Sorry for bringing up old posts, but just thought I'd share some recent experience.
Fishing was quite exciting down in the spillway in the 2013 season. Seemed like whenever I was down there, I was catching multiple 15+" largemouth. I actually pulled a striped bass out of there as well, which boggled my mind. I'll have to dig out the picture, it's somewhere. I've caught a couple small crappies on small rapala cranks, but mainly stuck to texas rigged (minus bullet weight) plastic worms casted parallel to shore. I would not recommend casting and retrieving a worm or lure on the bottom, endless amounts of concrete structure to get stuck on. I've lost countless lures in it.
I haven't even bothered continuing in 2014. I was out a dozen times or so, early in the season, and there was absolutely nothing. The fish I did catch were small <10" and they were in very few and far between. Given the harsh winter and the low depth, I'm thinking many of the larger fish died off. May have to stay away for the next couple of years until the population can regrow.