Wallace,
Here is my experience on Pool 2(it’s strictly from the confluence north). As the water continues to warm and flow continues to decrease, my trolling speeds usually increased to as much as 3.1mph(gps). I usually start slower than that and experiment until we get consistently bit. I almost exclusively troll upstream, due to the high rate of speed and the flow in this area, when snagged it can cause some major issues if you have two or more rods to contend with, along with a pleasure boat or two, there just isn’t much room to manuever up there. The other option is to just break the crank off and re-tie.
Lures of choice for me, firetiger fat-rap, shallow runner(it’s a bass plug, don’t ask how I discovered trolling it), #5 chartruese shad rap, smallest chartruese wally diver. I bang these plugs on the bottom hard, especially when I’m fishing in the channel. When fishing the rip-rap, I’m still banging them pretty hard, but you have to be carefull of snags(hence trolling upstream). I don’t recall the exact amount of line out, but anywhere from 50 – 75 feet I’m sure, each lure is different and water clarity also plays a factor in this.
My trolling runs start on the Pike Island side of the channel, just above the no wake area. I head uprive past the Hwy 5 bridge, then I switch shores to the rip-rap below Hidden Falls Landing, all the way to the landing, cut across the channel again, follow that rip-rap to Minnehaha creek. If I catch fish anywhere along here, I work that area over pretty good. If the fish aren’t biting here, I head for the middle of the channel, doing S turns all the way up the same trolling run.
Since pool 2 is catch and release only, I’m sure others will chime in also.
Good Luck!!