Yeah, that pisses me off too.
I haven't seen anyone lately though. But I've seen boats on the shore and people out in kayak's. Then of course the kids wading knee deep out into the water (also a no no), not to mention all the broken beer bottles and trash that's left behind around all the fire pits.
It's a freakin' reservoir. A public water supply!!!
Seriously, respect people. No one seems to have it anymore.