Where did you hear this? Inquiring minds want to know.
Anyway, I can tell you that Splashtown/Funtown in Maine actually does charge for water and/or ice. My son got heat exhaustion and my husband went looking for water for him. The first lady at the counter just handed him a cup full of water and ice, which really helped, but when we sent our daughter back for more there was a new lady there who grumbled at her and said she "wasn't allowed" to give water away "for free" and she'd do it "just this once" but next time my daughter would have to pay.
Maybe your source mixed up their parks?