I think the line gets really blurry between what's a cascade and what's a waterfall, and there's the "cascading waterfall" bit as well.
I realize almost all, if not all of these are seasonal, and most don't do well in terms of photography. I have a few photos I like, but the weird mustard brown soil and/or limestone stuff just doesn't look pretty in photos. Bamawester on Flickr has a lot better set of photos for some of these, but he managed to get out on a day with a lot of fog.
Alm's house is probably my favorite trail around here, and having the waterfalls there helps for sure. I think the alm's house/fagan springs/ wildflower trail section of the preserve is a very pretty area.
There are other seasonal waterfalls I could mention, at Rainbow Mtn preserve (2), Keel Mtn Preserve (1), and at Blevin's Gap Preserve (1, maybe more), but not quite enough to expand the title of the thread. These are places that I like to go to when I don't feel like driving an hour or longer, or want a quick outing and/or a waterfall fix. I wouldn't call Monte Sano a favorite area of mine, but it's close to home, and I don't think enough people know about these places around here, really. There are also quite a few caves in the area, 3 on Rainbow mtn, not a 10 minute drive from my house. I've run across several on Monte Sano, and then there's the natural well up there that's infamous [haven't seen it yet]. There's video on youtube of people descending down into it.
I'm totally comfortable with calling seasonal waterfalls as waterfalls, so long as they occur every year for more than just a day or two after heavy rain. Generally speaking, most things I'd call a cascade are waterfalls, but I consider a cascade to be a waterfall which lacks a sudden drop, pretty much anything over a 30 degree angle. If it drops at least a few feet in a few feet, I'll probably call it a waterfall. Sudden drops less than 2-3ft, cascades much longer than their drop, and man-made structures are generally not waterfalls in my mind. I call most non-waterfalls rapids, not cascades, but the terms are often interchangable, creating greater confusion.
Bamawester has some great waterfall photos from that area (and everywhere else he goes). He does tend to get up early, as a hunch for foggy conditions, and *wink* uses HDR at least some of the time.
One area I'd really love to hear more about is the outskirts of the Tennessee River Valley, like Pisgah Gorge, as well as the areas in the green triangle of Walls of Jericho and the surrounding WMA. I know people go there, but we hear very little with regard to waterfalls, even though I know of several in the area. But seriously... I like that you did this, and I hope others do the same, even if they don't particularly like the area they are describing. The only way information gets out is if we put it out, since trail guides are almost always under-inclusive. Alabama used to be pretty bad in this respect, but the situation has improved dramatically since I first moved their in 2005, in large measure due to this site. Now I look at other states (Pennsylvania, West Virginia, and Kentucky, I'm talking to you) and am shocked again at how little information is out there. Tennessee isn't that bad, but even here I have trouble finding information about some places. For example, several STATE parks have no page on the DNR site. The same is true in New York, btw. END OF RANT.