I have found the water parks to be tricky with my son with disabilities. One year we had a confrontation at the Blizzard Beach ski lift. My husband took my son over to the handicapped lift entrance, and waited for awhile. Finally he called over to a CM, and the CM asked many questions about WHY they needed to ride the lift. At one point, the CM said "he does not look that handicapped to ME". Of course, supervisors were called over, and that CM was "reassigned" to another area of the park for the day. (the rest of the family walked up the hill, we were not taking advantage) An isolated incident, but they were not trained to handle disabilites well at the water parks. (we asked for a GAC there, and they did not have them)
But, it is a tricky thing, and I can understand why it is difficult. We have Sean in his chair, and they have to put him into THEIR chair to ride to the top. We waited for the round gondola lift thing. Then they wanted him to get out and walk at the top, and the lines were really long for everything up there, like the family raft ride. We said, he can't wait in that long line, especailly barefoot, the kid has ankle problems. So, we insisted on keeping him in their chair, the rest of family waited on the line, and we cut him over to join them when they were near the front. Then, another CM had to come over to return that chair to the lift area. Meanwhile, Seans chair is at the bottom, near the chair lift, no where NEAR where he will end up coming off the slides..... So, we have to send one of us over to fetch it for him. A big hassle, but Sean loves the water slides, but cannot handle more than one walk up to the top. When he was small, my husband would carry him, but he is 17 now!
We now let him go down once, maybe twice, then he is in the lazy river until I take him home, right after lunch. He only lasts 1/2 day there.
I would guess that MAYBE a new water park would have an elevator or a winding path to the top, I dont know. Again, not a huge problem, we love the Disney water parks.