When it comes to visibility in the water we need to see down in the water at least a foot, but the more visibility the better. It is not uncommon for us to fish and feel good about 2-3 feet of visibility. The more visibility the better chance the trout have to see your flies. At times there may be less than a foot of visibility, when this occurs it time to find somewhere else to fish.
For leaders, we can generally use a much stronger leader than you normally would. No need worrying about the trout being leader shy. Plus, when the water is high you will inadvertently hook the bottom of the river, debris, and lots of stuff besides fish that you cannot see. You’ll lose less flies with using heavier leaders and tippets, plus when you hook a fish you want to play him as quickly as possible. Being able to put a little more pressure on the trout to hold him in the slower currents or get him away from snags is always a plus.
I am fishing a 9 ft 2x leader with a tippet ring with 16 inches of 3x fluorocarbon to the first fly, then another 12-16 inches of 4x fluorocarbon tippet tied to the bend of the first fly and attaching my second fly. I am attaching two BB split shot above the tippet ring and setting my indicator about 8 ft above my split shot. This is not the easiest setup to cast, but it has been effective. Plus, when you do hang up on something you can break it off without messing up your leader. All you usually need is some more tippet and a few flies.