Let me re-phrase that slightly, because I'm sure goalies used water bottles frequently long before 1985.
Who was the first goalie to place a water bottle on top of their net?
Interesting question. As I've already said, it did not start becoming standard practice until 1985, which is amazing when you think about it. The goalies back then would play the entire period without water breaks. There was no TV timeouts or scheduled breaks in action so wandering over to the bench for a beverage was not common.
No, it was not until the 1985 Philadelphia Flyers that goalies started attaching water bottles on top of their cage.
Some sources suggest it was Pelle Lindbergh who started the now accepted practice, though it appears it was his back up who actually began the trend.
Bob Froese placed the bottle on top of the net, much to ire of opposition, the Edmonton Oilers. The Oilers argued that the bottle would be falling off and spilling it's contents. Coach Glen Sather even quipped "What are they going to want up there next, a bucket of chicken?"
The referee allowed the bottle to remain because Froese had it strapped down with a strip of Velcro.
While this was the first such NHL usage of a water bottle, several weeks earlier the practice appeared in the NCAA championship tournament.
Both goaltenders Chris Terreri of Providence and Scott Gordon of Boston University took to their respective nets with water bottles in hand.
And so began the practice of placing water bottles on the top of the net. The rules do state that the water bottle must secured on top, though goalies rarely do nowadays. They like to place the bottle strategically in order to block overhead camera views, just in case there is a dispute if the puck actually crossed the goal line or not.