The Environment Agency were down on the river today (thanks Robin for the text). They were surveying the Calder below the weir for numbers/species of fish. I hopefully we will get info from them.
Also spotted was a male Broad Bodied Blue Chaser Colinsia dukensii. They are sometimes seen skulking in low herbage. It was quite a bold specimen and approached me without fear and communicated with me in a strange tongue.
The debris on the overhanging branch gives an indication of the hight of the river during the recent floods.