I hiked the gorge two weeks ago during my Sheltowee Trace (sort of) thru-hike. ALL streams in the area are LOW, but even at its shallowest , there are still several inches of water in Red River Gorge. My girlfriend and I enjoyed a huge pool a couple of hundred yards southwest of the suspension bridge which was still well over our heads.
The Big South Fork (last week) was another matter entirely, with few places offering water above mid-calf. However, the heavy rains of last night and today may change this.