What we've found here in central Iowa, is that starting about the last week in August, and running right up through at least the end of October, white bass and hybrids tend to inhabit the shallows very frequently. In the reservoirs here, they are following the shad, and can often be caught in water less than 3' deep, and sometimes literally inches from shore.
A fast moving shad imitator or large topwater popper (like a crease fly or pencil popper) can elicit some pretty exciting strikes.

We've also found that the hybrids have a tendency to try to exit the lake over (or through) the outlet structure, so if your lakes have fair-sized streams below them, you might consider targeting them.

Good luck!!