Waterwolf was correct about the currents of the river during high generation schedules like we're seeing on the Clinch. There is so much water moving down river that rocks and other objects cause "pockets" or other areas of slower moving water. Similar situations happen on smaller rivers during floods.
One thing I've learned over the years is that this much generation doesn't cause harm to the trout. The fishing does tend to be pretty hot after long periods of generation and the fish are pretty feisty.
Sorry for the lame illustration