Just to add some clarity to the whole shebang  those water...

Just to add some clarity to the whole shebang  those water wheels you speak off are in the south of the state more often in rice growing areas . They are part of a water delivery system run by the state water body . Water is lifted by pump into a large chanel that takes the water a long way from the river , long those channels water wheels are used to meter the flow out of the Govt owned channels into the farms own system . So the Govt owned pump lifts the water from the river & the govt owned wheel meters it . I think the furthest north you will find them is around Narromine.Thats how it works up north in cotton country the farmer owns the pump & lifts the water into storages during times of high stream flow , the meter is on those pumps. Bores are another deal altogether. Not sure how much is lost to seepage in those Govt owned channels but I think its a lot.