww.fema.gov/rebuild/mat/mat_repts.shtm 

 and click on "New MAT Reports. " 



Coastwatch I Autumn 2006 I www.ncseagrant.org 1 1 



