I have some different information in regards to this question....
My best friend and I took our two 9-year olds last August and we had a real problem during our day at Blizzard Beach. Both kids had a pair of goggles. My daughter didn't actually need them, but my friend's son wasn't at all comfortable swimming without them. We attempted to come down the first slide and my friend and I went down first, telling the kids we'd be waiting for them at the bottom. My daughter came down next (with no goggles on) and we waited and waited, but no Michael. We finally saw him coming down the stairs and he told us that the lifeguard at the top wouldn't let him go down with his goggles on.
So...we went to the large wave pool and the kids were swimming around in there, when they were once again "yelled" at by a lifeguard. I didn't say anything but as I looked around, I saw dozens of kids in goggles. Needless to say, I was VERY confused. I finally spoke with a very helpful lifeguard who explained to me that the goggles cannot have a nose cover. The nasal passage cannot be covered. This was actually the only helpful lifeguard we encountered. In the meantime, my friend was consulting with the less than helpful lifeguard who told her that the rule was stated in the park map/directory which we were given when we purchased our tickets. Well, my friend proceeded to read the directory from start to finish and no where was this stated. She ended up in Guest Relations where some JERK informed her that if she'd taught her son to swim in the correct way, he wouldn't need the goggles. He then offered her a pair of nose plugs for her son to use - confusing??? He can wear eye goggles and nose plugs, but not eye goggles with built in nose plugs? She came back to me FUMING!!! At this time, I was still visiting with the "nice" lifeguard and she immediately called the director of Blizzard Beach who came right out and talked to us. He was very nice and apologized over and over for the rude personnel in Guest Relations. He stated that he knew the statement had been taken out of the park map, and that it was a very confusing issue. He said that the information needed to be posted at the ticket window - before people bought their admission. He ended up telling us to have lunch, enjoy the lazy river and when we were ready to leave, he would gladly refund us our admission price.
I can't speak for the resort pools, but if you go to one of the water parks, be sure that your goggles don't have nose plugs.