Updated Oct 26, 2021 - Completely redesigned from scratch to be more durable, retain its sheeting effect for a greater distance, and have a better fitting connector for NPT 1/2" shower connectors used in the US. Folks not using that connector type should probably use the older files, not the "Improved" file.

I recommend printing this slowly, at the highest temperature your filament will tolerate, in .2mm layer heights and 100% infill for best results. The new version should work well with PLA, but for greater durability I recommend using PETG (best choice) or ABS.

Very simple remix: I added additional reinforcement / reduction of the water flow space to increase velocity of the waterfall in lower water pressure situations, and I also removed some of the lower non-threaded portion of the stem to more easily fit more curved faucet taps.

One side benefit of this design; if you have the shower head mounted a good 8' high like I do, and you crouch down a bit, it gives one heck of a pounding back massage.

Obviously water is self-attracting. It won't look like a waterfall all the way to ground level. But it's better that it doesn't, for my purposes at least.

UPDATE 5/2021

Added an even more restricted flow head for even lower water pressures. I recommend using only ABS for this. Still no supports required, but use a brim to keep it glued down.