Wake County Hazard Mitigation Plan - January 2020


should include the latest research on how the tornado hazard frequency and severity could change. The level of significance of this hazard should be revisited over time.

Vulnerability Assessment People

People and populations exposed to the elements are most vulnerable to tornados. The availability of sheltered locations such as basements, buildings constructed using tornado-resistant materials and methods, and public storm shelters, all reduce the exposure of the population. According to the 2017 American Community Survey (ACS), 12,321 occupied housing units (3.2%) in Wake County are classified as “mobile homes or other types of housing.” Based on an estimated average of 2.62 persons per household from the 2017 ACS, there are approximately 32,281 people in Wake County living in mobile homes. Since 1950, the NCEI records seven fatalities and 213 injuries attributed to tornadoes in Wake County; these fatalities and injuries were the result of tornadoes rated as low as EF0, illustrating the destructive power of tornadoes and the dangers they pose to exposed populations without proper shelter. Property General damages to property are both direct (what the tornado physically destroys) and indirect, which focuses on additional costs, damages and losses attributed to secondary hazards spawned by the tornado, or due to the damages caused by the tornado. Depending on the size of the tornado and its path, a tornado is capable of damaging and eventually destroying almost anything. Construction practices and building codes can help maximize the resistance of the structures to damage. Secondary impacts of tornado damage often result from damage to infrastructure. Downed power and communications transmission lines, coupled with disruptions to transportation, create difficulties in reporting and responding to emergencies. These indirect impacts of a tornado put tremendous strain on a community. In the immediate aftermath, the focus is on emergency services. Since 1950, damaging tornadoes in the County are directly responsible for $370 million worth of damage to property, and no reported damage to crops, according to NCEI data. Table 4.74 through Table 4.78 detail the estimated buildings impacted from tornado events of magnitudes ranging from EF0 to EF4. Note that these tables provide an estimate of building damages should all exposed property be impacted by an event of the stated magnitude. Actual damages resulting from a tornado event of each magnitude would be lower because the event would impact only a fraction of the county.

Wake County Multi-Jurisdictional Hazard Mitigation Plan 2019


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