In haste I think I misunderstood your post. For a moment I thought you weren't planning on carrying water. And I agree, drinking every 5 minutes isn't a good strategy. Every 30-60 minutes depending on the individual should suffice.
As a general warning I'd recommend you guys bring food. You could start at 9am or 1pm. If you start late you'll want to keep your body fuelled up and ready to go.
I ate a light breakfast in the summer in anticipation of a 9AM start. Fortunately I had some trail mix in the car, but the high fat/fiber stuff isn't what I'd generally eat before a run.