you need a water bowl but you probably have something like that around the house. just make sure it's heavy so it doesn't get tipped over. i would put a heavy book or two on top of the enclosure just in case. locking lids are nice but it's a good precaution. you'd be surprised how they can houdini their way out.
*EDIT* btw, you should consider getting another tub. it's good to have a backup and having something to put the snake in while you're cleaning everything is a lifesaver.