Wonder if someone's looking at the drainage response times from Middlepeak quarry? I'll try and remember to mention this to John Gunn at the upcoming UCF meeting and see if he knows.
Scud on hear has already been in touch with John Gunn , I sent him some details via PM to pass on. I believe there are a couple of sough levels that feed into Hange brook which sparked the question.
There were three - Hannage, Northcliffe and Rantor, though they don't discharge much now given the deeper drainage into Cromford and Meerbrook Soughs. I think Hannage is the only one that still has any real outflow.