Waterwheel
The waterwheel requires flowing water to function and can be stacked to increase the capacity amount of the network. The direction of the flowing water will determine the direction of rotation of the waterwheel, in order to make a waterwheel function, there are a few requirements to meet.
Generator details
Ground / Ceiling placement
Placing the waterwheel on the ground is possible, but is also the form with more requirements to meet. Each side of the waterwheel accepts flowing water, but a source is mandatory to be present on the edge of one of the sides.
Only 1 water source, the rest must be flowing water

Wall placement
Placing the waterwheel vertically, it can be powered from one of the sides, covering all the height of the wheel (3 blocks), no water source is needed.

They can also be powered from the bottom side, following the same rule as ground / ceiling placements.
Modder tip
You can configure the requirements for your generators through the asset editor
