Wake County Hazard Mitigation Plan - January 2020

SECTION 4: RISK ASSESSMENT

Hurricane Fran (1996) – In the RAH county warning area along, the damage exceeded 2 billion dollars. Damage to crops, livestock, farm equipment/buildings was over 400 million. The agricultural damage was the greatest in Sampson, Johnston, and Wayne counties. Several hundred thousand trees were uprooted or broken. Tens of thousands of homes were damaged by falling trees. In the path of the storm's center, almost every neighborhood was affected. The copious rainfall produced many severe flash and river floods. Along the Crabtree Creek in Raleigh, which crested at its highest since 1973, hundreds of new cars from local dealerships floated in 6 feet of water. Scores of businesses reported heavy damage at the area's largest shopping center. Hurricane Dennis (1999) – The remnants of Dennis finally moved inland across the central portion of the state. Its main impact was to end the drought in the eastern half of the state. The Triangle received from 6 to 8 inches of rain with Chapel Hill peaking out at 12 inches. The I-40 corridor of counties also got dumped on with totals in the 6- to 10-inch range. This water caused considerable urban and lowland flooding. Several main stem rivers also went into flood. The winds with the remnants of Dennis were generally not a significant problem. There were many old, larger trees uprooted and widespread limb damage was reported. However, the wind and rain combination caused considerable crop damage. Hurricane Floyd (1999) – Hurricane Floyd produced more human misery and environmental impact in North Carolina than any disaster in memory. The 15-20 inches of rain that fell across the eastern half of the state caused every river and stream to flood. Many rivers set new flood records. Whole communities were underwater for days, even weeks in some areas. Thousands of homes were lost. Crop damage was extensive. The infrastructure of the eastern counties, mainly roads, bridges, water plants, etc., was heavily damaged. By the end of 1999, $1.5 billion had already been spent, with estimates that the cost would reach $3-4 billion. The counties within the Raleigh county warning area probably sustained more than half of the state total. Even worse, was the loss of life, mainly due to flooding. Many Carolinians did not heed the call to evacuate and many more drove into flooded streams and rivers. In the central part of the state, 21 people lost their lives. Also, the loss of livestock was significant, mainly swine and poultry. Tropical Storm Ernesto (2006) – Tropical Storm Ernesto produced high winds county wide. There were numerous reports form emergency officials of downed trees and large tree limbs. Tropical Storm Hermine (2016) – Tropical Storm Hermine produced heavy rain across portions of central North Carolina. However, due to dry antecedent conditions, no flooding occurred despite rainfall amounts of up to 3 to 5 inches across southeastern portions of central North Carolina. Given the rain and gusty winds associated with Hermine there were numerous reports of trees down and wind damage and resultant power outages. A large tree fell through the roof of a house near New Hill.

Probability of Future Occurrence Probability: 3 – Likely

In the 22-year period from 1996 through 2017, 8 hurricanes and tropical storms have impacted the Wake County area, which equates to a 36 percent annual probability of hurricane winds impacting the county. This probability does not account for impacts from hurricane rains, which may also be severe. An additional 5 storms passed within 50 miles of Wake County during this period; these storms did not have significant wind impacts but may have brought heavy rains. Overall, the probability of a hurricane or tropical storm impacting Wake County is likely. Climate Change One of the primary factors contributing to the origin and growth of tropical storm and hurricanes systems is water temperature. Per the Fourth National Climate Assessment, “ There is growing evidence that the tropics have expanded poleward by about 70 to 200 miles in each hemisphere since satellite

Wake County Multi-Jurisdictional Hazard Mitigation Plan 2019

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