2004 Denver Annual Meeting (November 7–10, 2004)

Paper No. 12
Presentation Time: 1:30 PM-5:30 PM


SCHMIDT, Emily L., Geological and Environmental Sciences, Hope College, PO Box 9000, 35 East 12th Street, Holland, MI 49422 and DOYLE, Briget C., Geology and Environmental Geosciences, College of Charleston, 66 George St, Charleston, SC 29424, emily.schmidt@hope.edu

Potential flood and debris flow hazards from the failure of a privately-owned and constructed dam in the community of Connestee Falls near Brevard, NC, were mapped and analyzed using the Geographic Information System (GIS) ArcGIS by ESRI. The area near the dam has a history of landslides and heavy rain events. If these phenomena were to occur and impact Ticoa Dam, the small community of Dunn′s Rock would likely be flooded. Dunn′s Rock is located 2.4 km (1.5 mi) downstream and 195 m (640 ft) below the dam. The stream valley would channel the flood waters through Gwynn Valley Camp, a children′s summer camp, located just above Dunn′s Rock. The heavy vegetation on either side of the stream would be caught up in the flow, increasing the volume of material by 150 to 200% before draining into the French Broad River. Between the river and the summer camp are several homes and a roadway that would also be affected by the water and debris. Analysis of the area using ArcGIS has given the probable volumes of water and debris caused by failure of the dam, as well as the maximum discharge through the valley. ArcGIS was also used to determine where the water and debris would be deposited prior to the water draining down the French Broad River toward the city of Brevard. Determining areas of flooding and debris deposition will assist in defining areas to be evacuated as well as emergency evacuation routes should a landslide occur or a storm threaten to overtop the dam. Future research will investigate the potential impact of the failure of other dams in the Connestee Falls community, including Atagahi Dam, which drains into the same valley as Ticoa Dam.