As you know by now, 1.13 is around the corner with some quite drastic changes to the way a lot of base game mechanics are working. Specifically, Items will float: This means that you can transport items vertically upwards in a water column. Interestingly, stuff dropped into 1-block high water with air below still falls through. It seems that a transport is best done with a dropper at the base of the water.
Anyone has a better way to insert items into a water column? Will you change your mob farms?