You've been given some good advice here in regard to how to alter the presentation of the spinner. As was suggested, some spinners are better suited for different current speeds, different depths, and different ways of presenting the spinner.
My experience is that in fast, shallow water, the size 3 spinner that is weighted fairly lightly is the easiest lure to get to swim through without hanging up all the time. Related to that issue, hanging up, there's one thing that leads to a lot of hang-ups for novice and intermediate spinner fishermen ,and that is this huge, new reliance on ultra-thin diameter braided lines; MOST common spinner weighting patterns were developed before braided line was invented, and many traditional spinner weights are too high for fishing shallow water on line that is the diameter of 6- or 8-lb test monofilament.
In shallower water, I prefer to have a spinner that will "swim", on its own, based on the amount of line drag created by a monofilament line of about .014" diameter (which will be a 12- to 15-pound test lien, depending on the maker of the line). There's this idea that thinner line is "better", when in reality, in shallow, fast water, thinner line is actually worse on many types of casts, like upstream at steep angles, and so on.
Use a spinning reel, and have a regular-diameter monofilament line, but also have a THICKER-diameter monofilament spool with you, one which will "swim" the lure, so you get a longer, slower presentation. I can guarantee you that unless you are a really bonafide expert spinner fisherman, that you will find it much easier to fish shallow, fast water with a .014 to .017 diameter line, especially when casting upstream, and allowing the current's movement on the line to "swim" the spinner downriver. Shallow, fast water is also a situation when it is not so necessary to adhere to the "low and slow" rule--a LOT of fish can be taken a foot under the surface with the right spinner for the conditions. In three feet of water, a foot deep is ample if the fish are negotiable and the lure does not spook them by being ridiculously too-bright and reflective.
Try a #2 or #3 that is **lightly** weighted in shallow, fast water. If you find yourself "reeling the spinner in" to make it spin OR to keep it from hanging up, the line is too thin and/or the spinner is too heavily-weighted for the conditions, or both. My ideal idea is a #3 that will "swim", not "thump through" a shallow area, swimming on its own, with the very minimal amount of retrieve, the retrieve being nothing more than gathering up loose line as the spinner gets closer to my position when it had been cast upstream. On cross-stream and quartering-down casts, the force of the current will mean that no retrieve is needed--and in fact the opposite, letting out line in small amounts, frequently, will often be needed.
For years I carried three spools: standard, thicker, and thick line. This is the main advantage of spinning reels: the ability to change the line to IMPROVE the performance of a fixed weight spinner for different conditions. Once braided line became so common, but spinner body and blade weights stayed the same, I think it set the stage for many beginning and intermediate spinner fishermen being sort of set up for difficulty in shallower water scenarios.
Again though...this thread is trying to condense something tricky into a couple hundred words per fisherman. My advice: get into the .014" to .016" line diameter general area, present mostly upstream, or quartering upstream, and approach this more as, "How do I get my lure to SWIM, on its own, by using the right line diameter?" The LINE itself plays a huge part in how the fly is presented...errrm, I mean 'the spinner'...