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.
Going to launch the kayak at Trophy Club in the morning and drift to the main lake. I'll report back.
Sorry to report a total washout on the catfish at Trophy Club. Another rain storm will change that though I'm sure because I caught 5 there right after the last deluge, Blues, Channels, and Flatheads. From the bank on fresh shad.
I took my kayak down Denton Creek (launched from Trophy Club Park) and paddled down to the main lake yesterday. The creek was full of shad, I caught some with my castnet and set 6 jug lines out. I ended up catching 2 channel catfishes, probably could have caught more but I was only out for 3 hours.