Smallscale yellows: There is a decent population of smallscale yellows in the dam and there are some trophy specimens as well. Your best bet to targeting them is at first and last light. The fish will concentrate in the windward bays where insects have collected and you can see them head and tail rising. These fish are extremely difficult to target as you have no idea if they are eating miniscule midges, windblown terrestrials or anything in-between and the fish do not have a defined feeding path so leading a fish is very difficult. It is not impossible and I have landed a couple of good fish with a dry and dropper rig. I like using a terrestrial (hopper or beetle) as the dry and then hang a small generic nymph (GRHE) in #16/18 (must have some flash in it and be dark in colour) 15 -20 cm off the bend of the terrestrial.
If there is sufficient flow at the inlet and you can access it with a boat, this would be your best bet for targeting the yellows. If the visibility is good, you could be in for some sight fishing opportunities. Long line nymphing, with small mayfly and caddis nymphs is the order of the day. Try and keep your flies as natural and small as possible. Larger, flashier flies tend attract the bass, which becomes very frustrating when they jump onto the fly before the yellows have a chance to even see the fly.