I'm catching fish shallow on Ray Hubbard. I would think you can get them shallow on Grapevine as well. I haven't been since last year but I have had a lot of luck in the past on the south west end of grapevine. It's very shallow so you may have to wade out to cast far enough. Take White Chapel Blvd all the way north until it dead ends into a trail head, then its a semi-short walk to the water.