We were up there about a month ago. There had been rain and the release was 97 cubic feet per second. Even then the river was low and slow, with butt dragging on rocks a few times. Drinking alcohol was no problem.
http://tubehaus.com/ We used this place. Excellent parking inside their area, which made me feel much better about leaving stuff in the truck. You walk a full block with your tube to get to the bridge where everyone gets in. The River makes a big horseshoe and goes back under the highway at the next bridge location. When you get out, you walk a block, cross the road (cross light) and phone for pickup, including gear and dogs for a ride back.
We liked tubehaus because they were dog friendly. Most of their tubes have plastic bottoms attached which serve like a skid plate and a great advantage over rocks. I rented an extra tube for the ice chest (which needs latches). They have "old rope/string" to tie the tubes together, but I was glad I brought my own.
Read through the rules an you will know all you need. There is a link to current conditions which provides flow rate. I would not want to go if the rate is under 100 cps.
One of our party brought a water proof boom box he had made with recorded music. It was outstanding!
If you do not get out when you hit the bridge area, then it is a much longer float to the next exit area (see website).
Be sure to clip the discount coupon for each day you will be there. My son got a bigger discount by being military.
Old Dingus