So the suggestion is rising water tiles, or falling water plank or wtv.

I'm not a good map maker but what I imagine is either a moving water plank going up, or down from on the map.
Or a Water Plank expanding in one direction, so perhaps it can go one direction and stay there or go up and down in a cycle.

Possible problems may be bugs, lag, the usual stuff people say but i think it's possible that it could run smoothly. what do you guys think?

I think what you mean is a flow that goes up or down?

/Support

This was suggested alreaddy