Im not too sure about the stock levels, but there are some very big carp in there.. I was a LBAC member a season ago, and went there a few times targeting the carp. In the first session I had a screaming run, which was obviously a catfish as it tore my arm off when trying to play it, and it snapped 20lb line coupled with a 25lb hooklink. I've caught big carp before, so it was definetly a cat.
The other few times I fished it I caught 2 carp, but these were only around 12lbs each. There are lots of bream in there too, but like I said there are carp in there, but how many I do not know :s