I think Raleigh has one and/or possibly Cary, but check with the chamber of commerce or parks/rec. for each, we don't have one in our area that I know about.
Oh, Chamber is a good idea. I know there *used* to be one in Cary, and one up in North Raleigh. Someone, however, was telling me about something closer to us where they let their dogs do retrieving in the water. Can't recall where. Ugh! Frogger