Take the kids rafting with Shotgun Eddy Raft Rental.
You'll be floating down the Wolf River. There are rapids on the river. Usually they are pretty small and fun. There are some large ones at the end of the trip. But they warn you about those. So if you aren't comfortable with that, you can get out of the river and walk your raft down to the bus for the ride back.
Last Bit of Advice
Be sure to call ahead and ask about the water levels. If the water is low, you might have to pull your raft over a lot of shallow spots.