Why did so much water flow to Chimney Rock during the Helene flood?

The nearly complete destruction of Chimney Rock Village during the Helene flood was just one shocking aspect of the storm's effects on southern Appalachia. The intensity of the flooding at Chimney Rock was a result of rainfall patterns that were influenced by mountain topography and the "funneling" of the rain runoff into the narrow Hickory Nut Gorge. This video shows what the landscape around Chimney Rock looks like and how the mountains forced extreme rainfall to concentrate in areas that drained to the Rocky Broad River and out of the Hickorynut Gorge past Chimney Rock. The Rocky Broad River has an unusually large drainage area for a stream flowing through such a narrow gorge. This is a product of its unique geology history, which is illustrated with a Microsoft Paint diagram. This video also shows relative locations of other places devastated by flooding to give a sense of where many affected locations are located with respect to one another.