I have fished it a few times with lures, hoping for a Pike or two, but have only caught small Browns...but that was a good 20 years ago.
I know several tackle shops in Aberdeen used to send kids up there as it was relatively safe fishing. Again, brownies.
However in more recent times its been fished heavily and I am not sure what would be left, if anything. My last walk around the place was about 2 years ago and there were signs of camp fires and a fair bit of rubbish laying about.
I am pretty certain that there used to be a sign up on the dam wall saying in an emergency call Aberdeenshire Council, so I guess they maybe own it? As you say, its looking very overgrown and if you look on google maps, sat view, you can see the old outline of the water. Its lost perhaps a third of its size.
parking was always a bit iffy as well, with stories of cars being broken into.