In reply to johncook:
> I have never plucked up the courage to go in, but it is not very deep now. Back in the day it was about 2m deeper. The level has dropped considerably over the years. It used to be up to the bottom of Once Pegged Wall and Limpopo groove, and access to the large ledge at the back was up one of the easier routes and down climb to it. It also was extremely smelly and foetid on a hot summers day!
As you say, it is a stinking mess.
Its only a ( man made ) quarry, but very popular.
Why don't the locals look at the options for draining or filling it in?