How deep is Built-A-Raft River? The water in the Build-A-Raft River is 3 feet deep. Was this article helpful? Related articles Is the water heated in the Water Park? How long does it take to slide down the large slides in the Water Park? Can we use our own flotation devices for our toddlers? Can a special needs guest use their floating wheelchair in the Build-A-Raft River? What is included in a Cabana Rental?