This year marks the 20th anniversary of Hurricane Katrina (August 2005), one of the most devastating hurricane events on record, and a storm that caused significant damage from storm surge.
Much of the damage associated with hurricanes is related to the high winds during the storm. However, the most notable hurricane damage often occurs in areas affected by flooding. Flooding of a building exposes materials to flood waters, often for extended periods of time. With the potential for further damage from the force of impacting waves and riverine flow of flood waters, storm surge flooding can be devastating for a building.
Nelson has investigated thousands of properties for damage associated with hurricanes, including many that were exposed to storm surge flooding. Figure 1 is from a structure in Biloxi, Mississippi after Hurricane Katrina. This structure was not only flooded but was also impacted by wave forces that displaced some exterior walls from the foundation.
Figure 1. Water damage from storm surge flooding in Biloxi, MS after Hurricane Katrina.
Figures 2 and 3 show a medical office in Moss Point, Mississippi that was flooded with more than 6 feet of water during Hurricane Katrina. This structure did not experience any significant wave forces, but the flooding caused damage to the building materials and to the contents and the (expensive) medical equipment throughout.
Figure 2. Structure in Moss Point, MS that was flooded due to storm surge during Hurricane Katrina.
Figure 3. Waterline measured more than 6′ above the foundation at the structure shown in Figure 2.
Hurricane Ike (2008) also caused significant storm surge flooding. Figure 4 shows a coastal home in Crystal Beach, Texas that was impacted by storm surge flooding and wave action forces, causing foundation damage and additional damage to the floor framing and to the siding.
Figure 4. Framing and siding damage to a coastal home from storm surge and wave action from Hurricane Ike.
Hurricane Ian (2022) made landfall near Fort Myers, Florida, with storm surge flooding levels of up to 15 feet above ground in Fort Myers Beach. The extent of inland flooding varies with the typography of the area, including the presence of waterways connected to the ocean. While the building shown in Figure 5 was well inland, about 2.4 miles from shore, this area was still affected by flooding from the storm surge. Despite the fact that remediation work had been performed by the time of Nelson’s investigation, isolated waterlines were still present and showed that the flood waters were at least 28″ above the level of the finished floor of the building. This example highlights not only the devastating and widespread potential nature of such flooding, but also illustrates the need for thorough investigation when visiting a site to document remaining flood evidence, even after remediation.
Figure 5. Waterline on an interior door of a building in Fort Myers, Florida from storm surge flooding during Hurricane Ian.
