Continuing from the “Wind, Watermills and Axles” thread I open this thread for the Waterwheel addon for Gregtech I wrote.
You can download it here.
You can build the structure for the multiblock with any wood blocks and the Water Wheel Core in the center.
The structure needs to be rotation symmetric, but it only cares if there is an accepted block at the same place or not, so you can mix it up.
If it does not form right away just right-click it with a magnifying glass.