We stayed at Island Park COE, Pine Flat Lake, Sanger, CA - near Fresno.
It was a 'waterfront' site.
The water was high at Island Park, but the camp site was above the spillway elevation, probably above the physical top of the dam elevation. There was nothing between my site and the water, but a steep bank. Too steep to walk down.
The problem with lakes, and rivers, is that the campsite needs to be above the elevation of maxium possible high water. There may even be an EPA rule about having sewer sites that could be flooded. I know that most of the COE parks in Texas have their sewer sites far above the lake level. Even waterfront sewer sites require a bit of a walk to the water.
Good luck.