SECTION 4: RISK ASSESSMENT
The event that occurred in Holly Springs in 2003 defines the potential extent of damages that may occur because of landslide in Wake County. This event caused damages to multiple nearby homes but did not result in any deaths or injuries. Impact: 1 – Minor Spatial Extent: 1 – Negligible Historical Occurrences According to the North Carolina Department of Environmental Quality (NC DEQ), two recent landslides have occurred in Wake County and caused significant property damage. These event narratives from NC DEQ are reported below: Interstate I-540, Wake County (summer 2000) — While landslides are more frequent in the mountainous part of North Carolina, landslides also occur in other parts of the state. One landslide example occurred in the summer of 2000 along Interstate I-540 in Raleigh in Wake County. Holly Springs, Wake County (summer 2003) — Piedmont earth movements have affected homes as well. In May 2003 a soil embankment failure in Holly Springs, Wake County, North Carolina, affected a number of homes. Figure 4.15 shows the location of all past landslide occurrences recorded by NC DEQ since 1995. Past landslide events have all occurred on the western side of the county, which is consistence with the susceptibility and incidence mapping produced by USGS. There have been two events in Raleigh, one in Cary, five in Apex, one in Holly Springs, and two in the unincorporated county. The following event details were recorded in the NC Geological Survey’s movement history records: Cary, 1995 – Movement occurred in winter and spring of 1995 in Cary that appears to be threatening an apartment complex. Southeast Durham, 1996 – A slide caused road damage, blocked a drainage ditch, and damaged a cut slope. I-540 and US-70 were affected. Apex, April 1998 – Evidence of failure seen on September 30, 1999. Failure was possibly associated with Hurricane Floyd. West Raleigh, 1999 – Movement began in the winter of 1999 and caused road damage. Sediment covered Lynn Road. The slope was since stabilized with a gabion wall. Holly Springs, 2003 – Damage caused to three homes in a subdivision. Scarp noted at the homes foundation. Apex, 2006 – Movement occurred during Tropical Storm Alberto, however slow movement was noted by a neighbor approximately 4-6 weeks prior to failure. The damage threatened a retaining wall and a sewer line.
Wake County Multi-Jurisdictional Hazard Mitigation Plan 2019
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