Is there a place to change out of swimsuits if you have played in the fountains?

Yes, located in the building by the parking lot...other side of the play ground if you are standing in the splash park area

Yes, there are restrooms for people to change into/out of near children's fountain.

Clean restrooms just across the children fountain

There are restrooms on site

Someone know if the splash water is turned on?

Yes restroom is near splash park

Yes, and the place is very clean.

Yes