Approximate - nearest available gauge. Use as general reference only.
At 3400 cfs (3200 at Indianford gauge + 200 from Turtle Creek) there are numerous runnable lines down the dam with a few rooster tails that drop into some not too manky holes. (Technically it is illegal to paddle above or down the dam.) Three-fourths of the hydraulic at the bottom of the dam looks either shallow-rocky or just plain keepy.
However, at the far river-right there are 3 holes that provide some fun, all of which are shallow. The 3rd hole from the bank is the best at this level. Its a good balance of retention and swiftness. It allows some nice surfs and endless flatspins, even a few blunts and blasts in just the right spot. The hole also has gentle eddy service and provides a nice eddy line for squirt maneuvers when you wash out.
At flows from 2600-3900 cfs this goes from shallow and retentive (allowing spins and blasts) to nearly sticky (allowing fast spins, blasts, and a few ends). This hole is on the far river right and is accompanied by several other holes that are surfable but shallow. Most holes on the right side are tame until higher levels.
When the water rises above 4300, the entire river right starts looking ugly and sticky, then around 5000 all the way up to 5600 and probably beyond, it all looks like one big death machine. But that is when the usually shallow, and more accessible, river-left side of the dam comes into play (and its good stuff).