I would say hardly any unless the builder of the wheel damages the stream/river being used to power the wheel....water wheels use to be everywhere until hydro dam use came into being used in place of waterwheels...there are many many historical water wheels still in use in the united states today producing electricity,power to grind grain into flour,saw mills,even used to make ice cream at one time...even poor countries use animal driven wheels to pump water into their farm fields...
