Bingo. Waterfalls are a truly bad idea. Anything that can cause a sustained wet area in a cage is a bad idea, for the bacteria reasons stated. Crickets will inevitably create a septic situation where sustained moisture is present, and then transfer that higher bacteria counts to your chameleon. Trays or dishes under potted plants are just as notorious. With all due respect, waterfalls are to please the eyes of the owner, and not improve the habitat of the chameleon. As has been said, really bad idea. Add a pretty plant, etc.
The Chameleon Company, LLC