Loss Avoidance Study: Hancock, Harrison, and Jackson Counties, MS

Hurricanes Katrina (2005), Gustav (2008), and Isaac (2012) caused major flooding to all three coastal counties in Mississippi. Hancock County was the scene of the final landfall of the eye of Hurricane Katrina, causing total devastation in Waveland, Bay St. Louis, Pearlington, and Clermont Harbor as well as southern Diamondhead. Katrina’s 28-foot storm surge and 55-foot sea waves dragged away almost every structure within ½ mile of the beach in Waveland. The death toll was estimated at about 50. Harrison County was hit particularly hard by Hurricane Katrina and the associated storm surge. Its two largest cities, Biloxi and Gulfport, suffered severe damage and approximately 1,126 fatalities. In Jackson County, the storm surge flowed up the wide river estuary, with the combined surge and freshwater floods cutting the county in half. Over 90 percent of Pascagoula, the easternmost coastal city in Mississippi, and 75 miles (121 km) east of Katrina’s landfall, was flooded from storm surge. Other Jackson County communities, such as Porteaux Bay and Gulf Shores, suffered severe damage, and St. Martin was hard hit; Ocean Springs, Moss Point, Gautier, and Escatawpa also suffered major surge damage.

The flooding associated with Katrina and the wind damage associated with Gustav led many communities to invest in mitigation projects. When Hurricane Isaac hit in 2012, these communities had completed many of their flood and wind hazard mitigation projects. This provided a good opportunity to evaluate the mitigated properties, facilities, and structures and determine the effectiveness of the mitigation projects.

Loss Avoidance Methodology

A primary goal of this study was to evaluate different hazard types and a wide range of mitigation project types funded from a variety of grant sources, both Federal Emergency Management Agency (FEMA) and non-FEMA. To do this FEMA partnered with the State of Mississippi to conduct this Loss Avoidance Study
to evaluate the losses avoided as a result of mitigation projects completed after Hurricane Katrina and before Hurricane Isaac, between August 29, 2005 and August 29, 2012. A map of the project area is shown in Figure 1.

Graphic

In addition to projects funded by FEMA’s HMGP, 406 Mitigation (under Public Assistance), and ICC, this study initially included mitigation projects that were funded by the Small Business Administration, the State’s Elevation Grant Program (administered by the Mississippi Development Authority), and the U.S. Department of Housing and Urban Development; however, the projects were excluded during the screening process because of data limitations.

Acquisition and elevation projects: For these project types, only the three identified storm events were used for the analysis, and all of the structures evaluated were residential. High water mark data was used in the flood inundation analysis. Standard FEMA and the U.S. Army Corps of Engineers data were used to calculate the physical damage and the loss-of-function costs, which included displacement costs (i.e., moving/renting expenses).

Generator projects: For these projects, over 50 individual generators in the three counties were initially screened for evaluation. Twenty-three of the emergency generators were activated as a result of power outage(s) between August 29, 2005 and August 29, 2012, and were included in this study’s analysis. Detailed information on generator facility powering, power outage frequency, outage impacts, and customer base demographics was collected by phone and site visits.

Table 1 shows the losses avoided in 2012 dollars. The last column, Aggregate Loss Ratio, shows the return on investment, based on the project investment (e.g., in the case of acquisition projects, the fair market cost to acquire and demolish the structure). For this study, the Loss Ratio (the ratio of losses avoided to project investment was 1.25 in terms of ratio, which means the projects are cost-effective. The numbers demonstrate that all of the post-Katrina projects are delivering a return on the initial investment that is well in advance of the minimums required to be considered cost-effective.

The mitigation projects completed in Hancock, Harrison, and Jackson Counties after Hurricane Katrina will save residents, businesses, and taxpayers millions of dollars in recovery costs from future disasters.