You might give some traditional feather wing low water flies tied on size 4 or 6 low water hooks a try. Remember that these are only tied so that the whole fly incluing the tail covers no more than 1/2 the shank of the hook. I would try the silver blue, claret adler, or kelson's sun fly.
Also, I have found that small, size 8 or samller flies tied in the style of the Irish shrimp flies flies work reasonably well. I'm speaking of flies like the moise grub, Headley's secret weapon, etc. Another thing that works in the faster water is a small Ally's Shrimp (size 8 to 12) or black Ally's Shrimp. You can also simply use a small hook (8 to 10) and tie on pearl flashabou for a tail, a tinsel body, and a magenta, blue, or purple hackle. The hooks I refer to are all up eye salmon irons.
Ryan's suggestion of a spade is also a good one. I prefer to fish it in a smaller size when the fish don't seem to want to move for a fly and others are getting fish with spinners, etc.