I have not read any other George Eliot before, but I'm tackling authors I feel I ought to have read.
The whole book depends on the 'fall' of the Tulliver family following Mr T's loss of a lawsuit.
He is in dispute with Mr Pivart, over his taking water from the Floss upstream from the mill for an irrigation scheme, affecting the flow at Dorlcote and therefore the viability of the mill.
So: Mr Tulliver loses and is ruined by the legal costs. The mill, however, continues to run and Tom devotes his life to restoring its ownership to the Tulliver family.
Surely if Mr Pivart has won, and can abstract water from the river, then the mill is no longer functional, Tom has nothing to work for and the entire story is, frankly, dodgy?