From Victor Adams:
I often visit the reserve at the Kirkby pits, and would be pleased to know just what went on when the old river Bain was bypassed by the weir. What was the reason and how did it work? If you could kindly explain it would end a lot of guessing and head scratching.
I don’t know the answer, but if you do, please get in touch with Victor: firstname.lastname@example.org