Good Luck Dan...
Dunville is a hard fish... people catch, but they're also the one's who put their time in there...
try trolling in around 9 feet of water with fat little crankbaits.... perch, firetiger and blue/chrome colors...
i've seen guys anchor really close up to the dam, 5 to 6 feet from it... and jig with jigheads/twister tails...
you'll need an anchor, and stand a high chance of loosing it... fill a couple of empty bleech bottles with sand/rocks
and use that to keep you there, if you have to cut the line, no big loss that way...
again, good luck to you
Cheers
Goran