I was very excited to get a waterwheel going, but then very disappointed to find out it has durability and requires pretty expensive repair kits to maintain. I don't see any incentive to ever use water wheels over windmills considering windmills are so much cheaper and require zero maintenance. I get that the water wheel spins at a constant speed and isn't subject to random changes in wind, but I don't think that's enough to make it worth 32 iron ingots and 1 brass ingot (plus 6 steel ingots if you want flumes to power it overhead) to build AND a constant supply of even more steel ingots and leather to maintain - and that's just for ONE waterwheel, let alone multiple.