You can get water for your drink, we did it several times. Enjoy the dining plan it is great
Per the sticky Thread at the top of this thread
For each night of your package, the
Disney Dining Plan includes the following meals for each Guest in your
o One (1) Table-Service Meal
Includes appetizer, entree, dessert or full buffet and non-alcoholic beverage as well as gratuity (children ages 3-9 must choose from the children's menu if available; appetizer & dessert not available at breakfast but juice is
o One (1) Counter-Service Meal
Includes entree, dessert or one complete combo meal, and non-alcoholic beverage (children ages 3-9 must choose from the children's menu if available)** dessert not available at breakfast
o One (1) Snack
What Can You Get With Snack Credits?
As of May 2006, Disney has expanded the items available with Dining Plan snack credits. Disney is now generally defining a "snack" on the Disney Dining Plan be an item under $4 (pre-tax), edible, non-alcoholic, non-merchandise and non-souvenir. Some items such as pizza slices are excluded.
Snacks can be redeemed at quick service or snack cart locations only. Quick-service and snack cart locations display a "dining plan" logo on their menus indicating items for which you can use your snack credits.
Among the items now available with Dining Plan snack credits:
ice cream novelty
frozen fruit bar
box of popcorn
12 oz soft drink
20 oz Powerade
24 oz bottle of water
piece of fruit
bottled fruit juice
flavored milk
snack-sized bag of chips
ice cream sundaes
ice cream floats
smoothies
nachos
bakery items
Mickey rice krispy treats