There is definitely one and possibly two second broods of Red-Necked Grebes at Colonel Sam Smith Park. Walking in the park this evening, my wife noticed an adult grebe carrying a minnow toward the raft closest to the yacht club. Sure enough, a tiny chick popped out to accept it. Judging from the posture of the adult on the nest, there were likely more chicks hiding under its wings.
It was evening and the light wasn't good, but I suspect there may be chicks at the raft on the south side opposite the docks (orange marker). The adult on that nest appeared to be holding its wings up off its body as if there was something underneath.
BB