Can you use an Alabama Rig effectively from the bank with deep water? Say, if fishing from a retaining wall near a dam?

Probably so but I would use braid or at least 20lb test because the odds are against from the bank, likely to get hung up on something with all those hooks.

In Belton you can. By the dam or Leona park.

The most likely snag is a rock.

It helps if you have an idea on how deep the water is. Depth can be judged by throwing a sinker out. Just a plain sinker. Cast it A few times to gauge how deep it is. It'll also give you an idea if any of the huge rocks are in the area. How rough the bottom is.

Once you have a general idea with what you're working with under water. Depth. Then throw your A-Rig. Counting it down to where you think it's a foot or two off the bottom. Don't try to bounce it off the bottom. Because before you know it. A famous Belton lake rock will reach out and grab it. Even with a heavy pound braid, it's a knot that'll snap. Or a bent hook or wire.