When the Hydro Plant is offline (as it is through the winter of 2015/16) the whole run is easily navigable down to around 650 cfs (~1ft on the boater's gauge)
The second rapid of note, the Flume, is a class-IV drop that is found below a wavetrain of shallow yet surfable waves (surfing rapid) and also below a difficult (class VI) rapid called Dead Horse that flows into the Housatonic on river right. The drop's namesake is a fairly forgiving chute* of water that falls over a short ledge and is generally run right to left. This drop can be scouted on river right but it probably best scouted while in your warm cloths by hiking a short trail that is across the (non-covered) bridge from the parking area. There is a lookout platform upstream of this drop but it is not an effective view for scouting the drop.
*Forgiving if you hit the flume itself upright. A bad entry means a high speed drop at speed. It shoud go without saying that you should play well within your skills above.
Before the section of flatwater that follows the rapid below the flume, it is worth noting, is a large rock called House Rock. It is an excellent splat rock but use caution since the water beyond the upstream surface of the rock is shallow and squirrly, particularly at lower levels (around 1 foot on the boaters' gauge).